McQuay ALS 070A Installation Manual

Installation, Operation and Maintenance Manual

Air-Cooled Screw Compressor Chiller

ALS 070A through 425A

60 Hertz

IOMM ALS-1

Group: Chiller
Part Number: 070774401
Date: June 1999
Supersedes: IOMM ALS

© 1996 McQuay International

Table Of Contents

Introduction.............................3

General Description........................................3

Nomenclature...................................................3

Inspection........................................................3

Installation and Start-up ............3

Handling...........................................................4

Location............................................................6

Service Access................................................6

Clearance Requirements.................................7

Vibration Isolators.........................................10

Water Piping..................................................12

Evaporator Freeze Protection......................13

Flow Switch....................................................14

Water Connections.......................................15

Refrigerant Charge........................................15

Glycol Solutions............................................15

Remote Evaporator................16

General............................................................16

Startup Procedures .......................................20

Dimensions, Remote Evaporator................22

Water Flow and Pressure Drop25

Physical Data ......................... 27

Major Components................30

Compressor Staging ..............32

Dimensional Data...................34

Unit Layout and Principles of

Operation.............................. 59

Major Component Location.........................59

Control Center ................................................60

Sequence of Operation.................................62

Start-up and Shutdown.......... 64

Seasonal Start-up..........................................64

Temporary Shutdown ...................................64

Start-up After Temporary Shutdown..........65

Extended Shutdown......................................65

Start-up After Extended Shutdown.............66

System Maintenance.............. 67

General............................................................67

Compressor Maintenance............................67

Lubrication.....................................................67

Electrical Terminals........................................67

Condensers ....................................................67

Refrigerant Sightglass..................................68

Lead-Lag.........................................................68

Preventative Maintenance Schedule..........69

Service.................................. 70

Compressor Solenoids..................................70

Filter-Driers.....................................................70

Liquid Line Solenoid Valve..........................71

Liquid Injection Solenoid Valve..................72

Electronic Expansion Valve..........................72

Electronic Expansion Valve Operation.......73

Evaporator......................................................74

Refrigerant Charging.....................................74

Electrical Data........................39

Field Wiring....................................................39

Wire Sizing Ampacities.................................40

Compressor and Condenser Fan Motors..47

Customer Wiring...........................................50

Electrical Data Notes ....................................56

Electrical Legend...........................................57

Typical Field Wiring Diagram......................58

In-Warranty Return Material

Procedure ............................. 76

Standard Controls ................. 77

Optional Controls ..........................................85

Controls, Settings and Functions...............87

Troubleshooting Chart.................................88

Periodic Maintenance Log...........................90

Our facility is ISO 9002 Certified

"McQuay" is a registered trademarks of McQuay International

"Illustrations cover the general appearance of McQuay International products at the time of publication and we reserve the right to

make changes in design and construction at anytime without notice"

2 IOMM ALS-1

Initial Issue January 1998



1996 McQuay International

Introduction

Liquid Injected

General Description

McQuay air-cooled water chillers are complete, self-contained automatic refrigerating units that
include the latest in engineering components arranged to provide a compact and efficient unit. Each
unit is completely assembled, factory wired, evacuated, charged, tested and comes complete and
ready for installation. Each unit consists of multiple air-cooled condensers with integral subcooler
sections, multiple accessible semi-hermetic single-screw compressors, replaceable tube multiple circuit
shell-and-tube evaporator, and complete refrigerant piping. Liquid line components included are
manual liquid line shutoff valves, charging valves, filter-driers, liquid line solenoid valves,
sightglass/moisture indicators, and electronic expansion valves. Other features include compressor
heaters, an evaporator heater for low ambient water freeze protection, automatic one time pumpdown
of refrigerant circuit upon circuit shutdown, and an advanced fully integrated microprocessor control
system.

Nomenclature

A L S - XXX A

Air-Cooled

Rotary Screw Compressor

Inspection

When the equipment is received, all items should be carefully checked against the bill of lading to
insure a complete shipment. All units should be carefully inspected for damage upon arrival. All
shipping damage must be reported to the carrier and a claim must be filed with the carrier. The unit’s
serial plate should be checked before unloading the unit to be sure that it agrees with the power
supply available. Physical damage to unit after acceptance is not the responsibility of McQuay
International.
Note: Unit shipping and operating weights are available in the Physical Data Tables.

Installation and Start-up

Note: Installation and maintenance are to be performed only by qualified personnel who are familiar
with local codes and regulations, and experienced with this type of equipment.

Sharp edges and coil surfaces are a potential injury hazard. Avoid contact with them.

Start-up by McQuayService is included on all units sold for installation within the USA and Canada.
Two week prior notification of start-up is required. The contractor should obtain a copy of the Start­up Scheduled Request Form from the sales representative or from the nearest office of
McQuayService.

Design Vintage

Nominal Tons

CAUTION

IOMM ALS-1 3

Handling

Care should be taken to avoid rough handling or shock due to impact or dropping the unit. Do not
push or pull the unit from anything other than the base, and block the pushing vehicle away from the
unit to prevent damage to the sheetmetal cabinet and end frame (see Figure 1).

Never allow any part of the unit to fall during unloading or moving as this may result in serious
damage.

To lift the unit, 2½ “ (64 mm) diameter lifting holes are provided in the base of the unit. Spreader bars
and cables should be arranged to prevent damage to the condenser coils or unit cabinet (see Figures 2
through 5).

Figure 1, Suggested Pushing Method Figure 2, Suggested Lifting Method, ALS 070-204

Figure 3, Suggested Lifting Method, ALS 205-280

4 IOMM ALS-1

Figure 4, Suggested Lifting Method, ALS 300-340

Figure 5, Suggested Lifting Method, ALS 360-425

IOMM ALS-1 5

Location

Care should be taken in the location of the unit to provide proper airflow to the condenser. (See
Figures 6 through 8 for required clearances).

Due to the vertical condenser coil design of the ALS 070A through ALS 425A chillers, it is
recommended that the unit be oriented so that prevailing winds blow parallel to the unit length, thus
minimizing the wind effect on condensing pressure and performance. If the unit is installed with no
protection against prevailing winds it is recommended that wind baffles be installed.

Using less clearances than shown in Figure 6, Figure 7, and Figure 8 will cause discharge air
recirculation to the condenser and could have a significant and detrimental effect on unit performance.
McQuay Application Manual, AM ALS/WHS, contains more detail on this subject.

Service Access

Each end of the unit must be accessible after installation for periodic service work. Compressors,
filter-driers, and manual liquid line shutoff valves are accessible on each side of the unit adjacent to
the control box. High pressure and low pressure transducers are mounted on the compressor. The
cooler barrel heater thermostat is located on the cooler. Compressor overloads, microprocessor, and
most other operational, safety and starting controls are located in the unit control box.

On all ALS units the condenser fans and motors can be removed from the top of the unit. The
complete fan/motor assembly can be removed for service. The fan blade and fan motor rain shield
must be removed for access to wiring terminals at the top of the motor.

WARNING

Disconnect all power to the unit while servicing condenser fan motors.

Failure to do so may cause bodily injury or death.

Do not block access to the sides or ends of the unit with piping or conduit. These areas must be open
for service access.

6 IOMM ALS-1

Clearance Requirements

Figure 6, Clearance Requirements, ALS 070-204

Notes:

1. Minimum side clearance between two units is 12 feet.

2. Unit must not be installed in a pit or enclosure that is deeper or taller than the height of the unit

unless extra clearance is provided per note 4.

3. Minimum clearance on each side is 8 feet when installed in a pit no deeper than the unit height.

4. Minimum side clearance to a side wall or building taller than the unit height is 8 feet provided no

solid wall above 6 feet is closer than 12 feet to the opposite side of the unit.

5. The removable post for compressor service access must not be blocked at either side of the unit.

6. Do not mount electrical conduits, etc, above the side rail on either side if the unit.

7. There must be no obstruction of the fan discharge.

IOMM ALS-1 7

Figure 7, Clearance Requirements, ALS 205-280

Notes:

1. Minimum side clearance between two units is 12 feet.

2. Unit must not be installed in a pit or enclosure that is deeper or taller than the height of the unit

unless extra clearance is provided per note 4.

3. Minimum clearance on each side is 8 feet when installed in a pit no deeper than the unit height.

4. Minimum side clearance to a side wall or building taller than the unit height is 8 feet provided no

solid wall above 6 feet is closer than 12 feet to the opposite side of the unit.

5. The removable post for compressor service access must not be blocked at either side of the unit.

6. Do not mount electrical conduits, etc, above the side rail on either side if the unit.

7. There must be no obstruction of the fan discharge.

8 IOMM ALS-1

Figure 8, Clearance Requirements, ALS 300-425

Notes:

1. Minimum side clearance between two units is 12 feet.

2. Unit must not be installed in a pit or enclosure that is deeper or taller than the height of the unit

unless extra clearance is provided per note 4.

3. Minimum clearance on each side is 8 feet when installed in a pit no deeper than the unit height.

4. Minimum side clearance to a side wall or building taller than the unit height is 8 feet provided no

solid wall above 6 feet is closer than 12 feet to the opposite side of the unit.

5. The removable post for compressor service access must not be blocked at either side of the unit.

6. Do not mount electrical conduits, etc, above the side rail on either side if the unit.

7. There must be no obstruction of the fan discharge.

IOMM ALS-1 9

Vibration Isolators

Vibration isolators are recommended for all roof mounted installations or wherever vibration
transmissions is a consideration. Figure 9,(070 thru 204), Figure 10 (205 thru 280), Figure 12 (300
thru 340) and Figure 13 (360 thru 425) give isolator locations in relation to the unit control center.
Table 2 (070 thru 204), Table 3 (205 thru 280), Table 4 (300 thru 340) and Table 6 (360 thru 425)
give the isolator loads at each location shown in Figures 9, 10, 12 and 13. Figure 11 gives dimensions
that are required to secure each McQuay isolator section to the mounting surface.

Table 1, Vibration Isolators (Spring)

ALS UNIT SIZE TYPE

125-280 CP2-32 White 0047792932 2600 (1180)

Note: The same isolators are used when the chiller is supplied with the optional copper finned
condenser coils. The spring is fully compressed at approximately 3900 lbs (1769 kg).

COLOR

OF

STRIPE

McQUAY PART

NUMBER

Table 2, Isolator Loads, ALS 070-204

ALS ISOLATOR LOADS AT EACH MOUNTING LOCATION

UNIT LBS (KG)
SIZE 1 2 3 4 5 6

070 1920 (871) N/A N/A 1332 (604( 1460 (662) N/A N/A 1013 (460)
080 2071 (939) N/A N/A 1437 (652) 1575 (715) N/A N/A 1092 (495)
090 1092 (495) 1229 (557) 1092 (495) 1092 (495) 1229 (557) 1092 (495)

100 1168 (529) 1314 (595) 1168 (529) 1168 (529) 1314 (595) 1168 (529)
125A 1625 (737) 2065 (937) 1270 (576) 1625 (737) 2065 (937) 1270 (576)
140A 1680 (762) 2145 (973) 1350 (612) 1680 (762) 2145 (973) 1350 (612)
155A 1720 (780) 2205 (1000) 1410 (640) 1720 (780) 2205 (1000) 1410 (640)
170A 1760 (785) 2220 (1007) 1425 (647) 1730 (785) 2220 (1007) 1425 (647)
175A 1880 (853) 2350 (1066) 1395 (633) 1880 (853) 2350 (1066) 1395 (633)
185A 1880 (853) 2350 (1066) 1395 (633) 1880 (853) 2350 (1066) 1395 (633)
195A 1920 (871) 2440 (1107) 1440 (653) 1920 (871) 2440 (1107) 1440 (653)
204A 2081 (944) 2644 (1199) 1560 (707) 2081 (944) 2644 (1199) 1560 (707)

RECOMMENDED

MAXIMUM LOAD

LBS. (KG)

Figure 9, Isolator Locations, ALS 070-204

Table 3, Isolator Loads, ALS 205-280

ALS ISOLATOR LOADS AT EACH MOUNTING LOCATION

UNIT LBS (KG)

SIZE 1 2 3 4 5 6 7 8 9 10
205A 1790 (812) 1840 (834) 2040 (925) 1370 (621) 950 (431) 1630 (739) 2020 (916) 1640 (744) 1650 (748) 1000 (454)
220A 1790 (812) 1850 (839) 2050 (930) 1370 (621) 950 (431) 1630 (739) 2030 (921) 1650 (748) 1660 (753) 1000 (454)
235A 1820 (825) 1880 (853) 5080 (943) 1370 (621) 960 (435) 1670 (757) 2060 (934) 1680 (762) 1660 (753) 1000 (454)
250A 1820 (825) 1880 (853) 2080 (943) 1380 (626) 960 (435) 1670 (757) 2060 (934) 1680 (762) 1670 (757) 1000 (454)
265A 1820 (825) 1880 (853) 2080 (943) 1380 (626) 960 (435) 1670 (757) 2060 (934) 1680 (762) 1670 (757) 1000 (454)
280A 1830 (830) 1890 (857) 2080 (943) 1380 (626) 960 (435) 1680 (762) 2070 (939) 1690 (766) 1670 (757) 1000 (454)

10 IOMM ALS-1

Figure 10, Isolator Locations, ALS 205-280 Figure 11, Spring Flex Isolators

Table 4, Isolator Loads, ALS 300 - 340

ALS OPERATING
UNIT ISOLATOR LOADS AT EACH MOUNTING LOCATIONS, lb (kg) WEIGHT
SIZE 1 2 3 4 5 6 7 8 9 10 LBS (KGS)

300A 1780 (807) 2060 (934) 2530 (1147) 2530 (1147) 2560 (1161) 2560 (1161) 2170 (984) 2170 (984) 1445 (655) 1445 (655) 21250 (9637)
315A 1780 (807) 2060 (934) 2530 (1147) 2530 (1147) 2560 (1161) 2560 (1161) 2170 (984) 2170 (984) 1445 (655) 1445 (655) 21250 (9637)
330A 1780 (807) 2060 (934) 2540 (1152) 2540 (1152) 2570 (1166) 2570 (1166) 2180 (989) 2180 (989) 1450 (658) 1450 (658) 21320 (9669)
340A 1780 (807) 2060 (934) 2540 (1152) 2540 (1152) 2570 (1166) 2570 (1166) 2180 (989) 2180 (989) 1450 (658) 1450 (658) 21320 (9669)

Note:

1. Unit to be supported at (5) isolator mounting locations per side, 10 total, as indicated.

2. Add approximately 370 lbs (168 kgs) at each isolator location for unit with optional copper finned condenser coils.

3. Unit to be level in both directions within 1/8 inch (3 mm) per 10 feet (3 m).

4. See dimensional drawing 073124701 for exact location of isolator support holes in base frame.

Figure 12, Vibration Isolators, ALS 300-340

Table 5, Vibration Isolators (Springs)

ALS UNIT SIZE TYPE OF MAXIMUM LOAD

COLOR RECOMMENDED

STRIPE

300A-340A CP2-32 White 047792932 3000 (1360)

Note: The same isolators are used when the chiller is supplied with the optional copper finned
condenser coils. The spring is fully compressed at approximately 3900 lbs (1769 kgs).

McQUAY PART

NUMBER

LB (KG)

Table 6, Isolator Loads, ALS 360-425

ALS

UNIT

SIZE 1 2 3 4 5 6 7 8 9 10 11 12
360A 1780 807 2060 934 2530 1147 2530 (1147) 2540 1152 2540 (1152) 1670 (757) 1670 (757) 1720 (780) 1720 (780) 1080 (490) 1080 (490)
370A 1780 807 2060 934 2540 1152 2540 (1152) 2550 1156 2550 (1156) 1675 (760) 1675 (760) 1720 (780) 1720 (780) 1080 (490) 1080 (490)
380A 1780 807 2060 934 2550 1156 2550 (1156) 2560 1161 2560 (1161) 1680 (762) 1680 (762) 1720 (780) 1720 (780) 1080 (490) 1080 (490)
425A 1846 837 2126 964 2616 1186 2616 (1186) 2626 1190 2626 (1190) 1746 (791) 1746 (791) 1768 (801) 1768 (801) 1146 (520) 1146 (520)

Note:

1. Unit to be supported at (6) isolator mounting locations per side, 12 total, as indicated.

2. Add approximately 370 lbs (168 kgs) at each isolator location for units with optional copper finned condenser coils.

ISOLATOR LOAD AT EACH MOUNTING LOCATIONS, lb (kg) .

IOMM ALS-1 11

3. Unit to be level in both directions within 1/8 inch (3mm) per 10 feet (3 m).

4. See dimensional drawing 073124801 for exact location of isolator support holes in base frame.

Figure 13, Vibration Isolators, ALS 360-425

Table 7, Vibration Isolators (Spring)

ALS UNIT SIZE TYPE OF MAXIMUM LOAD

COLOR RECOMMENDED

STRIPE

360A CP2-32 White 047792932 3000 (1360)

Note: The same isolators are used when the chiller is supplied with the optional copper finned condenser
coils. The spring is fully compressed at approximately 3900 lbs (1769 kgs).

MCQUAY PART

NUMBER

LBS (KG)

Water Piping

Due to the variety of piping practices, it is advisable to follow the recommendations of local
authorities. They can supply the installer with the proper building and safety codes required for a
safe and proper installation.

Basically, the piping should be designed with a minimum number of bends and changes in elevation to
keep system cost down and performance up. It should contain:

1. Vibration eliminators to reduce vibration and noise transmission to the building.

2. Shutoff valves to isolate the unit from the piping system during unit servicing.

3. Manual or automatic air vent valves at the high points of the system. Drains at the low parts in

the system. The evaporator should not be the highest point in the piping system.

4. Some means of maintaining adequate system water pressure (e.g., expansion tank or regulating

valve).

5. Water temperature and pressure indicators located at the unit to aid in unit servicing.

6. A strainer or some means of removing foreign matter from the water before it enters the pump.

The strainer should be placed far enough upstream to prevent cavitation at the pump inlet
(consult pump manufacturer for recommendations). The use of a strainer will prolong pump life
and help maintain high system performance levels.

7. A strainer should also be placed in the supply water line just prior to the inlet of the evaporator.

This will aid in preventing foreign material from entering and decreasing the performance of the
evaporator.

8. The shell-and-tube evaporator has a thermostat and heating cable to prevent freeze-up down to ­20°F (-28.8°C). It is suggested that the heating cable be wired to a separate 110V supply circuit.
As shipped from the factory, it is factory wired to the control circuit. Any water piping to the unit
must also be protected to prevent freezing.

12 IOMM ALS-1

9. If the unit is used as a replacement chiller on a previously existing piping system, the system

should be thoroughly flushed prior to unit installation and then regular chilled water analysis and
chemical water treatment is recommended immediately at equipment start-up.

10. The total water quantity in the system should be sufficient to prevent frequent "on-off" cycling.

A reasonable minimum quantity would allow for a complete water system turnover in not less than
15 minutes. See Application Manual, AM ALS/WHS for more detail on this subject.

11. In the event glycol is added to the water system, as an afterthought for freeze protection,

recognize that the refrigerant suction pressure will be lower, cooling performance less, and water
side pressure drop greater. If the percentage of glycol is large, or if propylene is employed in lieu
of ethylene glycol, the added pressure drop and loss of performance could be substantial.

12. For operations requiring the ice mode feature, logic in MicroTech will adjust the freezestat to a
pressure equivalent to 13.5°F (7.5°C) below the leaving evaporator water temperature. However, if
a different freezestat pressure value is desired, the freezestat can be manually changed through
MicroTech. Refer to IM549-1 for additional information.

WARNING

If a separate disconnect is used for the 110V supply to the cooler heating cable, it should be clearly
marked so that it is not accidentally shut off during cold seasons.

Prior to insulating the piping and filling the system, a preliminary leak check should be made.
Piping insulation should include a vapor barrier to prevent moisture condensation and possible

damage to the building structure. It is important to have the vapor barrier on the outside of the
insulation to prevent condensation within the insulation on the cold surface of the pipe.

Evaporator Freeze Protection

All evaporators come equipped with thermostatically controlled heat tape. When power is applied to
terminals 13 and 16, the heat tape will provide freeze protection down to -20°F (-28.8°C). However, this
should not be the only method of freeze protection. Unless the evaporator is flushed and drained as
is described below in note 4, two or more of the remaining three recommendations must be followed as
part of the system design:

1. Continuous circulation of water through the piping and the heat exchanger.

2. The inclusion of glycol solution in the chilled water circuit.

3. The addition of insulation and heat to the exposed piping.

4. Draining and flushing the chiller vessel with glycol during subfreezing weather.

It is the responsibility of the installing contractor and/or on-site maintenance personnel to insure that
this additional protection is provided. Routine checks should be made to insure adequate freeze
protection is maintained.

Failure to do so may result in damage to unit components. Freeze damage is not considered a
warranty failure.

IOMM ALS-1 13

Figure 14, Typical Field Water Piping

Vent

Outlet

Valved

pressure

gauge

Vibration

Eliminator

Flow

Switch

Balancing

valve

Gate valve

Protect all field piping
against freezing

Drain

Vibration

Eliminator

Water

strainer

Gate valve

Flow Switch

A water flow switch must be mounted in either the entering or leaving water line to insure that there
will be adequate water flow to the evaporator before the unit can start. This will safeguard against
slugging the compressors on start-up. It also serves to shut down the unit in the event that water
flow is interrupted to guard against evaporator freeze-up.

A flow switch is available from McQuay under ordering number 0017503300. It is a "paddle" type
switch and adaptable to any pipe size from 1" (25mm) to 8" (203mm) nominal.

Certain minimum flow rates are required to close the switch and are listed in Table 8. Installation
should be as shown in Figure 15.

Electrical connections in the unit control center should be made at terminals 62 and 63. The normally
open contacts of the flow switch should be wired between these two terminals. Flow switch contact
quality must be suitable for 24 VAC, low current (16ma). Flow switch wire must be in separate conduit
from any high voltage conductors (115 VAC and higher).

Figure 15, Flow Switch Table 8, Switch Minimum Flow Rates

1 1/4" (32mm) pipe dia.

Min. after switch

Flow direction marked

on switch

1" (25mm) NPT flow

switch connection

Tee

1 1/4" (32mm) dia.

Min. before switch

NOMINAL PIPE SIZE

INCHES (MM)

5 (127) 58.7 (3.7)
6 (152) 79.2 (5.0)
8 (203) 140 (8.8)

Note: Water pressure differential switch is not recommended for
outdoor applications.

MINIMUM REQUIRED FLOW TO
ACTIVATE SWITCH - GPM (LPS)

14 IOMM ALS-1

Water Connections

()()(

)

Water piping to the cooler can be brought up through the bottom of the unit or through the side
between the vertical supports. The dimensional data in Figure 23 through Figure 27 give the
necessary dimensions and locations for all piping connections.

Note: On unit size 175A through 204A there is a diagonal brace off of a vertical support which will
interfere with the water connection if brought in from the side. This brace can be removed, but only
after the unit is in place.

Refrigerant Charge

All units are designed for use with HCFC-22 (and are compatible with some HCFC alternatives) and are
shipped with a full operating charge. The operating charge for each unit is shown in the Physical Data
Tables.

Glycol Solutions

The chiller's capacity when using glycols, glycol solution flow rate and pressure drop through the
cooler may be calculated using the following formulas and tables.

Note: The procedure below does not specify the type of glycol. Use the derate factors found in Table
9 for corrections when using propylene glycol and those in Table 10 for ethylene glycol.

1. Capacity - Cooling capacity is reduced from that with plain water. To find the reduced value
multiply the chiller’s water system tonnage by the capacity correction factor to find the chiller’s
capacity when using glycol.

2. Flow - To determine flow (or delta-T) knowing delta-T (or flow) and capacity:

tons flowfactor

GPM

24

Delta T=−

3. Pressure drop - To determine pressure drop through the cooler, when using glycol, enter the
water pressure drop curve, Figure 21 or Figure 22,at the actual glycol flow. Multiply the water
pressure drop found there by the PD factor to obtain corrected glycol pressure drop.

4. To determine glycol system kW, multiply the water system kW by factor called Power.

Test coolant with a clean, accurate glycol solution hydrometer (similar to that found in service
stations) to determine the freezing point. Obtain percent glycol from the freezing point table below.
On glycol applications the supplier normally recommends that a minimum of 25% solution by weight
be used for protection against corrosion.

CAUTION

Do not use automotive grade antifreeze. Industrial grade glycols must be used. Automotive antifreeze
contains inhibitors that will cause plating on the copper tubes within the chiller evaporator. The type
and handling of glycol used must be consistent with local codes.

Table 9, Propylene Glycol

FREEZE

%

E.G.

10 26 -3 0.987 0.992 1.010 1.068
20 19 -7 0.975 0.985 1.028 1.147
30 9 -13 0.962 0.978 1.050 1.248
40 -5 -21 0.946 0.971 1.078 1.366
50 -27 -33 0.965 0.965 1.116 1.481

PT.

oFo

CAP POWER FLOW PD

C

Table 10, Ethylene Glycol

FREEZE

%

E.G.

10 26 -3 0.991 0.996 1.013 1.070
20 18 -8 0.982 0.992 1.040 1.129
30 7 -14 0.972 0.986 1.074 1.181
40 -7 -22 0.961 0.976 1.121 1.263
50 -28 -33 0.946 0.966 1.178 1.308

PT.

oFo

CAP POWER FLOW PD

C

IOMM ALS-1 15

Remote Evaporator

General

The multiple compressor ALS air-cooled chillers are available with remote evaporator. This allows the
main unit to be installed outdoors to save interior room and eliminates the need for anti-freeze
solutions and heat tracing of chilled water lines since the chilled water system is indoors. There are
some general guidelines to review before proceeding:

1. Applies to Models ALS 125 through ALS 425.

2. R-22 only.

3. Maximum line length of 50 ft (15 m) and Total Equivalent Length (TEL) of 120 ft (37 m).

4. Evaporator not more than 6 ft (1.8 m) above the compressor or 16 ft (5 m) below compressor.

5. No underground piping.

6. No hot gas bypass.

7. Units with remote evaporator are not included in the ARI Certification Program.
The remote evaporator is shipped separately, ready for quick and easy installation at the job site. All

refrigerant accessories such as liquid-vapor line shut-off valves, replaceable core filter-driers, liquid
line solenoid valves, electronic expansion valves, and sightglasses are already included on the ALS
condensing unit. The evaporator is equipped with entering and leaving chilled water temperature
sensor wells. The sensors are pre-wired to the ALS unit with 75 feet long sensor leads that must be
field connected to the evaporator thermowells. Suction pressure transducers and temperature sensors
must also be relocated to the evaporator. ALS units are factory charged with a full unit charge
including 10 feet (3 meters) of refrigerant line. Field piping must be leak tested, evacuated and charged
during installation. Do not exceed 150 psig test pressure unless the unit is blanked off from the
piping.

Performance Derate Factors

All performance tables and adjustment factors found in the air-cooled screw chiller catalog (PM ALS-

1) are applicable for remote evaporator installations. However, a performance derate must be applied
to the R-22 performance data due to additional pressure drops in the suction and liquid lines which
cause a loss of compressor performance. These derates are based on a suction line pressure drop
equivalent of approximately 2°F (1°C) change in saturation temperature.

For R-22 applications:

Capacity = Tons(kW) x 0.97
Power = Compressor kW x 0.99

Suction Lines

General

Careful design of the refrigerant piping is necessary for efficient system operation. The refrigerant
piping should be designed for a low pressure drop to obtain maximum capacity and efficiency while
maintaining adequate velocity. Lines should slope in the direction of flow to assure good oil return to
the compressors. Cost considerations favor keeping line sizes as small as possible while not
exceeding acceptable pressure drops in order to maintain unit performance.

NOTE

All refrigerant piping must be reviewed by McQuay Application Engineers prior to

order entry and will be verified by McQuay startup technicians.

16 IOMM ALS-1

Suction line sizing

Pressure drop in the suction line reduces system capacity and efficiency because it forces the
compressor to operate at lower suction pressure. The suction line should be sized for a pressure drop
approximately equivalent of 2°F (1°C) change in saturation temperature. For suction line sizing see
Table 11 through Table 13. For applications with the evaporator below the ALS unit, the vertical
section of the suction lines must be sized to return oil to the compressors at the minimum compressor
capacity step.

Example of Suction Line Size Calculation

ALS140A condensing unit with refrigerant R-22
Evaporator located 5 feet below the ALS compressor.
Lineal length of horizontal suction line is 25 feet
Suction line requires 7 long radius (90°) elbows; 3 in the horizontal, 4 in the riser

From Table 11, the nominal circuit capacities for circuit 1 and 2 are 65 and 80 tons respectively

Total lineal suction line length = 30 feet each circuit (25 feet horizontal plus 5 feet vertical riser).
For the first try, assume that the total equivalent suction line length is twice the lineal suction line
length.

Therefore the estimated total equivalent suction line length = 60 feet

From Table 12 and Table 13, For nominal circuit capacities of 65 & 80 tons and equivalent line length of

60 ft, the suction line size = 2 5/8" for horizontal lines and 2 1/8" for vertical lines.

From Table 16, Fitting loss for 2 5/8" long radius (90°) elbow = 4.1 ft, and 3.3 ft for the 2 1/8 elbows.

Therefore fitting loss in equivalent feet of pipe for (3) 2 5/8" long radius (90°) elbow = 12.3 ft, and

13.2ft for (4) 2 1/8" elbows.
Therefore the actual equivalent suction line length = 30 + 12.3 + 13.2 = 55.5 feet

From Table 12 and Table 13, For nominal circuit capacities of 65 & 80 tons and equivalent line length of

55.5 ft the suction line size is correct.

Table 11, ALS 125A-280A Nominal Circuit Capacities

ALS Model

125A 65 (229) 65 (229) - ­140A 65 (229) 80 (262) - ­155A 80 (262) 80 (262) - ­170A 80 (262) 95 (334) - ­175A 80 (262) 95 (334) - ­185A 95 (334) 95 (334) - ­195A 95 (334) 95 (334) - ­204A 95 (334) 95 (334) - ­205A 65 (229) 65 (229) 80 (262) ­220A 65 (229) 80 (262) 80 (262) ­235A 80 (262) 80 (262) 80 (262) ­250A 80 (262) 80 (262) 95 (334) ­265A 80 (262) 95 (334) 95 (334) ­280A 95 (334) 95 (334) 95 (334) ­300A 65 (229) 65 (229) 80 (262) 80 (262)
315A 65 (229) 80 (262) 80 (262) 80 (262)
330A 80 (262) 80 (262) 80 (262) 80 (262)
340A 80 (262) 80 (262) 80 (262) 95 (334)
360A 80 (262) 80 (262) 95 (334) 95 (334)
370A 80 (262) 95 (334) 95 (334) 95 (334)
380A 95 (334) 95 (334) 95 (334) 95 (334)
425A 95 (334) 95 (334) 95 (334) 95 (334)

Circuit 1 Circuit 2 Circuit 3 Circuit 4

Tons (kW) Tons (kW) Tons (kW) Tons (kW)

IOMM ALS-1 17

Table 12, Vertical Upflow Suction Line Sizes

Nominal Circuit

Capacity

Tons (kW) Equivalent Line Length Ft (m) Suction Line Size (in.)

65 (2290

80 (262)

95 (334)

Vertical Upflow Suction Lines

40 (12) 2 1/8
75 (23) 2 1/8
40 (12) 2 1/8
75 (23) 2 1/8
40 (12) 2 5/8
75 (23) 2 5/8

Table 13, Horizontal and Vertical Downflow Suction Line Sizes

Capacity

Tons (kW)

65 (229) 75 (23) 2 5/8

80 (262) 75 (23) 2 5/8

95 (334) 75 (23) 3 1/8

Vertical Downflow and Horizontal Suction LinesNominal Circuit

Equivalent Line Length Ft (m) Suction Line Size, in.

40 (12) 2 5/8

115 (35) 2 5/8

40 (12) 2 5/8

115 (35) 3 1/8

40 (12) 2 5/8

115 (35) 3 1/8

Liquid-Vapor Lines

The liquid-vapor line from the ALS condensing unit to the evaporator liquid connection is not a
conventional liquid line since it carries both liquid and vapor. The compressors on the ALS units
utilize a liquid cooled motor and an economizer. Therefore the expansion valve which feeds the full
flow of liquid refrigerant into the compressor for motor cooling is mounted in the liquid line between
the condenser sub-cooling coil and the compressor inlet; not at the evaporator inlet. The liquid-vapor
line to the evaporator is a low pressure line downstream of the expansion valve and the size is slightly
larger than a normal liquid line. For liquid line sizing see Table 14 and Table 15.

Table 14, Vertical Upflow Liquid-Vapor Line Sizes

Capacity

Tons (kW)

65 (2290

80 (262)

95 (334)

Equivalent Line Length

Vertical Upflow Liquid-Vapor LinesNominal Circuit

Ft (m)
40 (12) 1 3/8
75 (23) 1 3/8
40 (12) 1 3/8
75 (23) 1 3/8
40 (12) 1 5/8
75 (23) 1 5/8

Liquid-Vapor Line Size

o.d (in.)

Table 15, Horizontal and Vertical Downflow Liquid-Vapor Line Sizes

Capacity

Tons (kW)

65 (229) 75 (23) 1 3/8

80 (262) 75 (23) 1 5/8

95 (334) 75 (23) 1 5/8

Vertical Downflow and Horizontal Liquid-Vapor LinesNominal Circuit

Equivalent Line Length

Ft (m)
40 (12) 1 3/8

115 (35) 1 3/8

40 (12) 1 3/8

115 (35) 1 5/8

40 (12) 1 5/8

115 (35) 1 5/8

Liquid-Vapor Line Size

o.d (in.)

18 IOMM ALS-1

Insulation

All piping joints and fittings must be thoroughly leak tested before insulation is applied. Suction lines
must be insulated and should not be installed underground. Suction line insulation must be selected
to prevent condensation under local ambient conditions with the lines at 40°F to 50°F (4.4°C to 10°C)
operating temperatures. The liquid-vapor lines will operate at 40°F to 60°F (4.4°C to 15.6°C) and must
also be insulated to prevent sweating and heat gain.

Location and Arrangement

Refrigerant lines should be as short and direct as possible to minimize tubing and fittings. Long
radius elbows must be used (except for traps) to minimize the pressure drops. Traps should be as
short as possible to minimize oil accumulation. Refrigerant piping should be arranged so that normal
inspection of the equipment is not hindered. Adequate clearance should be provided between
refrigerant piping and adjacent walls for insulation. Piping should be run so that it does not interfere
with compressor service access, passages or obstruct headroom, windows and doors. Suction line
hangers must be sized and located to support the weight of the piping in accordance with good piping
practice.

Suction and liquid-vapor connection points for each circuit are labeled to facilitate field piping. Care
must be exercised in routing the piping to avoid mixing piping from different circuits. The circuits on
the outdoor ALS unit must match the circuits on the evaporator (i.e. circuit #1 on the outdoor ALS unit
must be connected with circuit #1 on the evaporator).

Horizontal portions of the suction lines must be downward sloping toward the compressors. Slope all
piping in the direction of flow. Vertical portions of the suction lines must be sized for oil return at
minimum compressor load.

Note: Double section risers must not be utilized on any circuit. Traps must be provided as shown on
Figure 16 and Figure 17.

Equivalent Line Lengths

Recommended refrigerant line sizes are based on equivalent line lengths of straight pipe, that is, a
combination of straight pipe, fittings and valves. The pressure drop through valves and fittings is
determined by establishing the equivalent straight length of pipe of the same size with the same
friction loss. The "Total Equivalent Length" is the sum of the "Lineal Line Length" and the
appropriate "Valve and Fitting Losses in Equivalent Feet of Pipe for Field Supplied Piping" given in
Table 16

Table 16, Fitting Equivalent Feet of Pipe

Line Size (in.) Angle Valve Globe Valve 90° Std. Radius Elbow 90° Long Radius Elbow

1 1/8 12 29 2.6 1.7
1 3/8 15 38 3.3 2.3
1 5/8 18 43 4.0 2.6
2 1/8 24 55 5.0 3.3
2 5/8 29 69 6.0 4.1
3 1/8 35 84 7.5 5.0

Figure 16, Evaporator Above ALS Unit

IOMM ALS-1 19

Figure 17, Evaporator Below ALS Unit

ALS Unit

Suction Line

Evaporator

Trap

NOTE: Keep the trap width at a minimum to avoid trapping excessive oil.

Startup Procedures

NOTE: McQuayService or an authorized McQuay service agent must do initial start-up and

commissioning.

Filter Driers

Following an initial 24 hour operation the pressure drop across the replaceable core, filter drier should
be checked. If this pressure drop exceeds the values given in Table 17 at the various load conditions
the filter drier cores must be replaced. Also if the moisture indicating sight glass shows a wet system
condition after 24 hours of operation the filter cores must be changed. This should remove any
contaminants introduced during field piping. The filter drier cores must also be changed anytime the
system is opened for servicing.

Table 17, Filter Drier Pressure Drop

Percent Circuit

Loading (%)

100 10 (69.0)

75 8 (55.2)
50 5 (34.5)
25 4 (27.6)

Maximum Recommended Pressure Drop Across Filter Drier

psig (kPa)

Refrigerant and Oil Charge

The relative position of the ALS unit and the evaporator and the distance between them plays a
critical role in determining suction and liquid line sizes and the field refrigerant and oil charges. ALS
units with the remote evaporator option are shipped with a factory refrigerant and oil charge suitable
for the normal packaged unit. It will be necessary to add refrigerant and oil for the added connecting
piping to the remote evaporator. See Table 18 for refrigerant charge for suction and liquid-vapor lines.
McQuayService will supply and add the additional oil required by the refrigerant piping. The correct
oil is Planetelf ACD68AW, McQuay Part No. 735030439 (5 gal.), 735030438 (1 gal.).

Charging Procedure

The calculated refrigerant and oil charge must be added through the factory supplied charging valve
located on the liquid-vapor line coming out of the compressor. Sufficient charge must be added to
clear the liquid line sight glass located at the outlet of the condenser. Add an extra 10 lb. of refrigerant
after the sight glass is clear.

Note: Charge must never be added through the compressor suction line.

20 IOMM ALS-1

Table 18, Refrigerant Charge for Suction and Liquid-Vapor Lines

Lineal Tubing

Length

Ft (m)

10 (3) 2 5/8 0.51 (0.23) 1 5/8 5.0 (2.3)

20 (6) 2 5/8 1.02 (0.46) 1 5/8 10.0 (4.5)

30 (9) 2 5/8 1.53 (0.69) 1 5/8 15.0 (6.8)

40 (12) 2 5/8 2.04 (0.92) 1 5/8 20.0 (9.0)

Suction Line Refrigerant Charge

lb (kg)

Line (in.) R-22 Line (in.) R-22

2 1/8 0.33 (0.15) 1 3/8 3.6 (1.6)

3 1/8 0.71 (0.32)
2 1/8 0.66 (0.30) 1 3/8 7.2 (3.3)

3 1/8 1.42 (0.64)
2 1/8 0.99 (0.45) 1 3/8 10.8 (4.9)

3 1/8 2.13 (0.96)
2 1/8 1.32 (0.60) 1 3/8 14.4 (6.5)

3 1/8 2.84 (1.29)

Liquid-Vapor Line Refrigerant Charge

lb (kg)

Oil Charge Calculation

Total Field Oil Charge = 4% by weight of the field refrigerant charge added to the suction and liquid­vapor lines.

Note: For every 10 lb. (160 oz) of refrigerant charge added, a 6.4 oz (equal to 0.4 pint fluid measure) oil
charge is required.

Example: (In I-P Units)

Total suction line lineal length = 20 ft.; Suction line size = 2 5/8 in.
Total liquid-vapor line lineal length = 30 ft.; Liquid-Vapor line size = 1 5/8

From Table 18 obtain the suction and liquid-vapor line refrigerant charge

Refrigerant charge required in the suction line = 1.0 lb.
Refrigerant charge required in the liquid-vapor line = 15.0 lb.
Total Refrigerant charge required in the suction and liquid-vapor line = 16.0 lb.

Total Oil Charge = 4% by weight of the total field refrigerant charge added to the suction and liquid­vapor lines = 10.3 oz (0.6 pint)

Notes:

1. The only approved oil is that identified on the label attached to the compressors. All POE oils are

hygroscopic and care should be exercised in handling the oil to avoid absorption and retention of
moisture.

2. Do not leave the oil container open for more than a minute while charging oil. Do not use oil that

has not been properly sealed and stored.

3. The evaporator is supplied without heater.

Dimensions

Use the ALS dimension drawings Figure 23 to Figure 27 for the ALS with remote evaporator. The
refrigerant connections are located approximately where the refrigerant connections to the unit
mounted evaporator are on a packaged chiller. The remote evaporator dimensions are Figure 18
through Figure 20.

IOMM ALS-1 21

Dimensions, Remote Evaporator

Figure 18, Evaporator for ALS 125 - ALS 204

ALS Model

Number

125 CDE-1410-1 103.80 (2637) 13.00 (330) 6.0 (152) 9.01 (229) 2 5/8 (67) 1 3/8 (35 0) 36.1 (136.6) 4.71 (.13)

155,170,175,185 CDE-1610-1 105.58 (2682) 13.00 (330) 6.0 (152) 8.12 (206) 2 5/8 (67) 1 3/8 (35 0) 45.6 (172.6) 6.37 (.18)

140 CDE-1610-2 105.58 (2682) 13.00 (330) 6.0 (152) 8.12 (206) 2 5/8 (67) 1 3/8 (35 0) 50.3 (190.4) 5.82 (.16)
195 CDE-1810-1 105.58 (2682) 14.00 (356) 6.0 (152) 8.12 (206) 2 5/8 (67) 1 3/8 (35 0) 58.4 (221.1) 8.16 (.23)
204 CDE-2010-1 103.70 (2634) 13.50 (343) 8.0 (203) 9.23 (234) 2 5/8 (67) 1 3/8 (35 0) 72.3 (273.7) 10.10 (.29)

CDE Model

Number

CDE-1410-1 128.31 (3259) 14.37 (365) 22.63 (575) 13.00 (330) 2.45 (62) 4.13 (105) 1.50 (38) 4.88 (124)
CDE-1610-1 128.31 (3259) 14.62 (371) 22.63 (575) 13.00 (330) 2.75 (70) 5.12 (130) 1.50 (38) 5.50 (140)
CDE-1610-2 128.31 (3259) 14.62 (371) 22.63 (575) 13.00 (330) 2.75 (70) 5.12 (130) 1.50 (38) 5.50 (140)
CDE-1810-1 129.32 (3285) 14.87 (378) 24.62 (625) 14.37 (365) 2.75 (70) 5.12 (130) 1.00 (25) 5.50 (140)
CDE-2010-1 128.81 (3272) 14.62 (371) 25.12 (638) 16.02 (407) 3.25 (83) 5.25 (133) 1.50 (38) 7.12 (181)

CDE Model

Number

CDE-1410-1 3.25 (83) 1.50 (38) 121.81 (3094) 123.81 (3145) 1.53 (39) 1.70 (43) 19.25 (489) 19.25 (489) 125 (32)
CDE-1610-1 3.25 (83) 1.50 (38) 121.81 (3094) 123.81 (3145) 1.53 (39) 1.70 (43) 19.25 (489) 19.25 (489) 125 (32)
CDE-1610-2 3.25 (83) 1.50 (38) 121.81 (3094) 123.81 (3145) 1.53 (39) 1.70 (43) 19.25 (489) 19.25 (489) 125 (32)
CDE-1810-1 3.25 (83) 2.50 (64) 121.81 (3094) 123.81 (3145) 1.53 (39) 1.70 (43) 21.25 (540) 21.25 (540) 125 (32)
CDE-2010-1 4.13 (105) 1.50 (38) 122.61 (3103) 124.58 (3164) 1.53 (39) 1.70 (43) 24.62 (625) 29.00 (737) 1.75 (44)

CDE Model

Number

CDE-1410-1 60.91 (1547) 13.00 (330) 8.00 (203) 10.3 (4.7) 10.3 (4.7) 1845 (837) 1790 (812)
CDE-1610-1 60.91 (1547) 13.00 (330) 8.00 (203) 13.9 (6.3) 13.9 (6.3) 2285 (1036) 2145 (973)
CDE-1610-2 60.91 (1547) 13.00 (330) 8.00 (203) 12.7 (5.8) 12.7 (5.8) 2285 (1036) 2110 (957)
CDE-1810-1 60.91 (1547) 14.00 (356) 8.00 (203) 17.8 (8.1) 17.8 (801) 2750 (1247) 2475 (1123)
CDE-2010-1 61.08 (1551) 13.50 (343) 13.50 (343) 22.8 (10.3) 22.8 (10.3) 3158 (1432) 2819 (1279)

CDE Model

Number

A D E F G H I J

K O R S U V W CC DD

Center of Gravity - Inches (mm) Operating Charge - Lbs. (kgs) R-22 Unit Weights - Lbs. (kgs)

X Y Z System #1 System #2 Operating Shipping

Water Connection - Inches (mm) Refrigerant Connection

C L P T M N

Dimensional Data - Inches (mm)

Dimensional Data - Inches (mm)

Water Volume

Gallons(Litre)

Refrig. Volume

Cu.Ft. (cu.mm)

22 IOMM ALS-1

Figure 19, Evaporator for ALS 205 - ALS 280

Cu.Ft. (cu. mm)

System #2

System #3

Number

250, 265, 280 CDE-2010-1 72.3 (274) 10.1 (0.29) 15.2 (6.9) 15.2 (6.9) 15.2 (6.9) 3165 (1435) 2825 (1281)
205, 220, 235 CDE-2010-2 80.9 (306) 9.4 (0.26) 14.0 (6.4) 14.0 (6.4) 14.0 (6.4) 3165 (1435) 2775 (1258)

CDE Model

Number

Water Volume

Refrig. Volume

Cu. Ft. (cu. mm)

Operating Charge - Lbs. (kgs) Unit Weights - Lbs. (kgs)ALS Model

System #1

Operating Shipping

IOMM ALS-1 23

Figure 20, Evaporator for ALS 300 - ALS 425

5.25 (133)

9.38 (238)

5.25 (133)

9.38 (238)

5.25 (133)

9.38 (238)

122.73 (3117)

122.73 (3117)

146.73 (3727)

Cu. Feet (Cu. M)

Number

330,340,360,370,380 CDE-2410-1 103.70 (2634) 7.68 (195) 2.30 (58) 6.66 (169) 2.22 (56)

300,315 CDE-2410-2 103.70 (2634) 7.68 (195) 2.30 (58) 6.66 (169) 2.22 (56)

425 CDE-2412-1 125.28 (3182) 7.68 (195) 2.30 (58) 6.66 (169) 2.22 (56)

Number

CDE-2410-1 7.12 (181) 1.53 (39) 4.13 (105)
CDE-2410-2 7.12 (181) 1.53 (39) 4.13 (105)
CDE-2412-1 7.12 (181) 1.53 (39) 4.13 (105)

Number

CDE-2410-1 13.50 (343) 18.00 (457) 61.37 (1559) 107 (405) 13.5 (0.38) 4250# (1927) 3700# (1678)
CDE-2410-2 13.50 (343) 18.00 (457) 61.37 (1559) 112 (424) 12.8 (0.36) 4290# (1946) 3640# (1651)
CDE-2412-1 13.50 (343) 18.00 (457) 73.37 (1863) 128 (485) 15.5 (0.44) 5100# (2313) 4400# (1996)

CDE Model Operating Charge - Lbs. (kgs.) R-22

Number System #1 System #2 System #3 System #4
CDE-2410-1 15 (6.8) 15 (6.8) 15 (6.8) 15 (6.8)
CDE-2410-2 14 (6.4) 14 (6.4) 14 (6.4) 14 (6.4)
CDE-2412-1 20 (9.1) 20 (9.1) 20 (9.1) 20 (9.1)

CDE Model

Number

I J K L M N O

Center of Gravity - Inches (mm) Unit Weights - Lbs. (kgs)CDE Model

P Q R

A B C D E F G H

Dimensional Data - Inches (mm)CDE Model

Dimensional Data - Inches (mm)ALS Model

Water Volume
Gallons (Litre)

7.50 (191)

7.50 (191)

7.50 (191)

125.17 (3179) 129.05 (3278) 9.52 (242)

125.17 (3179) 129.05 (3278) 9.52 (242)

149.17 (3789) 153.05 (3887) 10.73 (273)

Refrig. Volume

Operating Shipping

24 IOMM ALS-1

Water Flow and Pressure Drop

Balance the chilled water flow through the evaporator. The flow rates must fall between the minimum
and maximum values shown in Table 19 and Table 20. Flow rates below the minimum values shown
will result in laminar flow that will reduce efficiency, cause erratic operation of the electronic expansion
valve and could cause low temperature cutouts. On the other hand flow rates exceeding the maximum
values shown can cause erosion on the evaporator water connections and tubes.

Measure the chilled water pressure drop through the evaporator at field installed pressure taps. It is
important not to include valve or strainer pressure drop in these readings.

Variable chilled water flow through the evaporator while the compressor(s) are operating is not
recommended. MicroTech control set points are based upon a constant flow and variable
temperature.

Table 19, ALS 070 - 100, and ALS 220 - 265 Min/Max Flow Rates

ALS UNIT

SIZE GPM LPS GPM LPS SIZE GPM LPS GPM LPS

070 102 6.5 272 17.2 220 335 21.2 893 56.4
080 122 7.7 324 20.5 235 356 22.5 950 60.0
090 139 8.8 369 23.4 250 376 23.8 1000 63.2
100 147 9.3 391 24.8 265 391 24.7 1043 66.0

MIN. FLOW

RATE

Figure 21, ALS 070 - 100, Evaporator Pressure Drop

MAX FLOW RATE

ALS UNIT

MIN. FLOW

RATE

MAX. FLOW

RATE

IOMM ALS-1 25

Table 20, ALS 125 – 205 and ALS 280 - 425 Min/Max Flow Rates

ALS UNIT

SIZE GPM LPS GPM LPS SIZE GPM LPS GPM LPS

125 186 11.8 497 31.4 280 408 25.8 1088 68.8
140 209 13.2 557 35.2 300 440 27.8 1173 74.1
155 231 14.6 617 39.0 315 459 29.0 1222 77.1
170 253 16.0 675 42.7 330 479 30.2 1276 80.6
175 256 16.2 683 43.2 340 493 31.1 1313 82.9
185 274 17.3 730 46.1 360 523 33.0 1395 88.1
195 284 18.0 767 48.5 370 540 34.1 1438 90.8
204 303 19.1 808 51.0 380 559 35.3 1490 94.1
205 309 19.5 825 52.1 425 616 38.9 1650 104.2

MIN. FLOW

RATE

MAX FLOW RATE

ALS UNIT

MIN. FLOW

RATE

Figure 22, ALS 125 - 425, Evaporator Pressure Drop

MAX. FLOW

RATE

26 IOMM ALS-1

Physical Data

Table 21, ALS 070-100

DATA

BASIC DATA

Unit capacity @ ARI conditions, tons

(kW)

Unit operating charge R-22, lbs (kg) 150 (68) 160 (73) 180 (82) 190 (87)

Cabinet dimensions L x W x H, in.

(mm)

Unit operating weight, lbs. (kg) 5725 (2597) 6175 (2801) 6825 (3096) 7300 (3311)

Unit shipping weight, lbs. (kg) 5500 (2495) 5900 (2676) 6500 (2948) 6900 (3130)

COMPRESSORS, SCREW, SEMI-HERMETIC

Nominal tons, (kW0 65 (230) 80(280) 95 (335) 95 (335)

CONDENSERS, HIGH EFFICIENCY FIN & TUBE TYPE WITH INTEGRAL SUBCOOLER

Coil face area, sq. ft. (m2) 115.6 (10.7) 115.6 (10.7) 154.1 (14.3) 154.1 (14.3)

Finned height x finned length, in.

(mm)

Fins per inch x rows deep 16 x 3 16 x 3 16 x 3 16 x 3

CONDENSER FANS, DIRECT DRIVE PROPELLER TYPE

No. of fans - fan diameter, in. (mm) 6-28 (711) 6-28 (711) 8-28 (711) 8-28 (711)

No. of motors - hp (kW) 6-1.5 (1.1) 6-1.5 (1.1) 6-1.5 (1.1) 6-1.5 (1.1)

Fan & motor rpm, 60/50Hz 1140 1140 1140 1140

60 Hz fan tip speed, fpm

50 Hz fan tip speed, (m/sec)

60 Hz total unit airflow, cfm

50 Hz total unit airflow, (m2/sec

EVAPORATOR, DIRECT EXPANSION, BAFFLED SHELL & THRU TUBE

Shell diameter - tube length

in (mm) - ft. (mm)

Water volume, gallons (L) 24.3 (92.0) 32.6 (123.4) 41.3 (156.3) 43.6 (165)

Max. water pressure, psi (kPa) 175 (1207) 175 (1207) 175 (1207) 175 (1207)

Max. refrigerant pressure, psi (kPa) 225 (1552) 225 (1552) 225 (1552) 225 (1552)

070A 080A 090A 100A

68.1 (239) 77.9 (274) 90.6 (319) 96.4 (339)

124.7 X 83.4 X 92.5

(3167 X 2118 X 2350)

160 x 104

(4064 x 2642)

8357 8357 8357 8357

54120 54120 72160 72160

12-08

(305-2439)

124.7 X 83.4 X 92.5

(3167 X 2118 X 2350)

161 x 104

(4064 x 2642)

(356-2439)

ALS MODEL NUMBER

14008

159.4 X 83.4 X 92.5

(4049 X 2118 X 2350)

160 x 138.7)

4064 x 3523)

14-10

(356-3048)

159.4 X 83.4 X 92.5

(4049 X 2118 X 2350)

160 x 138.7)

4064 x 3523)

16-10

(407-3048)

Table 22, ALS 125-170

ALS MODEL NUMBER

DATA 125A 140A 155A 170A

BASIC DATA

Unit capacity @ ARI conditions, tons

(kW)

Unit operating charge R-22, lbs (kg) 140 (63.5) 140 (63.5) 140 (63.5) 150 (68.1) 150 (68.1) 150 (68.1) 150 (68.1) 160 (72.6)

Cabinet dimensions L x W x H, in.

(mm)

Unit operating weight, lbs. (kg) 9920 (4500) 10350 (4700) 10670 (4840) 10750 (4880)

Unit shipping weight, lbs. (kg) 9600 (4355) 9900 (4450) 10250 (4650) 10350 (4700)

COMPRESSORS, SCREW, SEMI-HERMETIC

Nominal tons, (kW0 65 (230) 65 (230) 65 (230) 80 (280) 80 (280) 80 (280) 80 (280) 95 (335)

CONDENSERS, HIGH EFFICIENCY FIN & TUBE TYPE WITH INTEGRAL SUBCOOLER

Coil face area, sq. ft. (m2) 115.6 (10.7) 115.6 (10.7) 115.6 (10.7) 115.6 (10.7) 115.6 (10.7) 115.6 (10.7) 115.6 (10.7) 115.6 (10.7)

Finned height x finned length, in.

(mm)

Fins per inch x rows deep 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3

CONDENSER FANS, DIRECT DRIVE PROPELLER TYPE

No. of fans - fan diameter, in. (mm) 10 - 28 (711) 10 - 28 (711) 12 - 28 (711) 12 - 28 (711)

No. of motors - hp (kW) 10 - 1.5 (1.1) 10 - 1.5 (1.1) 12 - 1.5 (1.1) 12 - 1.5 (1.1)

Fan & motor rpm, 60/50Hz 1140/950 1140/950 1140/950 1140/950

60 Hz fan tip speed, fpm

50 Hz fan tip speed, (m/sec)

60 Hz total unit airflow, cfm

50 Hz total unit airflow, (m2/sec

EVAPORATOR, DIRECT EXPANSION, BAFFLED SHELL & THRU TUBE

Shell diameter - tube length

in (mm) - ft. (mm)

CKT.1 CKT.2 CKT.1 CKT.2 CKT.1 CKT.2 CKT.1 CKT.2

62.2 (218) 62.2 (218) 64.4 (226) 75 (263) 77.1 (271) 77.1 (271) 79 (278) 89.7 (315)

228.7 x 83.4 x 92.5

(5809 x 2118 x 2350)

80 x 208

(2032 x 5283)

8357

(35.4)

90200

(35.5)

14 - 10

(356 - 3048)

80 x 208

(2032 x 5283)

228.7 x 83.4 x 92.5

(5809 x 2118 x 2350)

80 x 208

(2032 x 5283)

8357
(35.4)
90200
(35.5)

16 - 10

(406 - 3048)

80 x 208

(2032 x 5283)

228.7 x 83.4 x 92.5

(5809 x 2118 x 2350)

80 x 208

(2032 x 5283)

8357

(35.4)

108240

(42.6)

16 - 10

(406 - 3048)

80 x 208

(2032 x 5283)

228.7 x 83.4 x 92.5

(5809 x 2118 x 2350)

80 x 208

(2032 x 5283)

8357

(35.4)

108240

(42.6)

16 - 10

(406 - 3048)

80 x 208

(2032 x 5283)

IOMM ALS-1 27

Water volume, gallons (L) 36.1 (136.7) 45.6 (172.6) 45.6 (172.6) 45.6 (172.6)

Max. water pressure, psi (kPa) 175 (1207) 175 (1207) 175 (1207) 175 (1207)

Max. refrigerant pressure, psi (kPa) 225 (1552) 225 (1552) 225 (1552) 225 (1552)

Table 23, ALS 175-204

ALS MODEL NUMBER

DATA 175A 185A 195A 204A

Unit capacity @ ARI conditions,

tons (kW)

Unit operating charge R-22, lbs

(kg)

Cabinet dimensions

L x W x H, in. (mm)

Unit operating weight, lbs. (kg) 11250 (5100) 11250 (5100) 11500 (5218) 12570 (5701)

Unit shipping weight, lbs. (kg) 10850 (4920) 10850 (4920) 11100 (5036) 11980 (5433)

COMPRESSORS, SCREW, SEMI-HERMETIC

Nominal tons, (kW) 80 (280) 95 (335) 95 (335) 95 (335) 95 (335) 95 (335) 95 (335) 95 (335)

CONDENSERS, HIGH EFFICIENCY FIN & TUBE TYPE WITH INTEGRAL SUBCOOLER

Coil face area, sq. ft. (m2) 135.0 (12.5) 135.0 (12.5) 135.0 (12.5) 135.0 (12.5) 135.0 (12.5) 135.0 (12.5) 135.0 (12.5) 135.0

Finned height x finned length, in.

(mm)

Fins per inch x rows deep 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3 12 x 4 12 x 4

CONDENSER FANS, DIRECT DRIVE PROPELLER TYPE

No. of fans - fan diameter, in.

(mm)

No. of motors - hp (kW) 14 - 1.5 (1.1) 14 - 1.5 (1.1) 14 - 1.5 (1.1) 14 - 2.0 (1.5)

Fan & motor rpm, 60/50Hz 1140/950 1140/950 1140/950 1140/950

60 Hz fan tip speed, fpm

50 Hz fan tip speed, (m/sec)

60 Hz total unit airflow, cfm

50 Hz total unit airflow, (m2/sec

EVAPORATOR, DIRECT EXPANSION, BAFFLED SHELL & THRU TUBE

Shell diameter - tube length

in (mm) - ft. (mm)

Water volume, gallons (L) 43.6 (165.0) 43.6 (165.0) 57.3 (216.9) 69.6 (263.5)

Max. water pressure, psi (kPa) 175 (1207) 175 (1207) 175 (1207) 175 (1207)

Max. refrigerant pressure, psi

(kPa)

CKT.1 CKT.2 CKT.1 CKT.2 CKT.1 CKT.2 CKT.1 CKT.2

80.4 (282) 90.6 (318) 91.2 (320) 91.2 (320) 94.6 (332) 94.6 (332) 101 (355) 101 (355)

160 (72.6) 160 (72.6) 160 (72.6) 160 (72.6) 170 (77.1) 170 (77.1) 195 (88.4) 195 (88.4)

263.4 x 83.4 x 92.5

(6690 x 2118 x 2350)

80 x 243

(2032 x

6172)

14 - 28 (711) 14 - 28 (711) 14 - 28 (711) 14 - 28 (711)

(406 - 3048)

80 x 243

(2032 x 6172)

8357

(35.4)

126280

(49.7)

16 - 10

225 (1552) 225 (1552) 225 (1552) 225 (1552)

263.4 x 83.4 x 92.5

(6690 x 2118 x 2350)

80 x 243

(2032 x

6172)

8357

(35.4)

12680

(49.7)

16 - 10

(406 - 3048)

80 x 243

(2032 x

6172)

263.4 x 83.4 x 92.5

(6690 x 2118 x 2350)

80 x 243

(2032 x

6172)

8357

(35.4)

12680

(49.7)

18 - 10

(457 - 3048)

80 x 243

(2032 x

6172)

263.4 x 83.4 x 92.5

(6690 x 2118 x 2350)

80 x 243

(2032 x

6172)

8357

(35.4)

138908

(54.7)

20 - 10

(508 - 3048)

(12.5)

80 x 243

(2032 x

6172)

Table 24, ALS 205-235

ALS MODEL NUMBER

DATA 205A 220a 235A

Unit capacity @ ARI conditions,

tons (kW)

Unit operating charge R-22, lbs (kg) 140 (63.5) 140 (63.5) 150 (68.1) 140 (63.5) 150 (68.1) 150 (68.1) 150 (68.1) 150 (68.1) 150 (68.1)

Cabinet dimensions

L x W x H, in. (mm)

Unit operating weight, lbs. (kg) 15930 (7224) 15930 (7224) 15930 (7224)

Unit shipping weight, lbs. (kg) 15250 (6916) 15330 (6952) 15330 (6952)

COMPRESSORS, SCREW, SEMI-HERMETIC

Nominal tons, (kW0 65 (230) 65 (230) 80 (280) 65 (230) 80 (280) 80 (280) 80 (280) 80 (280) 80 (280)

CONDENSERS, HIGH EFFICIENCY FIN & TUBE TYPE WITH INTEGRAL SUBCOOLER

Coil face area, sq. ft. (m2) 115.6

Finned height x finned length, in.

(mm)

Fins per inch x rows deep 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3

CONDENSER FANS, DIRECT DRIVE PROPELLER TYPE

No. of fans - fan diameter, in. (mm) 16 - 28 (711) 16 - 28 (711) 18 - 28 (711)

No. of motors - hp (kW) 16 - 1.5 (1.1) 16 - 1.5 (1.1) 18 - 1.5 (1.1)

Fan & motor rpm, 60/50Hz 1140/950 1140/950 1140/950

60 Hz fan tip speed, fpm

50 Hz fan tip speed, (m/sec)

60 Hz total unit airflow, cfm 144320 144320 162360

CKT.1 CKT.2 CKT.3 CKT.1 CKT.2 CKT.3 CKT.1 CKT.2 CKT.3

64.4 (226) 66.1 (232) 75.8 (266) 66.1 (232) 78.2 (275) 79.0 (277) 79.3 (279) 79.3 (279) 79.0 (277)

(9017 x 2118 x 2400)

(10.7)

80 x 208

(2032 x

5283)

355 x 83.4 x 94.5

115.6

(10.7)

80 x 208

(2032 x

5283)

8357

(35.4)

115.6

(10.7)

160 x 104

(4064 x

2642)

80 x 208

355 x 83.4 x 94.5

(9017 x 2118 x 2400)

115.6

(10.7)

(2032 x

5283)

115.6

(10.7)

80 x 208

(2032 x

5283)

8357

(35.4)

115.6

(10.7)

160 x 104

(4064 x

2642)

(9017 x 2118 x 2400)

115.6

(10.7)

80 x 208

(2032 x

5283)

355 x 83.4 x 94.5

115.6

(10.7)

80 x 208

(2032 x

5283)

8357

(35.4)

115.6

(10.7)

160 x 104

(4064 x

2642)

28 IOMM ALS-1

50 Hz total unit airflow, (m2/sec (56.8) (56.8) (63.9)

EVAPORATOR, DIRECT EXPANSION, BAFFLED SHELL & THRU TUBE

Shell diameter - tube length

in (mm) - ft. (mm)

Water volume, gallons (L) 81 (306.6) 76 (287.7) 76 (287.7)

Max. water pressure, psi (kPa) 175 (1207) 175 (1207) 175 (1207)

Max. refrigerant pressure, psi (kPa) 225 (1552) 225 (1552) 225 (1552)

20 - 10

(508 - 3048)

20 - 10

(508 - 3048)

20 - 10

(508 - 3048)

Table 25, ALS 250-280

DATA

Unit capacity @ ARI conditions,

tons (kW)

Unit operating charge R-22, lbs (kg) 150 (68.1) 150 (68.1) 160 (72.6) 150 (68.1) 160 (72.6) 160 (72.6) 160 (72.6) 160 (72.6) 160 (72.6)

Cabinet dimensions

L x W x H, in. (mm)

Unit operating weight, lbs. (kg) 16200 (7347) 16200 (7347) 16250 (7370)

Unit shipping weight, lbs. (kg) 15600 (7075) 15600 (7075) 15650 (7098)

COMPRESSORS, SCREW, SEMI-HERMETIC

Nominal tons, (kW0 80 (280) 80 (280) 95 (335) 80 (280) 95 (335) 95 (335) 95 (335) 95 (335) 95 (335)

CONDENSERS, HIGH EFFICIENCY FIN & TUBE TYPE WITH INTEGRAL SUBCOOLER

Coil face area, sq. ft. (m2) 115.6

Finned height x finned length, in.

(mm)

Fins per inch x rows deep 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3 16 x 3

CONDENSER FANS, DIRECT DRIVE PROPELLER TYPE

No. of fans - fan diameter, in. (mm) 18 - 28 (711) 18 - 28 (711) 18 - 28 (711)

No. of motors - hp (kW) 18 - 1.5 (1.1) 18 - 1.5 (1.1) 18 - 1.5 (1.1)

Fan & motor rpm, 60/50Hz 1140/950 1140/950 1140/950

60 Hz fan tip speed, fpm

50 Hz fan tip speed, (m/sec)

60 Hz total unit airflow, cfm

50 Hz total unit airflow, (m2/sec

EVAPORATOR, DIRECT EXPANSION, BAFFLED SHELL & THRU TUBE

Shell diameter - tube length

in (mm) - ft. (mm)

Water volume, gallons (L) 69.6 (263.5) 69.6 (263.5) 69.6 (263.5)

Max. water pressure, psi (kPa) 175 (1207) 175 (1207) 175 (1207)

Max. refrigerant pressure, psi (kPa) 225 (1552) 225 (1552) 225 (1552)

CKT.1 CKT.2 CKT.3 CKT.1 CKT.2 CKT.3 CKT.1 CKT.2 CKT.3

80.2 (282) 79.0 (277) 91 (320) 80.2 (282) 89.7 (315) 91 (320) 91.4 (321) 89.7 (315) 91 (320)

(10.7)

80 x 208

(2032 x

5283)

250A 265A 280A

355 x 83.4 x 94.5

(9017 x 2118 x 2400)

115.6

(10.7)

80 x 208

(2032 x

5283)

8357

(35.4)

162360

(63.9)

20 - 10

(508 - 3048)

115.6

(10.7)

160 x 104

(4064 x

5283)

80 x 208

355 x 83.4 x 94.5

(9017 x 2118 x 2400)

115.6

(10.7)

(2032 x

5283)

115.6

(10.7)

80 x 208

(2032 x

5283)

8357

(35.4)

162360

(63.9)

20 - 10

(508 - 3048)

115.6

(10.7)

160 x 104

(4064 x

5283)

115.6

(10.7)

80 x 208

(2032 x

5283)

355 x 83.4 x 94.5

(9017 x 2118 x 2400)

115.6

(10.7)

80 x 208

(2032 x

5283)

8357

(35.4)

162360

(63.9)

20 - 10

(508 - 3048)

115.6

(10.7)

160 x 104

(4064 x

5283)

Table 26, ALS 300-340

DATA

Unit capacity @ ARI conditions, tons

(kW)

Unit operating charge R-22, lbs (kg) 155

Cabinet dimensions

L x W x H, in. (mm)

Unit operating weight, lbs. (kg) 21250 (9637) 21250 (9637) 21320 (9669) 21320 (9669)

Unit shipping weight, lbs. (kg) 20300 (9206) 20300 (9206) 20400 (9252) 20400 (9252)

COMPRESSORS, SCREW, SEMI-HERMETIC

Nominal tons, (kW0 65

CONDENSERS, HIGH EFFICIENCY FIN & TUBE TYPE WITH INTEGRAL SUBCOOLER

Coil face area, sq. ft. (m2) 96.3

Finned height x finned length, in. (mm) 80 x

Fins per inch x rows deep 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4

CONDENSER FANS, DIRECT DRIVE PROPELLER TYPE

No. of fans - fan diameter, in. (mm) 20 - 28 (711) 20 - 28 (711) 20 - 28 (711) 20 - 28 (711)

CKT.1 CKT.2 CKT.3 CKT.4 CKT.1 CKT.2 CKT.3 CKT.4 CKT.1 CKT.2 CKT.3 CKT.4 CKT.1 CKT.2 CKT.3 CKT.4

66.9

(235)

(70.3)

(230)65(230)80(280)80(280)65(230)80(280)80(280)80(280)80(280)80(280)80(280)80(280)80(280)80(280)80(280)95(335)

(8.9)

173

(2032

x

4394)

IOMM ALS-1 29

300A 315A 330A 340A

66.9

79.7

79.7

66.9

79.7

79.7

79.7

79.2

79.7

80.3

(235)

(280)

155

160

(70.3)

96.3
(8.9)

80 x

173

(2032

x

4394)

(72.6)

96.3
(8.9)

80 x

173

(2032

x

4394)

389.7 x 83.4 x 94.5

(9898 x 2118 x 2400)

(280)

160

(72.6)

96.3
(8.9)

80 x

173

(2032

x

4394)

(235)

(280)

155

160

(70.3)

(72.6)

389.7 x 83.4 x 94.5

(9898 x 2118 x 2400)

96.3

96.3

(8.9)

(8.9)

80 x

80 x

173

173

(2032

(2032

x

4394)

x

4394)

(280)

160

(72.6)

96.3
(8.9)

80 x

173

(2032

x

4394)

(280)

160

(72.6)

96.3
(8.9)

80 x

173

(2032

x

4394)

(278)

(280)

160

160

(72.6)

(72.6)

389.7 x 83.4 x 94.5

(9898 x 2118 x 2400)

96.3

96.3

(8.9)

(8.9)

80 x

80 x

173

173

(2032

(2032

x

4394)

x

4394)

(282)

160

(72.6)

96.3
(8.9)

80 x

173

(2032

x

4394)

80.3

(282)

160

(72.6)

96.3
(8.9)

80 x

173

(2032

x

4394)

79.2

79.7

(278)

(280)

160

160

(72.6)

(72.6)

389.7 x 83.4 x 94.5

(9898 x 2118 x 2400)

96.3

96.3

(8.9)

(8.9)

80 x

80 x

173

173

(2032

(2032

x

4394)

x

4394)

80.3

(282)

160

(72.6)

96.3
(8.9)

80 x

173

(2032

4394)

89.4

(314)

170

(77.1)

96.3
(8.9)

80 x

173

(2032

x

x

4394)

No. of motors - hp (kW) 20 - 2.0 (1.5) 20 - 2.0 (1.5) 20 - 2.0 (1.5) 20 - 2.0 (1.5)

Fan & motor rpm, 60/50Hz 1140/950 1140/950 1140/950 1140/950

60 Hz fan tip speed, fpm

50 Hz fan tip speed, (m/sec)

60 Hz total unit airflow, cfm

50 Hz total unit airflow, (m2/sec

EVAPORATOR, DIRECT EXPANSION, BAFFLED SHELL & THRU TUBE

Shell diameter - tube length

in (mm) - ft. (mm)

Water volume, gallons (L) 112 (424) 112 (424) 107 (405.0) 107 (405.0)

Max. water pressure, psi (kPa) 175 (1207) 175 (1207) 175 (1207) 175 (1207)

8357

(35.4)

198440

(93.6)

24 - 10

(609 - 3048)

8357

(35.4)

198440

(93.6)

24 - 10

(609 - 3048)

8357

(35.4)

198440

(93.6)

24 - 10

(609 - 3048)

8357

(35.4)

198440

(93.6)

24 - 10

(609 - 3048)

Table 27, ALS 360-425

DATA

BASIC DATA
Unit capacity @ ARI conditions,

tons (kW)

Unit operating charge R-22, lbs

(kg)

Cabinet dimensions

L x W x H, in. (mm)

Unit operating weight, lbs. (kg) 22920 (10395) 22970 (10417) 23020 (10440) 23813 (10800)

Unit shipping weight, lbs. (kg) 22000 (9977) 22050 (10000) 22100 (10023) 22715 (10302)

COMPRESSORS, SCREW, SEMI-HERMETIC

Nominal tons, (kW0 80

CONDENSERS, HIGH EFFICIENCY FIN & TUBE TYPE WITH INTEGRAL SUBCOOLER

Coil face area, sq. ft. (m2) 115.6

Finned height x finned length,

in. (mm)

Fins per inch x rows deep 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4 12 x 4

CONDENSER FANS, DIRECT DRIVE PROPELLER TYPE

No. of fans - fan dia., in. (mm) 24 - 28 (711) 24 - 28 (711) 24 - 28 (711) 24 - 28 (711)

No. of motors - hp (kW) 24 - 2.0 (1.5) 24 - 2.0 (1.5) 24 - 2.0 (1.5) 24 - 2.5 (1.9)

Fan & motor rpm, 60/50Hz 1140/950 1140/950 1140/950 1140/950

60 Hz fan tip speed, fpm

50 Hz fan tip speed, (m/sec)

60 Hz total unit airflow, cfm

50 Hz total unit airflow, (m2/sec

EVAPORATOR, DIRECT EXPANSION, BAFFLED SHELL & THRU TUBE

Shell diameter - tube length

in (mm) - ft. (mm)

Water volume, gallons (L) 107 (405.0) 107 (405.0) 107 (405.0) 129 (488)

Max. water pressure, psi (kPa) 175 (1207) 175 (1207) 175 (1207) 175 (1207)

Max. refrigerant pressure, psi

(kPa)

CKT.1 CKT.2 CKT.3 CKT.4 CKT.1 CKT.2 CKT.3 CKT.4 CKT.1 CKT.2 CKT.3 CKT.4 CKT.1 CKT.2 CKT.3 CKT.4

80.9

(284)

175

(79.4)

(280)80(280)95(335)95(335)80(280)95(335)95(335)95(335)95(335)95(335)95(335)95(335)95(335)95(335)95(335)95(335)

(10.7)

80 x

208

(2032 x

5283)

360A 370A 380A 425A

80.9

93.4

93.4

80.9

91.8

93.4

93.4

92.3

92.3

93.4

93.4

(284)

(328)

(328)

(284)

(323)

(328)

(328)

(325)

(325)

175

180

180

175

180

180

180

(79.4)

(81.6)

(81.6)

(79.4)

(81.6)

115.6

(10.7)

80 x

208

(2032 x

5283)

8357

(35.4)

238128

(112.4)

24 - 10

((609 - 3048)

(81.6)

115.6

(10.7)

80 x

208

(2032 x

5283)

(2032 x

459 x 83.4 x 94.5

(11659 x 2118 x 2400)

115.6

115.6

(10.7)

80 x

208

(2032 x

5283)

115.6

(10.7)

80 x

208

(2032 x

5283)

(10.7)

80 x

208

(2032 x

5283)

8357

(35.4)

238128

(112.4)

24 - 10

((609 - 3048)

225 (1552) 225 (1552) 225 (1552) 225 (1552)

459 x 83.4 x 94.5

(11659 x 2118 x 2400)

115.6

(10.7)

80 x

208

(2032 x

5283)

(81.6)

115.6

(10.7)

80 x

208

5283)

180

(81.6)

459 x 83.4 x 94.5

(11659 x 2118 x 2400)

115.6

(10.7)

80 x

208

(2032 x

5283)

180

(81.6)

115.6

(10.7)

80 x

208

(2032 x

(2032 x

5283)

8357

(35.4)

238128

(112.4)

24 - 10

((609 - 3048)

(328)

180

(81.6)

115.6

(10.7)

80 x

208

5283)

(328)

180

(81.6)

115.6

(10.7)

80 x

208

(2032 x

5283)

100.3
(353)

190

(86.2)

459 x 83.4 x 94.5

(11659 x 2118 x 2400)

115.6

(10.7)

80 x

208

(2032 x

5283)

100.3
(353)

190

(86.2)

115.6

(10.7)

80 x

208

(2032 x

5283)

8357

(35.4)

257180

(121.4)

24 - 12

(609 - 3658)

100.3
(353)

190

(86.2)

115.6

(10.7)

80 x

208

(2032 x

5283)

100.3
(353)

190

(86.2)

115.6

(10.7)

80 x

208

(2032 x

5283)

Major Components

Table 28, ALS 070-425

UNIT SIZE

070 155 1208-1 100 M1-M5
080 167 1408-1 140 M1-M5
090 175 1410-1 170 M1-M5

100 175 1610-1 170 M1-M5
125A 155 155 - - 1410-1 100 100 - - M1-M5 M2-M6 - ­140A 155 167 - - 1610-1 140 140 - - M1-M5 M2-M6
155A 167 167 - - 1610-1 140 140 - - M1-M5 M2-M6
170A 167 175 - - 1610-1 170 170 - - M1-M5 M2-M6
175A 167 175 - - 1610-1 170 170 - - M1-M5 M2-M6
185A 175 175 - - 1610-1 170 170 - - M1-M5 M2-M6
195A 175 175 - - 1810-1 170 170 - - M1-M5 M2-M6

COMPRESSOR

IDENTIFICATION

30 IOMM ALS-1

EVAPORATOR

VESSEL SIZE

ELECTRONIC EXPANSION

VALVE SIZE

CONTACTOR DESIGNATION

FOR COMPRESSOR

204A 175 175 - - 2010-1 170 170 - - M1-M5 M2-M6
205A 155 155 167 - 2010-3 140 140 140 - M1-M5 M2-M6 M3-M7
220A 155 167 167 - 2010-2 140 140 140 - M1-M5 M2-M6 M3-M7
235A 167 167 167 - 2010-2 140 140 140 - M1-M5 M2-M6 M3-M7
250A 167 167 167 - 2010-1 140 140 140 - M1-M5 M2-M6 M3-M7
265A 167 175 175 - 2010-1 170 170 170 - M1-M5 M2-M6 M3-M7
280A 175 175 175 - 2010-1 170 170 170 - M1-M5 M2-M6 M3-M7
300A 155 155 167 167 2410-2 140 140 140 140 M1-M5 M2-M6 M3-M7 M4-M8
315A 155 167 167 167 2410-2 140 140 140 140 M1-M5 M2-M6 M3-M7 M4-M8
330A 167 167 167 167 2410-1 140 140 140 140 M1-M5 M2-M6 M3-M7 M4-M8
340A 167 167 167 175 2410-1 140 140 170 170 M1-M5 M2-M6 M3-M7 M4-M8
360A 167 167 175 175 2410-1 140 140 170 170 M1-M5 M2-M6 M3-M7 M4-M8
370A 167 175 175 175 2410-1 170 170 170 170 M1-M5 M2-M6 M3-M7 M4-M8
380A 175 175 175 175 2410-1 170 170 170 170 M1-M5 M2-M6 M3-M7 M4-M8
425A 175 175 175 175 2412-1 170 170 170 170 M1-M5 M2-M6 M3-M7 M4-M8

IOMM ALS-1 31

Compressor Staging

ALS 125-204 (Does not apply to ALS 070-100)

Table 29, Two Compressors Available

STAGE UP

1 - - 0% 1 25% 0% 12.5%
2 50% 0% 25.0% 2 50% 0% 25.0%
3 75% 0% 37.5% 3 75% 0% 37.5%
4 50% 50% 50.0% 4 50% 50% 50.0%
5 75% 50% 62.5% 5 75% 50% 62.5%
6 75% 75% 75.0% 6 75% 75% 75.0%
7 100% 75% 87.5% 7 100% 75% 87.5%
8 100% 100% 100.0% 8 100% 100% 100.0%

LEAD

COMPRESSOR

Table 30, One Compressor Available

STAGE UP

1 - - 0% 1 25% 0% 12.5%
2 50% 0% 25.0% 2 50% 0% 25.0%
3 75% 0% 37.5% 3 75% 0% 37.5%
4 50% 0% 50.0% 4 100% 0% 50.0%

LEAD

COMPRESSOR

ALS 205-280

LAG 1

COMPRESSOR

LAG 1

COMPRESSOR

UNIT

CAPACITY

UNIT

CAPACITY

STAGE DOWN

STAGE Down

LEAD

COMPRESSOR

LEAD

COMPRESSOR

LAG 1

COMPRESSOR

LAG 1

COMPRESSOR

UNIT

CAPACITY

UNIT

CAPACITY

Table 31, Three Compressors Available

STAGE

UP

1 - - - 0% 1 25% 0% 0% 8.3%
2 50% 0% 0% 16.7% 2 50% 0% 0% 16.7%
3 75% 0% 0% 25.0% 3 75% 0% 0% 25.0%
4 50% 50% 0% 33.3% 4 50% 50% 0% 33.3%
5 75% 50% 0% 41.7% 5 75% 50% 0% 41.7%
6 75% 75% 0% 50.0% 6 50% 50% 50% 50.0%
7 75% 50% 50% 58.3% 7 75% 50% 50% 58.3%
8 75% 75% 50% 66.7% 8 75% 75% 50% 66.7%

9 75% 75% 75% 75.0% 9 75% 75% 75% 75.0%
10 100% 75% 75% 83.3% 10 100% 75% 75% 83.3%
11 100% 100% 75% 91.6% 11 100% 100% 75% 91.6%
12 100% 100% 100% 100.0% 12 100% 100% 100% 100.0%

LEAD

COMP.

LAG 1

COMP.

LAG 2

COMP.

UNIT

CAPACITY

STAGE
DOWN

LEAD

COMP.

LAG 1

COMP.

LAG 2

COMP.

Table 32, Two compressors available

STAGE

UP

1 - - - 0% 1 25% 0% 0% 8.3%

2 50% 0% 0% 16.7% 2 50% 0% 0% 16.7%

3 75% 0% 0% 25.0% 3 75% 0% 0% 25.0%

4 50% 50% 0% 33.3% 4 50% 50% 0% 33.3%

5 75% 50% 0% 41.7% 5 75% 50% 0% 41.7%

6 75% 75% 0% 50.0% 6 75% 75% 0% 50.0%

7 100% 75% 0% 58.3% 7 100% 75% 0% 58.3%

8 100% 100% 0% 66.7% 8 100% 100% 0% 66.7%

LEAD

COMP.

LAG 1

COMP.

LAG 2

COMP.

UNIT

CAPACITY

STAGE
DOWN

LEAD

COMP.

LAG 1

COMP.

LAG 2

COMP.

Table 33, One Compressor Available

STAGE

UP

1 - - - 0% 1 25% 0% 0% 8.3%

2 50% 0% 0% 16.7% 2 50% 0% 0% 16.7%

3 75% 0% 0% 25.0% 3 75% 0% 0% 25.0%

4 100% 0% 0% 33.3% 4 100% 0% 0% 33.3%

LEAD

COMP.

LAG 1

COMP.

LAG 2

COMP.

UNIT

CAPACITY

STAGE
DOWN

LEAD

COMP.

LAG 1

COMP.

LAG 2

COMP.

UNIT

CAPACITY

UNIT

CAPACITY

UNIT

CAPACITY

32 IOMM ALS-1

ALS 300-425

STAGE UP

Table 34, Four Compressors Available

LEAD

COMP.
1 - - - - 0.0% 1 25% 0% 0% 0% 6.3%
2 50% 0% 0% 0% 12.5% 2 50% 0% 0% 0% 12.5%
3 75% 0% 0% 0% 18.8% 3 75% 0% 0% 0% 18.8%
4 50% 50% 0% 0% 25.0% 4 50% 50% 0% 0% 25.0%
5 75% 50% 0% 0% 31.3% 5 75% 50% 0% 0% 31.3%
6 75% 75% 0% 0% 37.5% 6 50% 50% 50% 0% 37.5%
7 75% 50% 50% 0% 43.8% 7 75% 50% 50% 0% 43.8%
8 75% 75% 50% 0% 50.0% 8 50% 50% 50% 50% 50.0%
9 75% 75% 75% 0% 56.3% 9 75% 50% 50% 50% 56.3%

10 75% 75% 50% 50% 62.5% 10 75% 75% 50% 50% 62.5%
11 75% 75% 75% 50% 68.8% 11 75% 75% 75% 50% 68.8%
12 75% 75% 75% 75% 75.0% 12 75% 75% 75% 75% 75.0%
13 100% 75% 75% 75% 81.3% 13 100% 75% 75% 75% 81.3%
14 100% 100% 75% 75% 87.5% 14 100% 100% 75% 75% 87.5%
15 100% 100% 100% 75% 93.8% 15 100% 100% 100% 75% 93.8%
16 100% 100% 100% 100% 100.0% 16 100% 100% 100% 100% 100.0%

LAG 1

COMP.

LAG 2

COMP.

LAG 3

COMP.

UNIT

CAPACITY

STAGE
DOWN

LEAD

COMP.

LAG 1

COMP.

LAG 2

COMP.

LAG 3

COMP.

Table 35, Three Compressors Available

STAGE

1 - - - - 0.0% 25% 0% 0% 0% 6.3%
2 50% 0% 0% 0% 12.5% 50% 0% 0% 0% 12.5%
3 75% 0% 0% 0% 18.8% 75% 0% 0% 0% 18.8%
4 50% 50% 0% 0% 25.0% 50% 50% 0% 0% 25.0%
5 75% 50% 0% 0% 31.3% 75% 50% 0% 0% 31.3%
6 75% 75% 0% 0% 37.5% 50% 50% 50% 0% 37.5%
7 75% 50% 50% 0% 43.8% 75% 50% 50% 0% 43.8%
8 75% 75% 50% 0% 50.0% 75% 75% 50% 0% 50.0%

9 75% 75% 75% 0% 56.3% 75% 75% 75% 0% 56.3%
10 100% 75% 75% 0% 62.5% 100% 75% 75% 0% 62.5%
11 100% 100% 75% 0% 68.8% 100% 100% 75% 0% 68.8%
12 100% 100% 100% 0% 75.0% 100% 100% 100% 0% 75.0%

LEAD

COMP.

LAG 1

COMP.

LAG 2

COMP.

LAG 3

COMP.

UNIT

CAPACITY

LEAD

COMP.

LAG 1

COMP.

LAG 2

COMP.

LAG 3

COMP.

UNIT

CAPACITY

UNIT

CAPACITY

Table 36, Two Compressors Available

STAGE

1 - - - - 0.0% 25% 0% 0% 0% 6.3%
2 50% 0% 0% 0% 12.5% 50% 0% 0% 0% 12.5%
3 75% 0% 0% 0% 18.8% 75% 0% 0% 0% 18.8%
4 50% 50% 0% 0% 25.0% 50% 50% 0% 0% 25.0%
5 75% 50% 0% 0% 31.3% 75% 50% 0% 0% 31.3%
6 75% 75% 0% 0% 37.5% 75% 75% 0% 0% 37.5%
7 100% 75% 0% 0% 43.8% 100% 75% 0% 0% 43.8%
8 100% 100% 0% 0% 50.0% 100% 100% 0% 0% 50.0%

LEAD

COMP.

LAG 1

COMP.

LAG 2

COMP.

LAG 3

COMP.

UNIT

CAPACITY

LEAD

COMP.

LAG 1

COMP.

LAG 2

COMP.

LAG 3

COMP.

Table 37, One Compressors Available

STAGE

1 - - - - 0.0% 25% 0% 0% 0% 6.3%
2 50% 0% 0% 0% 12.5% 50% 0% 0% 0% 12.5%
3 75% 0% 0% 0% 18.8% 75% 0% 0% 0% 18.8%
4 100% 0% 0% 0% 25.0% 100% 0% 0% 0% 25.0%

LEAD

COMP.

LAG 1

COMP.

LAG 2

COMP.

LAG 3

COMP.

UNIT

CAPACITY

LEAD

COMP.

LAG 1

COMP.

LAG 2

COMP.

LAG 3

COMP.

UNIT

CAPACITY

UNIT

CAPACITY

IOMM ALS-1 33

Dimensional Data

Figure 23, ALS 070A-100A

UNIt
SIZE

070A 124.7 (3167) 93.7 (2380) 9.9 (252) 15.0 (381) 15.9 (404) 52.9 (1344) 39.0 (991) 5725 (2597) 5500 (2495) 850 (387)
080A 124.7 (3167 93.7 (2380) 9.9 (252) 15.0 (381) 19.5 (495) 52.9 (1344) 39.0 (991) 6175 (2801) 5900 (2676) 850 (387)
090A 159.4 (4049) 128.4 (3261) 20.6 (524) 15.0 (381) 19.5 (495) 64.9 (1649) 39.0 (991) 6825 (3096) 6500 (2948) 1150 (523)
100A 159.4 (4049) 128.4 (3261) 20.6 (524) 15.0 (381) 19.5 (495) 64.9 (1649) 39.0 (991) 7300 (3311) 6900 (3130) 1150 (523)

ALS

UNIT

SIZE Qty. Nom. Tons Qty. H.P. System #1 L1 L2 S1 S2 S3
070A 1 65 6 1.5 150 (68) 18.6 (473) 107.9 (2740) 13.0 (330) N/A 110.4 (2805)
080A 1 80 6 1.5 160 (73) 18.6 (473) 107.9 (2740) 13.0 (330) N/A 110.4 (2805)
090A 1 95 8 1.5 180 (82) 18.6 (473) 131.9 (3350) 13.0 (330) 95.0 (2416) 146.9 (3731)
100A 1 95 8 1.5 190 (87) 18.6 (473) 131.9 (3350) 13.0 (330) 95.0 (2416) 146.9 (3731)

LENGTH

A

COMPRESSOR FANS

B C D E X Y OPERATING SHIPPING

EVAPORATOR CENTER OF GRAVITY UNIT WEIGHTS lb (kg)ALS

REFRIGERANT

CHARGE lb (kg)

LIFTING HOLES ISOLATOR MOUNTING

COPPER
FIN ADD

34 IOMM ALS-1

Figure 24, ALS 125A-204A

ALS
UNIT
SIZE

125A 228.7 (5809) 117.6 (2987) 13.8 (351) 28.7 (729) 19.4 (493) 104.3 (2649) 41.7 (1059) 9920 (4500) 9600 (4355) 1652 (750)
140A 228.7 (5809) 118.5 (3010) 12.9 (328) 28.7 (729) 19.4 (493) 104.3 (2649) 41.7 (1059) 10350 (4700) 9900 (4355) 1652 (750)
155A 228.7 (5809) 118.5 (3010) 12.9 (328) 28.7 (729) 19.4 (493) 105.2 (2672) 41.7 (1059) 10670 (4840) 10250 (4650) 1652 (750)
170A 228.7 (5809) 118.5 (3010) 12.9 (328) 28.7 (729) 19.4 (493) 105.2 (2672) 41.7 (1059) 10750 (4880) 10350 (4700) 1652 (750)
175A 263.4 (6690) 153.2 (3891) 47.6 (1209) 28.7 (729) 19.4 (493) 113.1 (2873) 41.7 (1059) 11250 (5100) 10850 (4920) 1930 (876)
185A 263.4 (6690) 153.2 (3891) 47.6 (1209) 28.7 (729) 19.4 (493) 113.1 (2873) 41.7 (1059) 11250 (5100) 10850 (4920) 1930 (876)
195A 263.4 (6690) 153.2 (3891) 47.6 (1209) 27.3 (693) 20.4 (518) 115.2 (2926) 41.7 (1059) 11500 (5218) 11100 (5036) 1930 (876)
204A 263.4 (6690) 152.2 (3866) 48.5 (1232) 25.7 (653) 20.2 (513) 116.5 (2959) 41.7 (1059) 12570 (5701) 11980 (5433) 2025 (918)

UNIT

SIZE

125A 2 65/65 10 1.5 140 (63.5) 140 (63.5)

140A 2 65/80 10 1.5 140 (63.5) 150 (68.1)

155A 2 80/80 12 1.5 150 (68.1) 150 (68.1)

170A 2 80/95 12 1.5 150 (68.1) 160 (72.6)

175A 2 80/95 14 1.5 160 (72.6) 160 (72.6)

185A 2 95/95 14 1.5 160 (72.6) 160 (72.6)

195A 2 95/95 14 1.5 170 (77.1) 170 (77.1)

204A 2 95/95 14 2.0 195 (88.5) 195 (88.5)

ALS

LENGTH

A

COMPRESSOR FANS

QTY. NOM. TONS QTY. H.P. SYSTEM #1 SYSTEM #2

B C D E X Y OPERATING SHIPPING FOR COPPER FINS

EVAPORATOR CENTER OF GRAVITY

OPERATING REFRIGERANT

CHARGE (R-22) lb (kg))

UNIT WEIGHTS lb (kg)

STANDARD UNIT ADD’L WT.

IOMM ALS-1 35

Figure 25, ALS 205A-280A

ALS

CENTER OF GRAVITY UNIT WEIGHTS lb (kg)

UNIT

SIZE X Y OPERATING SHIPPING
205A 146.7 3,726 41.7 1,059 15,930 7,224 15,250 6,916 2,478 1,124 3 65/65/80 16 1.5 140 63.5 140 63.5 150 68.1
220A 146.7 3,726 41.7 1,059 15,980 7,247 15,330 6,952 2,478 1,124 3 65/80/80 16 1.5 140 63.5 150 68.1 150 68.1
235A 146.7 3,726 41.7 1,059 16,180 7,338 15,630 7,043 2,478 1,124 3 80/80/80 18 1.5 150 68.1 150 68.1 150 68.1
250A 146.7 3,726 41.7 1,059 16,200 7,347 15,530 7,075 2,478 1,124 3 80/80/95 18 1.5 150 68.1 150 68.1 160 72.6
265A 146.7 3,726 41.7 1,059 16,200 7,347 15,600 7,075 2,478 1,124 3 80/95/95 18 1.5 150 68.1 160 72.6 160 72.6
280A 146.7 3,726 41.7 1,059 16,250 7,370 15,650 7,098 2,478 1,124 3 95/95/95 18 1.5 160 72.6 160 72.6 160 72.6

ADD’L WEIGHT

FOR COPPER

FIN COILS

COMPRESORS FANS

OPERATING REFREGERANT

CHARGE (R-22) lb (kg)

SYSTEM #1 SYSTEM #2 SYSTEM #3

36 IOMM ALS-1

Figure 26, ALS 300-340

ALS

CENTER OF GRAVITY UNIT WEIGHTS lb (kg) COMPRESSORS FANS REFRIGERANT CHARGE (R-22) lb (kg)

UNIT
SIZE

300A 166.9 4239 41.7 1059 21,250 9637 20,300 9206 3,671 1665 4 65/65/80/80 20 2.0 155 70.3 155 70.3 160 72.6 160 72.6
315A 166.9 4239 41.7 1059 21,250 9637 20,300 9206 3,671 1665 4 65/80/80/80 20 2.0 155 70.3 160 72.6 160 72.6 160 72.6
330A 166.9 4239 41.7 1059 21,320 9669 20,400 9252 3,671 1665 4 80/80/80/80 20 2.0 160 72.6 160 72.6 160 72.6 160 72.6
340A 166.9 4239 41.7 1059 21,230 9669 20,400 9252 3,671 1665 4 80/80/80/95 20 2.0 160 72.6 160 72.6 160 72.6 170 77.1

X Y OPERATING SHIPPING

ADD’L WEIGHT

FOR COPPER

FIN COILS

QTY NOM.TONS QTY HP SYST. #1 SYST. #2 SYST. #3 SYST. #4

IOMM ALS-1 37

Figure 27, ALS 360-425

CENTER OF GRAVITY UNIT WEIGHTS lb (kg) COMPRESSORS FANS REFRIGERANT CHARGE (R-22) lb (kg)ALS
UNIT
SIZE

360A 185.0 4699 41.7 1059 22,920 10395 22,000 9977 4,406 1998 4 80/80/95/95 24 2.0 175 79.4 175 79.4 180 81.6 180 81.6
370A 185.0 4699 41.7 1059 22,970 10417 22,050 10000 4,406 1998 4 80/95/95/95 24 2.0 175 79.4 180 81.6 180 81.6 180 81.6
380A 185.0 4699 41.7 1059 23,020 10440 22,100 10023 4,406 1998 4 95/95/95/95 24 2.0 180 81.6 180 81.6 180 81.6 180 81.6
425A 192.4 4887 41.1 1044 23813 10800 22715 10302 4406 1998 4 95/95/95/95 24 2.5 190 86.2 190 86.2 190 86.2 190 86.2

X Y OPERATING SHIPPING

ADD’L WEIGHT

FOR COPPER

FIN COILS

NOM. SYST. #1 SYST. #2 SYST. #3 SYST. #4

38 IOMM ALS-1

Electrical Data

Field Wiring

General

Wiring must comply with all applicable codes and ordinances. Warranty is voided if wiring is not in
accordance with specifications. An open fuse indicates a short, ground, or overload. Before replacing
a fuse or restarting a compressor or fan motor, the trouble must be found and corrected.

Copper wire is required for all power lead terminations at the unit and copper must be used for all other
wiring to the unit.

ALS units may be ordered with main power wiring for either single or multiple point power connection.
If single point power connection is ordered, a single large power terminal block is provided and wiring
within the unit is sized in accordance with the National Electrical code. A single field supplied
disconnect is required. An optional factory mounted transformer for the 115 volt control circuit may
be provided.

If multiple point power wiring is ordered, two power connections (125 through 204 and 300 through

425) or three power connections (205 through 280) are required and wiring within the unit is sized in
accordance with the National Electrical Code. A separate circuit is required for the 115 volt control
circuit. Separate field supplied disconnects are required for each electrical circuit.

It may be desirable to have the unit evaporator heater on a separate disconnect switch from the main
unit power supply so that the unit may be shut down without defeating the freeze protection provided
by the cooler heater.

CAUTION

ALS unit compressors are single direction rotation compressors. For this reason proper phasing of
electrical power is important. Electrical phasing must be A, B, C for electrical phases 1, 2 and 3 (A=L1,
B=L2, C=L3). Units supplied with single point, factory power connections will include one
MotorSaver phase failure/phase reversal protective device that will prevent operation of the unit with
incorrect power phasing. The MotorSaver is factory wired and tested. Do not alter the wiring to the

MotorSaver.

Multiple point power wired units will include two (125 through 204) and (300 through 425) or three (205
through 280) MotorSaver safety controls (one for each power supply), and the contractor is cautioned
to not apply power until the phasing is verified with a phase sequence meter.

WARNING

Internal power wiring to the compressors for the single point versus the multiple point option are
different. It is imperative that the proper field wiring be installed according to the way the unit is built.

Overload Dial Setting

For units with 1 contactor and 1 overload per compressor: The Overload must be set at a "Must Hold
Dial Setting" equal to 125% of the compressor RLA listed on the unit data plate.

For units with 2 contactors and 2 overloads per compressor: The Overload must be set at a "Must
Hold Dial Setting" equal to 125% of half the compressor RLA listed on the unit data plate.

Note: The "Must Trip Amps" is 12% higher than the "Must Hold Dial Setting". The accuracy of the
Overload Setting is ±2%.

IOMM ALS-1 39

Wire Sizing Ampacities

Table 38, Single Point Connection, ALS 070-100

ALS

UNIT

SIZE

070A 380 60 185 3 3/0 1 2.0 250 300

080A 380 60 227 3 4/0 1 2.0 300 350

090A 380 60 262 3 300 1 2.5 350 450

100A 380 60 262 3 300 1 2.5 350 450

(*) Table based on 75°C field wire per NEC

VOLTS HZ

208 335 3 400 1 3.0 500 500
230 307 3 350 1 2.5 400 500

460 153 3 2/0 1 1.5 200 250
575 124 3 #1 1 1.5 175 200
208 410 3 600 1 3.0 500 700
230 375 3 500 1 3.0 500 600

460 187 3 3/0 1 1.5 250 300
575 150 3 1/0 1 1.5 200 250
208 475 3 350 2 2.5 600 800
230 434 3 300 2 2.5 600 700

460 216 3 4/0 1 2.0 300 350
575 173 3 2/0 1 1.5 225 250
208 475 3 350 2 2.5 600 800
230 434 3 300 2 2.5 600 700

460 216 3 4/0 1 2.0 300 350
575 173 3 2/0 1 1.5 225 250

MINIMUM

CIRCUIT

AMPACITY

(MCA)

FIELD WIRE HUB

QTY.

POWER SUPPLY FIELD FUSE SIZE

WIRE

GUAGE

QTY.

NOMINAL

SIZE

RECOM-

MENDED

MAXIMUM

40 IOMM ALS-1

Table 39, Single Point Connection, ALS 125-204

ALS

UNIT

SIZE

125A 460 273 3 300 1 2.5 300 350

140A 460 307 3 350 1 2.5 400 400

155A 460 340 3 500 1 3.0 400 450

170A 460 364 3 500 1 3.0 450 500

175A 460 369 3 500 1 3.0 450 500

185A 460 388 6 #3/0 2 2.0 450 500

195A 460 388 6 #3/0 2 2.0 450 500

204A 460 399 6 #3/0 2 2.0 500 500

(*) Field wire size values apply to 90°C rated wire per NEC

VOLTS HZ

208 598 6 350 2 2.5 700 800
230 548 6 300 2 2.5 600 700
380 60 331 3 400 1 3.0 400 450

575 221 3 4/0 1 2.0 250 300
208 673 6 500 2 3.0 800 800
230 616 6 350 2 2.5 700 800
380 60 372 3 500 1 3.0 450 500

575 247 3 250 1 2.5 300 350
208 745 6 500 2 3.0 800 1000
230 682 6 500 2 3.0 800 800
380 60 412 6 #4/0 2 2.0 500 500

575 273 3 300 1 2.5 300 350
208 799 6 600 2 3.0 1000 1000
230 730 6 500 2 3.0 800 1000
380 60 441 6 #4/0 2 2.0 500 600

575 292 3 350 1 2.5 350 400
208 810 6 600 2 3.0 1000 1000
230 741 6 500 2 3.0 1000 1000
380 60 448 6 250 2 2.5 500 600

575 296 3 350 1 2.5 350 400

208* 853* 6 600* 2 3.0 1000 1000

230 779 6 600 2 3.0 1000 1000
380 60 471 6 250 2 2.5 500 600

575 311 3 400 1 2.5 350 400

208* 853* 6 600* 2 3.0 1000 1000

230 779 6 600 2 3.0 1000 1000
380 60 471 6 250 2 2.5 500 600

575 311 3 400 1 2.5 350 400

208* 881* 6 600* 2 3.0 1000 1200

230 799 6 600 2 3.0 1000 1000
380 60 481 6 250 2 2.5 500 600

575 321 3 400 1 2.5 400 400

MINIMUM

CIRCUIT

AMPACITY

(MCA)

FIELD WIRE HUB

QTY.

POWER SUPPLY FIELD FUSE SIZE

WIRE

GUAGE

QTY.

NOMINAL

SIZE

RECOM-

MENDED

MAXIMUM

IOMM ALS-1 41

Table 40, Single Point Connection, ALS 205-425

ALS

UNIT

SIZE

205A 460 60 433 6 #4/0 2 2.0 500 500

220A 460 60 460 6 #4/0 2 2.0 500 500

235A 460 60 492 6 250 2 2.0 600 600

250A 460 60 516 6 300 2 2.0 600 600

265A 460 60 535 6 300 2 2.0 600 600

280A 460 60 554 6 300 2 2.0 600 700

300A 460 60 596 6 350 2 2.5 700 700

315A 460 60 623 6 400 2 2.5 700 700

330A 460 60 650 6 400 2 2.5 700 700

340A 460 60 674 6 500 2 3.0 800 800

360A 460 60 707 6 500 2 3.0 800 800

370A 460 60 726 6 500 2 3.0 800 800

380A 460 60 745 6 500 2 3.0 800 800

425A 460 60 770 6 600 2 3.0 800 800

Note: Table based on 75°C field wire except for 380V ALS 360, 370, and 425 which require 90°C field wire,

VOLTS HZ

380 525 6 300 2 2.0 600 600

575 349 2 #3/0 2 1.5 400 450
380 558 6 300 2 2.0 700 700

575 370 6 #3/0 2 1.5 450 450
380 597 6 350 2 2.5 700 700

575 395 6 #3/0 2 1.5 450 500
380 626 6 400 2 2.5 700 800

575 414 6 #4/0 2 2.0 500 500
380 649 6 400 2 2.5 800 800

575 429 6 #4/0 2 2.0 500 500
380 672 6 500 2 3.0 800 800

575 444 6 #4/0 2 2.0 500 500
380 723 6 500 2 3.0 800 800

575 481 6 250 2 2.0 500 500
380 756 6 500 2 3.0 800 800

575 502 6 250 2 2.0 600 600
380 789 6 600 2 3.0 800 800

575 523 6 300 2 2.0 600 600
380 818 6 600 2 3.0 1000 1000

575 542 6 300 2 2.0 600 600

380* 859 6 600 2 3.0 1000 1000

575 569 6 300 2 2.0 600 600

380* 882 6 600 2 3.0 1000 1000

575 584 6 350 2 2.5 700 700

380* 905 6 600 2 3.0 1000 1000

575 599 6 350 2 2.5 700 700

380* 931 6 600 2 3.0 1000 1000

575 619 6 350 2 2.5 700 700

MINIMUM

CIRCUIT

AMPACITY

(MCA)

FIELD WIRE HUB

QTY.

POWER SUPPLY FIELD FUSE SIZE

WIRE

GUAGE

QTY.

NOMINAL

SIZE

RECOM-

MENDED

MAXIMUM

42 IOMM ALS-1

Table 41, Multiple Point Connection, ALS 125-204

ELECTRICAL CIRCUIT #1 ELECTRICAL CIRCUIT #2

ALS

UNIT

VOLTS HZ

SIZE

208 329 3 400 1 3.0 400 500 329 3 400 1 3.0 400 500

125A 380 60 182 3 #3/0 1 2.0 225 300 182 3 #3/0 1 2.0 225 300

140A 380 60 182 3 #3/0 1 2.0 225 300 223 3 #4/0 1 2.0 300 350

155A 380 60 226 3 #4/0 1 2.0 300 350 226 3 #4/0 1 2.0 300 350

170A 380 60 226 3 #4/0 1 2.0 300 350 255 3 250 1 2.5 350 400

175A 380 60 230 3 #4/0 1 2.0 300 350 259 3 300 1 2.5 350 400

185A 380 60 259 3 300 1 2.5 350 400 259 3 300 1 2.5 350 400

195A 380 60 259 3 300 1 2.5 350 400 259 3 300 1 2.5 350 400

204A 380 60 284 3 300 1 2.5 400 450 264 3 300 1 2.5 400 450

230 301 3 350 1 2.5 400 500 301 3 350 1 2.5 400 500

460 150 3 #1/0 1 1.5 200 250 150 3 #1/0 1 1.5 200 250
575 122 3 #1 1 1.5 150 200 122 3 #1 1 1.5 150 200
208 329 3 400 1 3.0 400 500 404 6 #4/0 2 2.0 500 700
230 301 3 350 1 2.5 400 500 369 3 500 1 3.0 500 600

460 150 3 #1/0 1 1.5 200 250 184 3 #3/0 1 2.0 250 300
575 122 3 #1 1 1.5 150 200 148 3 #1/0 1 1.5 200 250
208 410 6 #4/0 2 2.0 500 700 410 6 #4/0 2 2.0 500 700
230 375 3 500 1 3.0 500 600 375 3 500 1 3.0 500 600

460 187 3 #3/0 1 2.0 250 300 187 3 #3/0 1 2.0 250 300
575 150 3 #1/0 1 1.5 200 250 150 3 #1/0 1 1.5 200 250
208 410 6 #4/0 2 2.0 500 700 464 6 250 2 2.5 600 800
230 375 3 500 1 3.0 500 600 423 6 #4/0 2 2.0 500 700

460 187 3 #3/0 1 2.0 250 300 211 3 #4/0 1 2.0 250 350
575 150 3 #1/0 1 1.5 200 250 169 3 #2/0 1 1.5 225 250
208 416 6 #4/0 2 2.0 500 700 470 6 250 2 2.5 600 800
230 381 6 #3/0 2 2.0 500 600 429 6 #4/0 2 2.0 500 700

460 190 3 #3/0 1 2.0 250 300 214 3 #4/0 1 2.0 250 350
575 152 3 #2/0 1 1.5 200 250 171 3 #2/0 1 1.5 225 250
208 470 6 250 2 2.5 600 800 470 6 250 1 2.5 600 800
230 429 6 #4/0 2 2.0 500 700 429 6 #4/0 1 2.0 500 700

460 214 3 #4/0 1 2.0 250 350 214 3 #4/0 1 2.0 250 350
575 171 3 #2/0 1 1.5 225 250 171 3 #2/0 1 1.5 225 250
208 470 6 250 2 2.5 600 800 470 6 250 1 2.5 600 800
230 429 6 #4/0 2 2.0 500 700 429 6 #4/0 1 2.0 500 700

460 214 3 #4/0 1 2.0 250 350 214 3 #4/0 1 2.0 250 350
575 171 3 #2/0 1 1.5 225 250 171 3 #2/0 1 1.5 225 250
208 484 6 250 2 2.5 700 800 484 6 250 2 2.5 700 800
230 439 6 #4/0 2 2.0 600 700 439 6 #4/0 2 2.0 600 700

460 219 3 #4/0 1 2.0 300 350 219 3 #4/0 1 2.0 300 350
575 176 3 #3/0 1 2.0 250 300 176 3 #3/0 1 2.0 250 300

MINIMUM

CIRCUIT

AMPS
(MCA)

POWER SUPPLY FIELD FUSING POWER SUPPLY FIELD FUSING

FIELD WIRE HUB FIELD WIRE HUB

WIRE

QTY

GAUGE

QTY

HUB
SIZE

REC
Fuse
SIZE

FUSE

MAX

SIZE

MINIMUM

CIRCUIT

AMPS
(MCA)

QTY

WIRE

GAUGE

QTY

HUB
SIZE

REC

FUSE

SIZE

MAX

FUSE

SIZE

IOMM ALS-1 43

Table 42, Multiple Point Connection, ALS 205-280, (Circuit #3 continued on next page)

ELECTRICAL CIRCUIT #1 ELECTRICAL CIRCUIT #2

ALS

UNIT

VOLTS HZ

SIZE

208 329 3 400 1 2.5 400 500 329 3 400 1 2.5 400 500

205A 380 60 182 3 #3/0 1 1.5 250 300 182 3 #3/0 1 1.5 250 300

220A 380 60 182 3 #3/0 1 1.5 250 300 223 3 #4/0 1 2 300 350

235A 380 60 227 3 #4/0 1 2 300 350 227 3 #4/0 1 2 300 350

250A 380 60 227 3 #4/0 1 2 300 350 227 3 #4/0 1 2 300 350

265A 380 60 227 3 #4/0 1 2 300 350 256 3 250 1 2 350 400

280A 380 60 256 3 250 1 2 350 400 256 3 250 1 2 350 400

230 302 3 350 1 2.5 400 500 302 3 350 1 2.5 400 500

460 150 3 #1/0 1 1.25 200 250 150 3 #1/0 1 1.25 200 250
575 122 3 #1/0 1 1.25 175 200 122 3 #1/0 1 1.25 175 200
208 329 3 400 1 2.5 400 500 410 6 300 1 3 600 700
230 302 3 350 1 2.5 400 500 375 6 250 1 3 500 600

460 150 3 #1/0 1 1.25 200 250 187 3 #3/0 1 1.5 250 300
575 122 3 #1/0 1 1.25 175 200 150 3 #1/0 1 1.25 200 250
208 410 6 300 1 3 600 700 410 6 300 1 3 600 700
230 375 6 250 1 3 500 600 375 6 250 1 3 500 600

460 184 3 #3/0 1 1.5 250 300 187 3 #3/0 1 1.5 250 300
575 150 3 #1/0 1 1.25 200 250 150 3 #1/0 1 1.25 200 250
208 410 6 300 1 3 600 700 410 6 300 1 3 600 700
230 375 3 250 1 3 500 600 375 6 250 1 3 500 600

460 187 3 #3/0 1 1.5 250 300 187 3 #3/0 1 1.5 250 300
575 150 3 #1/0 1 1.25 200 250 150 3 #1/0 1 1.25 200 250
208 410 6 300 1 3 600 700 464 6 350 1 3.5 700 800
230 375 6 250 1 3 500 600 423 6 300 1 3 600 700

460 187 3 #3/0 1 1.5 250 300 211 3 #4/0 1 2 300 350
575 150 3 #1/0 1 1.25 200 250 170 3 #2/0 1 1.5 250 250
208 464 6 350 1 3.5 700 800 464 6 350 1 3.5 700 800
230 423 6 300 1 3 600 700 423 6 300 1 3 600 700

460 211 3 #4/0 1 2 300 350 211 3 #4/0 1 2 300 350
575 170 3 #2/0 1 1.5 250 250 170 3 #2/0 1 1.5 250 250

MIN.

CIRCUIT

AMPS

(MCA)

POWER SUPPLY FIELD FUSING MIN. POWER SUPPLY FIELD FUSING

FIELD WIRE HUB REC MAX CIRCUIT FIELD WIRE HUB REC MAX

WIRE

QTY

GAUGE

QTY

FUSE FUSE AMPS FUSE FUSE

HUB
SIZE SIZE SIZE (MCA)

QTY

WIRE

GAUGE

HUB

QTY

SIZE SIZE SIZE

44 IOMM ALS-1

Table 42, Multiple Point Connection, ALS 205-280 (Continued)

ALS MINIMUM POWER SUPPLY FIELD

UNIT VOLTS HZ CIRCUIT FIELD WIRE HUB REC MAX

SIZE AMPS WIRE HUB FUSE FUSE

(MCA)
208 410 6 300 1 3.0 600 700
230 375 6 250 1 3.0 500 600

205A 380 60 227 3 #4/0 1 2.0 300 350

460 187 3 #3/0 1 1.5 250 300
575 150 3 #1/0 1 1.25 200 250
208 410 6 300 1 3.0 600 700
230 375 6 250 1 3.0 500 600

220A 380 60 227 3 #4/0 1 2.0 300 350

460 187 3 #3/0 1 1.5 250 300
575 150 3 #1/0 1 1.25 300 250
208 410 6 300 1 3.0 600 700
230 375 6 250 1 3.0 500 600

235A 380 60 227 3 #4/0 1 2.0 300 350

460 187 3 #3/0 1 1.5 250 300
575 150 3 #1/0 1 1.25 200 250
208 464 6 350 1 3.5 700 800
230 423 6 300 1 3.0 600 700

250A 380 60 256 3 250 1 2.0 350 400

460 211 3 #4/0 1 2.0 300 350
575 170 3 #2/0 1 1.5 250 250
208 464 6 350 1 3.5 700 800
230 423 6 300 1 3.0 600 700

265A 380 60 256 3 250 1 2.0 350 400

460 211 3 #4/0 1 2.0 300 350
575 170 3 #2/0 1 1.5 250 250
208 464 6 350 1 3.5 700 800
230 423 6 300 1 3.0 600 700

280A 380 60 256 3 250 1 2.0 350 400

460 211 3 #4/0 1 2.0 300 250
575 170 3 #2/0 1 1.5 250 250

ELECTRICAL CIRCUIT #3

QTY

GAUGE

QTY

SIZE SIZE SIZE

FUSING

IOMM ALS-1 45

Table 43, Multiple Point Connection, ALS 300-425

ALS MIN. POWER SUPPLY FIELD FUSING MIN. POWER SUPPLY FIELD FUSING

UNIT VOLTS HZ CIRCUIT FIELD WIRE HUB REC MAX CIRCUIT FIELD WIRE HUB REC MAX

SIZE AMPS WIRE HUB FUSE FUSE AMPS WIRE HUB FUSE FUSE

(MCA)
208 693 6 500 2 3.0 800 800 693 6 500 2 3.0 800 800
230 630 6 400 2 2.5 800 800 630 6 400 2 2.5 800 800

300A 380 60 382 6 250 1 3.0 450 500 382 6 250 1 3.0 450 500

460 315 3 400 1 2.5 400 450 315 3 400 1 2.5 400 450
575 254 3 250 1 2.0 350 350 254 3 250 1 2.0 350 350
208 693 6 500 2 3.0 800 800 753 6 500 2 3.0 1000 1000
230 630 6 400 2 2.5 800 800 684 6 400 2 3.0 800 800

315A 380 60 382 6 250 1 3.0 450 500 415 6 300 1 3.0 500 500

460 315 3 400 1 2.5 400 450 342 3 400 1 3.0 400 450
575 254 3 250 1 2.0 350 350 275 3 250 1 2.0 350 350
208 753 6 500 2 3.0 1000 1000 753 6 500 2 3.0 1000 1000
230 684 6 500 2 3.0 800 800 684 6 500 2 3.0 800 800

330A 380 60 415 6 300 1 3.0 500 500 415 6 300 1 3.0 500 500

460 342 3 500 1 3.0 400 450 342 3 500 1 3.0 400 450
575 275 3 300 1 2.0 350 350 275 3 300 1 2.0 350 350
208 753 6 500 2 3.0 1000 1000 807 6 600 2 3.0 1000 1000
230 684 6 500 2 3.0 800 800 732 6 500 2 3.0 1000 1000

340A 380 60 415 6 300 1 3.0 500 500 444 6 300 1 3.0 500 600

460 342 3 500 1 3.0 400 450 366 3 500 1 3.0 450 500
575 275 3 300 1 2.0 350 350 294 3 350 1 2.5 350 400
208 822 6 600 2 3.0 1000 1000 822 6 600 2 3.0 1000 1000
230 746 6 500 2 3.0 1000 1000 746 6 500 2 3.0 1000 1000

360A 380 60 453 6 300 1 3.0 500 600 453 6 300 1 3.0 500 600

460 373 3 500 1 3.0 450 500 373 3 500 1 3.0 450 500
575 300 3 350 1 2.5 400 400 300 3 350 1 2.5 400 400

208* 822 6 600 2 3.0 1000 1000 865 6 600 2 3.0 1000 1000

230 746 6 500 2 3.0 1000 1000 784 6 600 2 3.0 1000 1000

370A 380 60 453 6 300 1 3.0 500 600 476 6 350 1 3.5 500 600

460 373 3 500 1 3.0 450 500 392 3 600 1 3.0 450 500
575 300 3 350 1 2.5 400 400 315 3 400 1 2.5 400 400

208* 865 6 600 2 3.0 1000 1000 865 6 600 2 3.0 1000 1000

230 784 6 600 2 3.0 1000 1000 784 6 600 2 3.0 1000 1000

380A 380 60 476 6 350 1 3.5 500 600 476 6 350 1 3.5 500 600

460 392 3 600 1 3.0 450 500 392 3 600 1 3.0 450 500
575 315 3 400 1 2.5 400 400 315 3 400 1 2.5 400 400

208* 892 6 600 2 3.0 1200 1200 892 6 1200 2 3.0 1200 1200

230 808 6 600 2 3.0 1000 1000 808 6 1000 2 3.0 1000 1000

425A 380 60 489 6 350 1 3.0 500 600 489 6 600 1 3.0 600 600

460 404 3 600 1 3.0 500 500 404 3 500 1 3.0 500 500
575 325 3 400 1 2.5 400 400 325 3 400 1 2.5 400 400

Note: Table based on 75°C field wire except 208V ALS 370 and 380 which require 90°C field wire

ELECTRICAL CIRCUIT #1 & 3 ELECTRICAL CIRCUIT #2 & 4

QTY

GAUGE

QTY

SIZE SIZE SIZE (MCA)

QTY

GAUGE

QTY

SIZE SIZE SIZE

46 IOMM ALS-1

Compressor and Condenser Fan Motors

Table 44, Amp Draw, ALS 070-100

ALS

UNIT

SIZE

070A 380 60 132 3.4 6 14.4 943 604

080A 380 60 165 3.4 6 14.4 943 604

090A 380 60 188 3.4 8 14.4 943 604

100A 380 60 188 3.4 8 14.4 943 604

VOLTS HZ

208 240 5.8 6 23.7 1459 934
230 218 5.8 6 21.4 1628 1042

460 109 2.8 6 10.7 764 489
575 88 2.3 6 11.5 589 377
208 300 5.8 6 23.7 1459 934
230 272 5.8 6 21.4 1628 1042

460 136 2.8 6 10.7 764 489
575 109 2.3 6 11.5 589 377
208 343 5.8 8 23.7 1459 934
230 310 2.8 8 21.4 1628 1042

460 155 2.8 8 10.7 764 489
575 124 2.3 8 11.5 589 377
208 343 5.8 8 23.7 1459 934
230 310 2.8 8 21.4 1628 1042

460 155 2.8 8 10.7 764 489
575 124 2.3 8 11.5 589 377

RATED LOAD AMPS LOCKED ROTOR AMPS

COMPRESSOR

FAN

MOTORS

FLA

(EACH)

NUMBER

OF

FAN

MOTORS

FAN

MOTORS

(EACH)

COMPRESSOR

ACROSS-THE-LINE REDUCED INRUSH

Table 45, Amp Draw, ALS 125-170

ALS

UNIT

SIZE

125A 380 60 132 132 3.4 10 14.4 943 604

140A 380 60 132 165 3.4 10 14.4 943 604

155A 380 60 165 165 3.4 12 14.4 943 604

170A 380 60 165 188 3.4 12 14.4 943 604

VOLTAGE HZ

208 240 240 5.8 10 23.7 1459 934
230 218 218 5.8 10 21.4 1628 1042

460 109 109 2.8 10 10.7 764 489
575 88 88 2.3 10 11.5 589 377
208 240 300 5.8 10 23.7 1459 934
230 218 272 5.8 10 21.4 1628 1042

460 109 136 2.8 10 10.7 764 489
575 88 109 2.3 10 11.5 589 377
208 300 300 5.8 12 23.7 1459 934
230 272 272 5.8 12 21.4 1628 1042

460 136 136 2.8 12 10.7 764 489
575 109 109 2.3 12 11.5 589 377
208 300 343 5.8 12 23.7 1459 934
230 272 310 5.8 12 21.4 1628 1042

460 136 155 2.8 12 10.7 764 489
575 109 124 2.3 12 11.5 589 377

RATED LOAD AMPS FAN LOCKED ROTOR AMPS

COMPRESSORS MOTORS

NO. 1 NO. 2

FLA MOTORS

(EACH)

NO. OF

FAN

MOTORS (EACH)

FAN PER COMPRESSORP

ACROSS-THE-LINE REDUCED INRUSH

IOMM ALS-1 47

Table 46, Amp Draw, ALS 175-204

ALS

UNIT

SIZE

175A 380 60 165 188 3.4 14 14.4 943 604

185A 380 60 188 188 3.4 14 14.4 943 604

195A 380 60 188 188 3.4 14 14.4 943 604

204A 380 60 188 188 4.1 14 20.0 943 604

VOLTAGE HZ

208 300 343 5.8 14 23.7 1459 934
230 272 310 5.8 14 21.4 1628 1042

460 136 155 2.8 14 10.7 764 489
575 109 124 2.3 14 11.5 589 377
208 343 343 5.8 14 23.7 1459 934
230 310 310 5.8 14 21.4 1628 1042

460 155 155 2.8 14 10.7 764 489
575 124 124 2.3 14 11.5 589 377
208 343 343 5.8 14 23.7 1459 934
230 310 310 5.8 14 21.4 1628 1042

460 155 155 2.8 14 10.7 764 489
575 124 124 2.3 14 11.5 589 377
208 343 343 7.8 14 30.5 1459 934
230 310 310 7.2 14 27.6 1628 1042

460 155 155 3.6 14 13.8 764 489
575 124 124 3.0 14 11.5 589 377

RATED LOAD AMPS LOCKED ROTOR AMPS

COMPRESSORS PER COMPRESSORP

NO. 1 NO. 2

FAN

MOTORS

FLA

(EACH)

NO. OF

FAN

MOTORS

FAN

MOTORS

(EACH)

ACROSS-THE-LINE REDUCED INRUSH

Table 47, Amp Draw, ALS 205-280

ALS

UNIT

SIZE

205A 380 60 132 132 165 3.4 16 14.4 943 604

220A 380 60 132 165 165 3.4 16 14.4 943 604

235A 380 60 165 165 165 3.4 18 14.4 943 604

250A 380 60 165 165 188 3.4 18 14.4 943 604

265A 380 60 165 188 188 3.4 18 14.4 943 604

280A 380 60 188 188 188 3.4 18 14.4 943 604

VOLTAGE HZ

208 240 240 300 5.8 16 23.7 1459 934
230 218 218 272 5.8 16 21.4 1628 1042

460 109 109 136 2.8 16 10.7 764 489
575 88 88 109 2.3 16 11.5 589 377
208 240 300 300 5.8 16 23.7 1459 934
230 218 272 272 5.8 16 21.4 1628 1042

460 109 136 136 2.8 16 10.7 764 489
575 88 109 109 2.3 16 11.5 589 377
208 300 300 300 5.8 18 23.7 1459 934
230 272 272 272 5.8 18 21.4 1628 1042

460 136 136 136 2.8 18 10.7 764 489
575 109 109 109 2.3 18 11.5 589 377
208 300 300 343 5.8 18 23.7 1459 934
230 272 272 310 5.8 18 21.4 1628 1042

460 136 136 155 2.8 18 10.7 764 489
575 109 109 124 2.3 18 11.5 589 377
208 300 343 343 5.8 18 23.7 1459 934
230 272 310 310 5.8 18 21.4 1628 1042

460 136 155 155 2.8 18 10.7 764 489
575 109 124 124 2.3 18 11.5 589 377
208 343 343 343 5.8 18 23.7 1459 934
230 310 310 310 5.8 18 21.4 1628 1042

460 155 155 155 2.8 18 10.7 764 489
575 124 124 124 2.3 18 11.5 589 377

RATED LOAD AMPS FAN LOCKED ROTOR AMPS

COMPRESSORS MOTORS FAN PER COMPRESSORP

NO. 1 NO. 2 NO. 3

FLA MOTORS

(EACH)

NO. OF

FAN

MOTORS

(EACH)

ACROSS-THE-LINE REDUCED INRUSH

48 IOMM ALS-1

Table 48, Motor Amps, ALS 300-425

ALS COMPRESSORS MOTORS NO. OF FAN PER COMPRESSORP

UNIT VOLTAGE HZ FLA FAN MOTORS

SIZE NO. 1 NO. 2 NO. 3 NO. 4 (EACH) MOTORS (EACH) ACROSS-THE-

208 240 240 300 300 7.8 20 30.5 1459 934
230 218 218 272 272 7.2 20 27.6 1628 1042

300A 380 60 132 132 165 165 4.1 20 20.0 943 604

460 109 109 136 136 3.6 20 13.8 764 489
575 88 88 109 109 3.0 20 11.5 589 377
208 240 300 300 300 7.8 20 30.5 1459 934
230 218 272 272 272 7.2 20 27.6 1628 1042

315A 380 60 132 165 165 165 4.1 20 20.0 943 604

460 109 136 136 136 3.6 20 13.8 764 489
575 88 109 109 109 3.0 20 11.5 589 377
208 300 300 300 300 7.8 20 30.5 1459 934
230 272 272 272 272 7.2 20 27.6 1628 1042

330A 380 60 165 165 165 165 4.1 20 20.0 943 604

460 136 136 136 136 3.6 20 13.8 764 489
575 109 109 109 109 3.0 20 11.5 589 377
208 300 300 300 343 7.8 20 30.5 1459 934
230 272 272 272 310 7.2 20 27.6 1628 1042

340A 380 60 165 165 165 188 4.1 20 20.0 943 604

460 136 136 136 155 3.6 20 13.8 764 489
575 109 109 109 124 3.0 20 11.5 589 377
208 300 300 343 343 7.8 24 30.5 1459 934
230 272 272 310 310 7.2 24 27.6 1628 1042

360A 380 60 165 165 188 188 4.1 24 20.0 943 604

460 136 136 155 155 3.6 24 13.8 764 489
575 109 109 124 124 3.0 24 11.5 589 377
208 300 343 343 343 7.8 24 30.5 1459 934
230 272 310 310 310 7.2 24 27.6 1628 1042

370A 380 60 165 188 188 188 4.1 24 20.0 943 604

460 136 155 155 155 3.6 24 13.8 764 489
575 109 124 124 124 3.0 24 11.5 589 377
208 343 343 343 343 7.8 24 30.5 1459 934
230 310 310 310 310 7.2 24 27.6 1628 1042

380A 380 60 188 188 188 188 4.1 24 20.0 943 604

460 155 155 155 155 3.6 24 13.8 764 489
575 124 124 124 124 3.0 24 11.5 589 377
208 343 343 343 343 10.0 24 48.1 1459 934
230 310 310 310 310 9.2 24 43.5 1628 1042

425A 380 60 188 188 188 188 5.5 24 26.4 943 604

460 155 155 155 155 4.6 24 21.8 764 489
575 124 124 124 124 3.8 24 17.4 589 377

RATED LOAD AMPS FAN LOCKED ROTOR AMPS

REDUCED INRUSH

LINE

IOMM ALS-1 49

Customer Wiring

Table 49, Customer Wiring with Single Point Connection (ALS 070-204)

WIRING TO UNIT POWER BLOCK WIRING TO DISCONNECT SWITCH

ALS

UNIT SIZE

070A 380 60 840 (2) #2 to 600 MCM 400 (1) 250 to 500 MCM

080A 380 60 840 (2) #2 to 600 MCM 250 (1) #4 to 350 MCM

090A 380 60 840 (2) #2 to 600 MCM 250 (1) #4 to 350 MCM

100A 380 60 840 (2) #2 to 600 MCM 250 (1) #4 to 350 MCM

125A 380 60 840 (2) #2 TO 600 MCM 400 (1) 250 to 500 MCM

140A 380 60 840 (2) #2 TO 600 MCM 400 (1) 250 to 500 MCM

155A 380 60 840 (2) #2 TO 600 MCM 600 (2) 250 to 500 MCM

170A 380 60 840 (2) #2 TO 600 MCM 600 (2) 250 to 500 MCM

175A 380 60 840 (2) #2 TO 600 MCM 600 (2) 250 to 500 MCM

185A 380 60 840 (2) #2 TO 600 MCM 600 (2) 250 to 500 MCM

195A 380 60 840 (2) #2 TO 600 MCM 600 (2) 250 to 500 MCM

204A 380 60 840 (2) #2 TO 600 MCM 600 (2) 250 to 500 MCM

VOLTS HZ

208 840 (2) #2 to 600 MCM 400 (1) 250 to 500 MCM
230 840 (2) #2 to 600 MCM 400 (1) 250 to 500 MCM

460 840 (2) #2 to 600 MCM 150 (1) #2 to 3/0
575 840 (2) #2 to 600 MCM 150 (1) #2 to 3/0
208 840 (2) #2 to 600 MCM 400 (1) 250 to 500 MCM
230 840 (2) #2 to 600 MCM 400 (1) 250 to 500 MCM

460 840 (2) #2 to 600 MCM 250 (1) #4 to 350 MCM
575 840 (2) #2 to 600 MCM 250 (1) #2 to 3/0
208 840 (2) #2 to 600 MCM 600 (1) 250 to 500 MCM
230 840 (2) #2 to 600 MCM 400 (1) 250 to 500 MCM

460 840 (2) #2 to 600 MCM 250 (1) #4 to 350 MCM
575 840 (2) #2 to 600 MCM 250 (1) #4 to 350 MCM
208 840 (2) #2 to 600 MCM 600 (1) 250 to 500 MCM
230 840 (2) #2 to 600 MCM 400 (1) 250 to 500 MCM

460 840 (2) #2 to 600 MCM 250 (1) #4 to 350 MCM
575 840 (2) #2 to 600 MCM 250 (1) #4 to 350 MCM
208 840 (2) #2 TO 600 MCM - See note 9
230 840 (2) #2 TO 600 MCM - See note 9

460 840 (2) #2 TO 600 MCM 400 (1) 250 to 500 MCM
575 840 (2) #2 TO 600 MCM 250 (1) #4 to 350 MCM
208 840 (2) #2 TO 600 MCM - See note 9
230 840 (2) #2 TO 600 MCM - See note 9

460 840 (2) #2 TO 600 MCM 400 (1) 250 to 500 MCM
575 840 (2) #2 TO 600 MCM 400 (1) 250 to 350 MCM
208 840 (2) #2 TO 600 MCM - See note 9
230 840 (2) #2 TO 600 MCM - See note 9

460 840 (2) #2 TO 600 MCM 400 (1) 250 to 500 MCM
575 840 (2) #2 TO 600 MCM 400 (1) 250 to 350 MCM
208 840 (2) #2 TO 600 MCM - See note 9
230 840 (2) #2 TO 600 MCM - See note 9

460 840 (2) #2 TO 600 MCM 400 (1) 250 to 500 MCM
575 840 (2) #2 TO 600 MCM 400 (1) 250 to 350 MCM
208 840 (2) #2 TO 600 MCM - See note 9
230 840 (2) #2 TO 600 MCM - See note 9

460 840 (2) #2 TO 600 MCM 400 (1) 250 to 500 MCM
575 840 (2) #2 TO 600 MCM 400 (1) 250 to 350 MCM
208 950 (2) #2 TO 600 MCM - See note 9
230 840 (2) #2 TO 600 MCM - See note 9

460 840 (2) #2 TO 600 MCM 600 (2) 250 to 500 MCM
575 840 (2) #2 TO 600 MCM 400 (1) 250 to 350 MCM
208 950 (2) #2 TO 600 MCM - See note 9
230 840 (2) #2 TO 600 MCM - See note 9

460 840 (2) #2 TO 600 MCM 600 (2) 250 to 500 MCM
575 840 (2) #2 TO 600 MCM 400 (1) 250 to 350 MCM
208 950 (2) #2 TO 600 MCM - See note 9
230 840 (2) #2 TO 600 MCM - See note 9

460 840 (2) #2 TO 600 MCM 600 (2) 250 to 500 MCM

TERMINAL SIZE CONNECTOR WIRE RANGE CONNECTOR WIRE RANGE

AMPS (COPPER WIRE ONLY)

POWER BLOCK OPTIONAL DISCONNECT SWITCH

SIZE

(COPPER WIRE ONLY)

50 IOMM ALS-1

575 840 (2) #2 TO 600 MCM 400 (1) 250 to 350 MCM

IOMM ALS-1 51

Table 50, Customer Wiring With Single Point Connection, ALS 205-425

WIRING TO UNIT POWER BLOCK WIRING TO DISCONNECT SWITCH

ALS

UNIT SIZE

205A 460 60 840 (2) #2 TO 600 MCM 600 (2) 250 to 500 MCM

220A 460 60 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM

235A 460 60 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM

250A 460 60 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM

265A 460 60 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM

280A 460 60 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM

300A 460 60 840 (2) #2 to 600 MCM 800 (2) 400 to 700 MCM

315A 460 60 840 (2) #2 to 600 MCM 800 (2) 400 to 700 MCM

330A 460 60 840 (2) #2 to 600 MCM 800 (2) 400 to 700 MCM

340A 460 60 840 (2) #2 to 600 MCM 800 (2) 400 to 700 MCM

360A 460 60 840 (2) #2 to 600 MCM 800 (2) 400 to 700 MCM

370A 460 60 840 (2) #2 to 600 MCM 800 (2) 400 to 700 MCM

380A 460 60 840 (2) #2 to 600 MCM 1200 (3) 500 to 750 MCM

425A 460 60 840 (2) #2 to 600 MCM 1200 (3) 500 to 750 MCM

VOLTS HZ

380 840 (2) #2 TO 600 MCM 600 (2) 250 to 500 MCM

575 840 (2) #2 TO 600 MCM 400 (1) 250 to 350 MCM
380 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM

575 840 (2) #2 to 600 MCM 400 (1) 250 to 500 MCM
380 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM

575 840 (2) #2 to 600 MCM 400 (1) 250 to 500 MCM
380 840 (2) #2 to 600 MCM 800 (2) 500 to 750 MCM

575 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM
380 840 (2) #2 to 600 MCM 800 (2) 500 to 750 MCM

575 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM
380 840 (2) #2 to 600 MCM 800 (2) 500 to 750 MCM

575 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM
380 840 (2) #2 to 600 MCM 800 (2) 400 to 700 MCM

575 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM
380 840 (2) #2 to 600 MCM 1200 (2) 500 to 750 MCM

575 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM
380 840 (2) #2 to 600 MCM 1200 (2) 500 to 750 MCM

575 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM
380 840 (2) #2 to 600 MCM 1200 (2) 500 to 750 MCM

575 840 (2) #2 to 600 MCM 600 (2) 250 to 500 MCM
380 950 (2) #2 to 600 MCM 1200 (3) 500 to 750 MCM

575 840 (2) #2 to 600 MCM 800 (2) 250 to 500 MCM
380 950 (2) #2 to 600 MCM 1200 (3) 500 to 750 MCM

575 840 (2) #2 to 600 MCM 800 (2) 400 to 700 MCM
380 950 (2) #2 to 600 MCM 1200 (3) 500 to 750 MCM

575 840 (2) #2 to 600 MCM 800 (2) 400 to 700 MCM
380 950 (2) #2 to 600 MCM 1200 (3) 500 to 750 MCM

575 840 (2) #2 to 600 MCM 800 (2) 400 to 700 MCM

TERMINAL SIZE CONNECTOR WIRE RANGE CONNECTOR WIRE RANGE

AMPS (COPPER WIRE ONLY)

POWER BLOCK OPTIONAL DISCONNECT SWITCH

SIZE

(COPPER WIRE ONLY)

52 IOMM ALS-1

Table 51, Customer Wiring With Multiple Point Power, ALS 125-204

WIRING TO UNIT POWER BLOCK

ALS

UNIT SIZE

125A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

140A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

155A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

170A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

175A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

185A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

195A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

204A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

VOLTS HZ

208 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

TERMINAL SIZE (AMPS) CONNECTOR WIRE RANGE (COPPER WIRE ONLY)

CKT 1 CKT 2 CKT 1 CKT 2

POWER BLOCK

IOMM ALS-1 53

Table 52, Customer Wiring With Multiple Point Power, ALS 205A-280A

WIRING TO UNIT POWER BLOCK

ALS

UNIT SIZES

205A 380 60 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM

220A 380 60 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM

235A 380 60 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM

250A 380 60 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM

265A 380 60 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM

280A 380 60 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM

VOLTS HZ

208 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM (2) #2 TO 600 MCM

TERMINAL SIZE (AMPS) CONNECTOR WIRE RANGE (COPPER WIRE ONLY)

CKT 1 CKT 2 CKT 3 CKT 1 CKT 2 CKT 3

POWER BLOCK

54 IOMM ALS-1

Table 53, Customer Wiring With Multiple Point Wiring, ALS 300A-425A

WIRING TO UNIT POWER BLOCK

ALS

UNIT SIZE

300A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

315A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

330A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

340A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

360A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

370A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

380A 380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

425A 460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

VOLTS HZ

208 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 950 950 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 950 950 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

460 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
208 950 950 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
230 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM
380 60 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

575 840 840 (2) #2 TO 600 MCM (2) #2 TO 600 MCM

TERMINAL SIZE (AMPS) CONNECTOR WIRE RANGE (COPPER WIRE ONLY)

CKT 1 CKT 2 CKT 1 CKT 2

POWER BLOCK

IOMM ALS-1 55

Electrical Data Notes

1. Allowable voltage limits:

Unit nameplate plus or minus 10 percent.

2. Unit wire size ampacity (MCA) is equal to 125% of the largest compressor-motor RLA plus 100%

of RLA of all other loads in the circuit including control transformer. Wire size ampacity for
separate 115V control circuit power is 15 amps for ALS125A through ALS280A.

3. Compressor RLA values are for wire sizing purposes only but do reflect normal operating current

draw at unit rated capacity. If unit is equipped with SpeedTrol condenser fan motors, the first
motor on each refrigerant circuit is a single phase, 1 hp motor, with a FLA of 2.8 amps at 460 volts
(5.6 amps at 208/230 volts). If the unit is not equipped with SpeedTrol, the standard fan motor will
be 1 1/2 hp, 3-phase (for ALS070A-280A) with a FLA as shown in the electrical tables. For
ALS300A-425A the standard fan motor will be 2 hp, 3-phase.

4. Compressor LRA for reduced inrush start is for the first winding. If the unit is equipped with

SpeedTrol motors, the first motor on each refrigerant circuit is a single phase, 1 hp motor, with a
LRA of 7.3 amps at 460 volts (14.5 amps at 208/230 volts). If the unit is not equipped with
SpeedTrol, the standard fan motor will be 1« hp, 3-phase with a LRA as shown in the electrical
tables.

5. Single point power supply requires a single disconnect to supply electrical power to the unit.

This power must be fused.

6. Multiple point power supply requires two independent power circuits on ALS125A-ALS195A,

ALS300-ALS425 and three independent power circuits on ALS205A-ALS280A each with separate
fused disconnects and a separate control circuit.

7. All field wiring to unit power block or optional non-fused disconnect switch must be copper.

8. Field wire size values given in tables apply to 75°C rated wire per NEC except for ALS185A-

ALS204A and ALS370A, ALS425A for 208V application or as noted.

9. Disconnect switches must be field supplied.

10. All wiring must be done in accordance with applicable local and national codes.

11. Recommended time delay fuse size or circuit breakers (Canadian units only) is equal to 150% of

the largest compressor-motor RLA plus 100% of remaining compressor RLAs and the sum of
condenser fan FLAs.

12. Maximum time delay fuse size or circuit breakers (Canadian units only) is equal to 225% of the

largest compressor-motor RLA plus 100% of remaining compressor RLAs and the sum of
condenser fan FLAs.

56 IOMM ALS-1

Table 54

Electrical Legend

IOMM ALS-1 57

Typical Field Wiring Diagram

Figure 28, Field Wiring, ALS 070A-425A

58 IOMM ALS-1

Unit Layout and Principles of Operation

Major Component Location

Figure 29, ALS 125-204

Figure 30, ALS 205-280

IOMM ALS-1 59

Figure 31, ALS 300-425

Control Center

All electrical controls are enclosed in a weather resistant control center with keylocked, hinged access
doors. The control center is composed of two separate compartments, high voltage and low voltage.
All of the high voltage components are located in the compartment on the right side of the unit.

The low voltage components are located on the left side with the 115 VAC terminals located behind
the deadfront panel. This protects service personnel from 115 VAC terminals when accessing the
adjustable and resettable controls.

Figure 32, Control Center Layout, ALS 125A-204

60 IOMM ALS-1

Figure 33, Control Center Layout, ALS 205A-280A

Figure 34, Control Center Layout, ALS 300A-425A

IOMM ALS-1 61

Sequence of Operation

The following sequence of operation is typical for McQuay models ALS chillers. The sequence may
vary depending on the software revision or various options which may be installed on the chiller.

Off conditions

With power supplied to the unit, 115 VAC power is applied through the control fuse F1 to the
compressor heaters (HTR1, HTR2, HTR3, HTR4 and evaporator heater) and the primary of the 24V
control circuit transformer. Note: Compressor heaters must be on for at least 12 hours prior to start-
up. The 24V transformer provides power to the MicroTech controller and related components. With
24V power applied, the controller will check the position of the front panel system switch. If the
switch is in the "stop" position the chiller will remain off and the display will indicate the operating
mode to be OFF: System Sw. The controller will then check the pumpdown switches. If any of the
switches is in the "stop" position, that circuit’s operating mode will be displayed as OFF:

PumpDwnSw. If the switches for both circuits are in the "Stop" position the unit status will display
OFF: PumpdownSw’s. If the remote start/stop switch is open the chiller will be OFF: RemoteSw. The

chiller may also be commanded off via communications from a separate communicating panel such as
the Remote Monitoring and Sequencing Panel or an Open Protocol interface. The display will show
OFF: RemoteComm if this operating mode is in effect. If an alarm condition exists which prevents
normal operation of both refrigerant circuits, the chiller will be disabled and the display will indicate
OFF: Alarm . If the control mode on the keypad is set to "Manual Unit Off," the chiller will be disabled
and the unit status will display OFF: ManualMode. Assuming none of the above stop conditions are
true, the controller will examine the internal time schedule to determine whether the chiller should be
permitted to start. The operating mode will be OFF: TimeClock if the time schedule indicates time
remaining in an "off" time period.

Alarm

The alarm light on the front panel will be illuminated when one or more of the cooling circuits has an
active alarm condition which results in the circuit being locked out. Unless the alarm condition affects
all circuits the remaining circuits will operate as required. Refer to IM 549 for details.

Start-up

If none of the above "off" conditions are true, the MicroTech controller will initiate a start sequence
and energize the chiller water pump output relay. The chiller will remain in the WaitForFlow mode until
the field installed flow switch indicates the presence of chilled water flow. If flow is not proven within
30 seconds, the alarm output will be turned on, the keypad display will be WaitForFlow and the chiller
will continue to wait for proof of chilled water flow. Once flow is established, the controller will sample
the chilled water temperature and compare it against the Leaving Chilled Water Set Point, the Control
Band, and the Start-up Delta Temperature, which have been programmed into the controller’s memory.
If the leaving chilled water temperature is above the Leaving Chilled Water Set Point plus ½ the Control
Band plus the adjustable Start-up Delta Temperature, the controller will select the refrigerant circuit
with the lowest number of starts as the lead circuit and energize the first stage of the Cool Staging
mode. The controller will start the compressor and energize the compressor liquid injection solenoid
along with the main liquid line solenoid. The controller will delay the opening of the electronic
expansion valve until the evaporator pressure decreases to a preset value. This is the evaporator
prepurge mode and the display will show Pre-Purge. The valve will then open allowing refrigerant to
flow through the expansion valve and into the evaporator and the display will show Opened EXV. If
additional cooling capacity is required, the controller will energize the additional cooling capacity by
activating the first compressor’s capacity control solenoids. As the system load increases, the
controller will start the lag refrigerant circuit in the same manner after interstage timers are satisfied.
The compressors and capacity control solenoids will automatically be controlled as required to meet
the cooling needs of the system. The electronic expansion valves are operated by the MicroTech
controller to maintain precise refrigerant control to the evaporator at all conditions.

62 IOMM ALS-1

Condenser Control

The first condenser fan stage will be started along with the first compressor to provide initial
condenser head pressure control. The MicroTech controller will activate the remaining condenser
fans as needed to maintain proper condenser pressure. The MicroTech controller continuously
monitors the condenser minus evaporator lift pressure and will adjust the number of operating
condenser fans as required. The number of condenser fans operating will vary with outdoor
temperature and system load. The condenser fans are matched to the operating compressors so that
when a compressor is off all fans for that circuit will also be off. On units with the fan speed control
option (SpeedTrol) the lead fan on each circuit will vary in speed to maintain condenser pressure at
lower outdoor temperatures.

Pumpdown

As the system chilled water requirements diminish. The compressors will be unloaded. As the system
load continues to drop, the electronic expansion valves will be stepped closed and the refrigerant
circuits will go through a pumpdown sequence. As the evaporator pressure falls below the
pumpdown pressure set point while pumping down, the compressor(s) and condenser fans will stop.
The unit has a one time pumpdown control logic; therefore, if the evaporator pressure rises while the
refrigerant circuit is in a pumpdown mode, the controller will not initiate another pumpdown sequence.
The controller will keep the unit off until a call for cooling occurs. Refer to the pumpdown control
section in IM549 for additional details. The chilled water pump output relay will remain energized until
the time schedule’s "on" time expires, the remote stop switch is opened, the system switch is moved
to the stop position, or a separate communications panel such as the Remote Monitoring and
Sequencing Panel or an Open Protocol interface deactivates the chilled water pump output.

Warning

The screw compressor must not be used as a pump out compressor for service work involving
removal of refrigerant from the compressor or evaporator. That is, the compressor must not be run
with the liquid line valve (king valve) closed. Portable recovery equipment must be used to remove
the refrigerant.

Figure 35, ALS Piping Schematic

IOMM ALS-1 63

Start-up and Shutdown

McQuayService personnel or authorized service agency

Most relays and terminals in the unit control center are powered when S1 is closed and the control
circuit disconnect is on. Therefore do not close S1 until ready for start-up.

Seasonal Start-up

Note: PS1, PS2, PS3, and PS4 will vary depending on the number of circuits.

1. Double check that the compressor suction and discharge shutoff valves are backseated. Always

replace valve seal caps.

2. Insure that the ball valves are open on the lines entering the evaporator.

3. Insure that the manual liquid line shutoff valve at the outlet of the subcooler is open.

4. Adjust the leaving chilled water temperature set point on the MicroTech controller to the desired

chilled water temperature. The control band is preset for 10 degrees Delta-T between the entering
and leaving evaporator water temperature at full load. If the Delta-T is outside an 8°-12°F range,
at full load, reset the control band as per the instructions found in the MicroTech IM Manual 549-

1.

5. Start the auxiliary equipment for the installation by turning on the time clock, and/or remote on/off

switch, and chilled water pump.

6. Check to see that pumpdown switches PS1, PS2, PS3 and PS4 are in the "Pumpdown and Stop"

(open) position. Throw the S1 switch to the "auto" position.

7. Under the "Control Mode" menu of the keypad place the unit into the automatic cool mode.

8. Start the system by moving pumpdown switch PS1 to the "auto" position.

9. After running circuit #1 for a short time, check for flashing in the refrigerant sightglass under

stable conditions.

10. Repeat steps 8 and 9 for PS2, PS3 and PS4 and the second, third and fourth refrigerant circuits.

11. Superheat is factory adjusted to maintain between 6° and 12°F.

WARNING

must perform initial start-up.

CAUTION

CAUTION

The superheat should be between 6°F and 12°F, with the liquid line sightglass full, once the system
temperatures have stabilized at the MicroTech set point temperatures.

Temporary Shutdown

Move pumpdown switches PS1, PS2, PS3 and PS4 to the "Pumpdown and Stop" position. After the
compressors have pumped down, turn off the chilled water pump. Caution: Do not turn the unit off
using the "S1" switch, without first moving PS1, PS2, PS3 and PS4 to the "Stop" position, unless it is
an emergency as this will prevent the unit from going through a pumpdown.

64 IOMM ALS-1

IMPORTANT

The unit has one time pumpdown operation. When PS1, PS2, PS3 and PS4 are in the "Pumpdown and
Stop" position the unit will pumpdown once and not run again until the PS1, PS2, PS3 and PS4
switches are moved to the auto position. If PS1, PS2, PS3 and PS4 are in the auto position and the
load has been satisfied the unit will go into one time pumpdown and will remain off until MicroTech
senses a call for cooling and starts the unit. Under no circumstance use the compressors for
pumpdown with the liquid line valves closed.

CAUTION

The unit must not be cycled off by using the evaporator pump or the disconnect switch.
It is important that the water flow to the unit is not interrupted before the compressors pumpdown to

avoid freeze-up in the evaporator.
If all power is turned off to the unit the compressor heaters will become inoperable. Once power is

resumed to the unit it is important that the compressor heaters are energized a minimum of 12 hours
before attempting to start the unit. Failure to do so could damage the compressors due to excessive
accumulation of liquid in the compressor.

Start-up After Temporary Shutdown

1. Insure that the compressor heaters have been energized for at least 12 hours prior to starting the

unit.

2. Start the chilled water pump.

3. With System switch S1 in the "on" position, move pumpdown switches PS1, PS2, PS3 and PS4 to

the "auto" position.

4. Observe the unit operation until the system has stabilized.

WARNING

If shutdown occurs or will continue through periods below freezing ambient temperatures, protect the
chiller vessel from freezing.

Extended Shutdown

1. Move the PS1, PS2, PS3 and PS4 switches to the manual pumpdown position.

2. After the compressors have pumped down, turn off the chilled water pump.

3. Turn off all power to the unit and to the chilled water pump.

4. Move the emergency stop switch S1 to the "off" position.

5. Close the compressor suction and discharge valves as well as the liquid line shutoff valves.

6. Tag all opened disconnect switches to warn against start-up before opening the compressor

suction and discharge valves and liquid line shutoff valves.

7. If glycol is not used in the system drain all water from the unit evaporator and chilled water piping

if the unit is to be shutdown during winter. Do not leave the vessels or piping open to the
atmosphere over the shutdown period.

8. Leave power applied to the evaporator heating cable if a separate disconnect is used.

IOMM ALS-1 65

Start-up After Extended Shutdown

1. With all electrical disconnects open, check all screw or lug type electrical connections to be sure

they are tight for good electrical contact.

2. Check the voltage of the unit power supply and see that it is within the ±10% tolerance that is
allowed. Voltage unbalance between phases must be within ±3%.

3. See that all auxiliary control equipment is operative and that an adequate cooling load is available
for start-up.

4. Check all compressor valve connections for tightness to avoid refrigerant loss. Always replace
valve seal caps.

5. Make sure system switch S1 is in the "Stop" position and pumpdown switches PS1, (PS2, PS3
and PS4) are set to "Pumpdown and Stop," throw the main power and control disconnect
switches to "on." This will energize crankcase heaters. Wait a minimum of 12 hours before
starting up unit. Turn compressor circuit breakers to "off" position until ready to start unit.

6. Vent the air from the evaporator water side as well as from the system piping. Open all water flow
valves and start the chilled water pump. Check all piping for leaks.

66 IOMM ALS-1

System Maintenance

General

On initial start-up and periodically during operation, it will be necessary to perform certain routine
service checks. Among these are checking the liquid line sightglasses and taking condensing and
section pressure readings. Through the MicroTech keypad, check to see that the unit has normal
superheat and subcooling readings. A recommended maintenance schedule is located at the end of
this section.

A Periodic Maintenance Log is located at the end of this manual. It is suggested that the report be
completed on a weekly basis. The log will serve as a useful tool for a service technician in the event
service is required.

Compressor Maintenance

Since the compressor is semi-hermetic requiring no oil separator, oil heaters nor pumps; no yearly
maintenance is normally required. However, vibration is an excellent check for proper mechanical
operation. Compressor vibration is an indicator of the requirement for maintenance and contributes to
a decrease in unit performance and efficiency. It is recommended that the compressor be checked with
a vibration analyzer at or shortly after start-up and again on an annual basis. When performing the
test the load should be maintained as closely as possible to the load of the original test. The initial
vibration analyzer test provides a benchmark of the compressor and when performed routinely can
give a warning of impending problems.

The compressor is supplied with a lifetime oil filter under normal operating conditions. However, it is a
good policy to replace this filter anytime the compressor is opened for servicing.

Lubrication

No routine lubrication is required on ALS units. The fan motor bearings are permanently lubricated.
No further lubrication is required. Excessive fan motor bearing noise is an indication of a potential
bearing failure.

Compressor oil must be Planetelf ACD68AW. McQuay Part Number 735030439 in a 5 gallon
container, 735030438 in 1 gallon size. This is synthetic polyolester oil with anti-wear additives and is
highly hygroscopic. Care must be taken to minimize exposure of the oil to air when charging oil into
the system.

Electrical Terminals

WARNING

Electric shock hazard. Turn off all power before continuing with following service.

Periodically check electrical terminals for tightness and tighten as required.

Condensers

The condensers are air-cooled and constructed of 3/8" (9.5mm) O.D. internally finned copper tubes
bonded in a staggered pattern into louvered aluminum fins. No maintenance is ordinarily required
except the routine removal of dirt and debris from the outside surface of the fins. McQuay
recommends the use of foaming coil cleaners available at most air conditioning supply outlets. Use
caution when applying such cleaners as they may contain potentially harmful chemicals. Care should
be taken not to damage the fins during cleaning.

IOMM ALS-1 67

If the service technician has reason to believe that the refrigerant circuit contains noncondensables,
purging may be required strictly following Clean Air Act regulations governing refrigerant discharge
to the atmosphere. The purge Schrader valve is located on the vertical coil header on both sides of
the unit at the control box end of the coil. Access panels are located at the end of the condenser coil
directly behind the control panel. Purge with the unit off, after shutdown of 15 minutes or longer, to
allow air to collect at the top of the coil. Restart and run the unit for a brief period. If necessary, shut
unit off and repeat the procedure. Follow accepted environmentally sound practices when removing
refrigerant from the unit.

Refrigerant Sightglass

The refrigerant sightglasses should be observed periodically. (A weekly observation should be
adequate.) A clear glass of liquid indicates that there is adequate refrigerant charge in the system to
insure proper feed through the expansion valve. Bubbling refrigerant in the sightglass, during stable
run conditions, indicates that the system may be short of refrigerant charge. Refrigerant gas flashing
in the sightglass could also indicate an excessive pressure drop in the liquid line, possibly due to a
clogged filter-drier or a restriction elsewhere in the liquid line (see Table 61 for maximum allowable
pressure drops). If subcooling is low add charge to clear the sightglass. If subcooling is normal (10°-
15°F) and flashing is visible in the sightglass check the pressure drop across the filter-drier.
Subcooling should be checked at full load with 70°F (21.1°C) outdoor air temperature and all fans
running.

An element inside the sightglass indicates the moisture condition corresponding to a given element
color. If the sightglass does not indicate a dry condition after about 12 hours of operation, the circuit
should be pumped down and the filter-drier changed.

Lead-Lag

A feature on all McQuay ALS air-cooled chillers is a system for alternating the sequence in which the
compressors start to balance the number of starts and run hours. Lead-Lag of the refrigerant circuits
is accomplished automatically through the MicroTech Controller. When in the auto mode the circuit
with the fewest number of starts will be started first. If all circuits are operating and a stage down in
the number of operating compressors is required, the circuit with the most operating hours will cycle
off first. The operator may override the MicroTech controller, and manually select the lead circuit as
circuit #1, #2, #3 or circuit #4.

68 IOMM ALS-1

Preventative Maintenance Schedule

PREVENTATIVE MAINTENANCE SCHEDULE

OPERATION WEEKLY MONTHLY

(Note 1)
General
Complete unit log and review (Note 3) X
Visually inspect unit for loose or damaged components X
Inspect thermal insulation for integrity X
Clean and paint as required X

Electrical
Check terminals for tightness, tighten as necessary X
Clean control panel interior X
Visually inspect components for signs of overheating X
Verify compressor heater operation X
Megger compressor motor every five years

Refrigeration
Leak test X
Check sight glasses for clear flow X
Check filter-drier pressure drop (see manual for spec) X
Perform compressor vibration test X

ANNUAL

(Note 2)

Condenser (air-cooled)
Clean condenser coils (Note 4) X
Check fan blades for tightness on shaft (Note 5) X
Check fans for loose rivets and cracks X
Check coil fins for damage X

Notes:

1. Monthly operations include all weekly operations.

2. Annual (or spring start-up) operations includes all weekly and monthly operations.

3. Log readings may be taken daily for a higher level of unit observation.

4. Coil cleaning may be required more frequently in areas with a high level of airborne particles.

5. Be sure fan motors are electrically locked out.

IOMM ALS-1 69

Service

CAUTION

1. Service on this equipment is to be performed by qualified refrigeration personnel familiar with

equipment operation, maintenance, correct servicing procedures, and the safety hazards inherent
in this work. Causes for repeated tripping of safety controls must be investigated and corrected.

2. Disconnect all power before doing any service inside the unit.

3. Anyone servicing this equipment shall comply with the requirements set forth by the EPA in

regards to refrigerant reclamation and venting.

Compressor Solenoids

The ALS unit screw compressors are equipped with 3 solenoids to control compressor unloading.
The solenoids are controlled by MicroTech outputs. See unit wiring diagrams. The solenoids are
energized at various compressor load conditions as indicated in the table below.

Table 55, Compressor Unloading

COMPRESSOR

LOADING %

100% Energized Off Energized

75% Energized Energized Off
50% Off Off Energized
25% Off Energized Off

COMPRESSOR UNLOADING SOLENOID STATUS

TOP BOTTOM FRONT BOTTOM REAR

SOLENOID SOLENOID SOLENOID

Location of the solenoids is as follows:

The top solenoid is on top of the compressor near the discharge end.
The bottom solenoids are on the lower side of the compressor on the opposite side from the terminal

box. The bottom front solenoid is the one closest to the discharge end of the compressor. The
bottom rear solenoid is the one closest to the motor end of the compressor.

If the compressor is not loading properly check the solenoids to see if they are energized per the
above chart. A complete check will include a check of the MicroTech output, the wiring to the
solenoid and the solenoid coil itself.

Filter-Driers

A replacement of the filter-drier is recommended any time excessive pressure drop is read across the
filter-drier and/or when bubbles occur in the sightglass with normal subcooling. A partially clogged
filter can also cause trips on the no liquid run sensor. The maximum recommended pressure drops
across the filter-drier are as follows:

Table 56, Filter-Drier Pressure Drop

PERCENT CIRCUIT MAXIMUM RECOMMENDED PRESSURE

LOADING (%) DROP ACROSS FILTER DRIER PSIG (KPA)

100% 10 (69)

75% 8 (55.2)
50% 5 (34.5)
25% 4 (27.6)

The filter-drier should also be changed if the moisture indicating liquid line sightglass indicates excess
moisture in the system.

70 IOMM ALS-1

During the first few months of operation the filter-drier replacement may be necessary if the pressure
drop across the filter-drier exceeds the values listed in the paragraph above. Any residual particles
from the condenser tubing, compressor and miscellaneous components are swept by the refrigerant
into the liquid line and are caught by the filter-drier.

The following is the procedure for changing the filter-drier core:

This procedure is slightly different from a typical reciprocating compressor unit due to the use of a
liquid injection feature on the ASL screw compressor unit. Anytime the compressor contactor is
closed, liquid from the liquid line is injected into the screw for cooling and sealing the rotor. This
liquid injection also occurs during normal pumpdown and limits how low a pumpdown pressure can be
achieved.

The standard unit pumpdown is set to stop pumpdown when 34 psig (235 kPa) suction pressure is
reached. To fully pump down a circuit beyond 34 psig (235kPa) for service purposes a "Full
Pumpdown" service mode can be activated using the keypad. Go to the "Alarm Spts" Menu on the
MicroTech keypad, step through the menu items until "FullPumpDwn" is displayed. Change the
setting from "No" to "Yes".

The next time either circuit is pumped down, the pumpdown will continue until the evaporator
pressure reaches 2 psig (14 kPa) or 60 seconds have elapsed, whichever occurs first. Upon
completing the pumpdown, the "FullPumpDwn" set point is automatically changed back to "No".

The procedure to perform a full service pumpdown for changing the filter-drier core is as follows:

1. Perform a normal pumpdown to 34 psig (235 kPa) by moving the pumpdown switch to the

"Pumpdown" position. This step will pump down the evaporator with compressor liquid injection
still active.

2. Under the "Alarm Spts", change the "FullPumpDwn" set point from "No" to "Yes".

3. The circuit status should be "Off:PumpDwnSw". Move the circuit pumpdown switch from

"Pumpdown and Stop" to "Auto". Also clear the anticycle timers through the MicroTech keypad.

4. The compressor should pump down the circuit until the evaporator pressure reaches 2 psig (14

kPa) or 60 seconds has elapsed, whichever occurs first.

5. Upon completing the full pumpdown per step 5, the "FullPumpDwn" set point is automatically

changed back to "No" which reverts back to standard 34 psig (235 kPa) stop pumpdown pressure.

6. If the pumpdown does not go to 2 psig (14 kPa) on the first attempt, one more attempt can be

made by repeating steps 3, 4 and 5 above. Do not repeat "FullPumpDwn" more than once to
avoid excessive screw temperature rise under this abnormal condition. A no liquid start alarm and
shutdown may occur during this procedure. Proceed as noted in step number 8.

7. The circuit is now in the deepest pumpdown which can safely be achieved by the use of the

compressor. Close the liquid line shutoff valve above the filter-drier, on the circuit to be serviced.
Any remaining refrigerant must be removed from the circuit by the use of a refrigerant recovery
unit.

Remove and replace the filter-drier(s). If the refrigerant circuit is opened for more than 10 minutes
evacuate the lines through the liquid line manual shutoff valve(s) to remove noncondensables that
may have entered during filter replacement. A leak check is recommended before returning the unit to
operation.

Liquid Line Solenoid Valve

The liquid line solenoid valves that shut off refrigerant flow in the event of a power failure does not
normally require any maintenance. (On a sudden power failure the electronic expansion valve

remains open at the position it was at when the power failure occurred. During normal operation
the EEV closes for automatic pumpdown and the liquid line solenoid valve closes only when the
compressor stops .) The solenoids may, however, require replacement of the solenoid coil or of the

entire valve assembly.

IOMM ALS-1 71

The solenoid coil can be checked to see that the stem is magnetized when energized by touching a
screwdriver to the top of the stem. If there is no magnetization either the coil is bad or there is no
power to the coil.

The solenoid coil may be removed from the valve body without opening the refrigerant piping after
first moving pumpdown switches PS1, PS2, and PS3 to the "manual pumpdown" position and opening
the S1 switch. For personal safety shut off and lock out the unit power.

The coil can then be removed from the valve body by simply removing a nut or snap-ring located at
the top of the coil. The coil can then be slipped off its mounting stud for replacement. Be sure to
replace the coil on its mounting stud before returning pumpdown switches PS1, PS2 and PS3 to the
"auto pumpdown" position. Failure to do so will lead to solenoid coil failure.

To replace the entire solenoid valve follow the steps involved when changing a filter-drier.

Liquid Injection Solenoid Valve

Liquid injection is required during compressor operation to seal and cool the rotor. A liquid injection
sensor is installed on the compressor to assure that liquid injection occurs whenever the compressor
is running. A failure of the liquid injection solenoid valve to open will cause the compressor to shut
down due to lack of liquid injection.

The liquid injection solenoid valve, like the liquid line solenoid valve, only closes when the
compressor stops. Since this valve is open during pumpdown the refrigerant in the line will cause the
suction pressure to rise 10 to 20 psig (69 to 138 kPa) after shutdown occurs. The solenoid coil and
valve body can be removed as in the same procedure as the liquid line solenoid valve but it is
important that the S1 switch be opened first.

Electronic Expansion Valve

The electronic expansion valve is located adjacent to the compressor. The refrigerant is piped to first
pass through the electronic expansion valve, then through the motor housing cooling the motor
before going into the evaporator. Refer to the Figure 35, ALS Piping Schematic.

The expansion valve meters the amount of refrigerant entering the evaporator to match the cooling
load. It does this by maintaining a constant superheat. (Superheat is the difference between the
actual refrigerant temperature of the vapor as it leaves the evaporator and the saturation temperature
corresponding to the evaporator pressure.) All ALS chillers are factory set between 8°F (4.5°C) and
12°F (6.6°C) superheat at 75% to 100% load and between 6°F (3.3°C) and 10°F (5.6°C) below 75% load.
The superheat is controlled by the microprocessor and is not adjustable.

The expansion valve, like the solenoid valve, should not normally require maintenance, but if it
requires replacement, the unit must be pumped down by following the steps involved when changing
a filter-drier.

If the problem can be traced to the electric motor only, it can be unscrewed from the valve body
without removing the valve but only after pumping the unit down. Disassemble valve at the brass hex
nut. Do not disassemble valve at the aluminum housing.

72 IOMM ALS-1

Figure 36,. Electronic expansion valve

Electronic Expansion Valve Operation

There are three colored indicator LEDs (green, red, yellow) located in the control panel on the
electronic expansion valve (EXV) board. When the control panel is first powered the microprocessor
will automatically step the valve to the fully closed (shut) position and the indicator lights on the EXV
will blink in sequence. The valve can also be heard closing as it goes through the steps. The valve
will take approximately 14 seconds to go from a full open position to a full closed position.

The position of the valve can be viewed at any time by using the MicroTech keypad through the
circuit pressure menus. There are a total of 760 steps between closed and full open.

A feature of the electronic expansion valve is a maximum operating pressure setting (MOP). This
setting limits the load on the compressor during start-up periods where high return evaporator water
temperatures may be present. The valve will limit the maximum suction pressure at start-up to
approximately 85 psig (586 kPa). The valve will close to a point necessary to maintain the 85 psig (586
kPa). During this time the superheat will rise above 12°F (6.6°C) and not drop below 12°F (6.6°C) until
the suction pressure drops below 85 psig (586 kPa). The valve will maintain evaporator pressure close
to 85 psig (586 kPa) until the evaporator water temperature decreases to approximately 55°F to 60°F
(12.7°C to 15.6°C).

When the circuit starts the valve opens as soon as the evaporator pressure decreases to 40 psig (275
kPa). At the end of the cooling cycle the valve closes causing the system to pump down. The valve
closes at the rate of approximately 55 steps per second, or from full open to full closed in
approximately 14 seconds. The valve closing during pumpdown will occur in approximately 20-30
seconds after the pumpdown switch is moved to the "Pumpdown and Stop" position.

IOMM ALS-1 73

Evaporator

The evaporator is the direct expansion, shell-and-tube type with refrigerant flowing through the tubes
and water flowing through the shell over the tubes. The tubes are internally finned to provide
extended surface as well as turbulent flow of refrigeration through the tubes. Normally no service
work is required on the evaporator.

Refrigerant Charging

ALS air-cooled screw chillers are shipped factory charged with a full operating charge of refrigerant
but there may be times that a unit must be recharged at the job site. Follow these recommendations
when field charging. Refer to the unit operating charge found in the Physical Data Tables, Table 21
through Table 27.

ALS air-cooled screw chillers are more sensitive to undercharging than to overcharging, therefore it is
preferable to be slightly overcharged rather than undercharged. The optimum charge is the charge
which allows the unit to run with a solid stream of liquid in the liquid line at all operating conditions.
When the liquid line temperature does not drop with the addition of 5 to 10 lbs of refrigerant, the
correct maximum charge has been reached. If the liquid line temperature does not drop and the
discharge pressure goes up 3-5 psig (20.7-34.5 kPa) as 5-10 lbs of refrigerant is added the correct
maximum charge has been reached.

Unit charging can be done at any steady load condition (preferably at 75 to 100% load) and at any
outdoor temperature (preferably higher than 70°F (21.1°C). Unit must be allowed to run 5 minutes or
longer so that the condenser fan staging is stabilized at normal operating discharge pressure. For best
results charge with two or more condenser fans operating on each refrigerant circuit.

The ALS units have a condenser coil design with approximately 15% of the coil tubes located in a
subcooler section of the coil to achieve liquid cooling to within 5°F (3°C) of the outdoor air
temperature when all condenser fans are operating. This is equal to about 15°F-20°F (8.3°C-11.1°C)
subcooling below the saturated condensing temperature when the pressure is read at the liquid valve
between the condenser coil and the liquid line filter drier. Once the subcooler is filled, extra charge will
not lower the liquid temperature and does not help system capacity or efficiency. However, a little
extra (10-15 lbs) will make the system less sensitive.

Note: As the unit changes load or fans cycle on and off, the subcooling will vary but should recover
within several minutes and should never be below 6°F (3.3°C) subcooling at any steady state
condition. Subcooling will vary somewhat with evaporator leaving water temperature and suction
superheat. As the evaporator superheat decreases the subcooling will drop slightly.

Excessive refrigerant losses can also leak oil from the system. When adding more than 25 lbs of
charge or if there is visible evidence of a significant oil leakage, add an additional oil equivalent to 0.04
pints for each pound of refrigerant required. (Example: For every 10 lbs. of refrigerant charge add .4
pints of oil.). The oil charge is 10% of the refrigerant charge by weight. The only acceptable oil is
Planetelf ACD68AW.

One of the following three scenarios will be experienced with an undercharged unit:

1. If the unit is slightly undercharged the unit will show bubbles in the sightglass. Recharge the

unit as described in the charging procedure below.

2. If the unit is moderately undercharged it will normally trip on freeze protection. Recharge the unit

as described in the charging procedure below.

74 IOMM ALS-1

3. If the unit is severely undercharged it will trip due to lack of liquid injection. In this case either

remove the remaining charge by means of a proper reclamation system and recharge the unit with
the proper amount of refrigerant as stamped on the unit nameplate, or add refrigerant through the
suction valve on the compressor. Feed liquid into the suction valve when the compressor is
running. If the unit is severely undercharged the unit may nuisance trip during this charging
procedure. If this happens close off the refrigerant from the tank and restart the unit. Once the
unit has enough charge so that it does not trip out, continue with step 2 of the charging
procedure below.

Procedure to charge a moderately undercharged ALS unit:

1. If a unit is low on refrigerant you must first determine the cause before attempting to recharge the

unit. Locate and repair any refrigerant leak. Evidence of oil is a good indicator of leakage,
however oil may not be visible at all leaks. Liquid leak detector fluids work well to show bubbles
at medium size leaks but electronic leak detectors may be needed to locate small leaks.

2. Add the charge to the system through the suction shutoff valve or through the Schrader fitting

on the tube entering the evaporator between the compressor and the evaporator head.

3. The charge can be added at any load condition between 25-100% load per circuit but at least two

fans should be operating per refrigerant circuit if possible. The suction superheat should be in
the 6°F-12°F (3.3°C-6.6°C) range.

4. Add sufficient charge to clear the liquid line sightglass and until all flashing stops in the

sightglass. Add an extra 15-20 lbs. of reserve to fill the subcooler if the compressor is operating at
50-100% load.

5. Check the unit subcooling value on the MicroTech display or by reading the liquid line pressure

and temperature at the liquid line near the filter-drier. The subcooling values should be between
6°F-20°F (6.6°C-11.1°C). The subcooling values will be highest at 75-100% load, approximately
12°F-20°F (6.6°C-11.1°C) and lowest at 50% load, approximately 6°F-12°F (3.3°C-6.6°C).

6. With outdoor temperatures above 60°F (15.6°C) all condenser fans should be operating and the
liquid line temperature should be within 5°F-10°F (2.8°C-5.6°C) of the outdoor air temperature. At
25-50% load the liquid line temperature should be within 5°F (2.8°C) of outdoor air temperature
with all fans on. At 75-100% load the liquid line temperature should be within 10°F (5.6°C) of
outdoor air temperature with all fans on.

7. Overcharging of refrigerant will raise the compressor discharge pressure due to filling of the
condenser tubes with excess refrigerant.

IOMM ALS-1 75

In-Warranty Return Material Procedure

In the U.S. and Canada

Compressor: In the event of a failure contact the nearest McQuayService office for assistance.
Components Other Than Compressors: Material may be returned only with permission from

authorized factory service personnel of McQuay International in Staunton, Virginia. A "return
goods" tag will be sent that is to be included with the returned material. Enter the required
information on the tag in order to expedite handling at our factories.

The return of the part does not constitute an order for replacement. Therefore, a purchase order must

be entered through your nearest McQuay representative. The order should include part name, part
number, model number and serial number of the unit involved.

Following McQuay's inspection of the returned part, and if it is determined that the failure is due to

faulty material or workmanship, and it is within the warranty period, credit will be issued against the
customer’s purchase order.

All parts shall be returned to the designated McQuay factory with transportation charges prepaid.

76 IOMM ALS-1

Standard Controls

Thermistor sensors

Note: Refer to IM 549 for a more complete description of the controls application, settings,
adjustments, and checkout procedures.

All sensors are premounted and connected to the MicroTech field wiring strip with shielded cable. A
description of each sensor is listed here.

Evaporator leaving water temperature - This sensor is located on the evaporator water outlet
connection and is used for capacity control of the chiller and low water temperature freeze protection.

Evaporator entering water temperature - This sensor is located on the evaporator water inlet
connection and is used for monitoring purposes and return water temperature control.

Evaporator pressure transducer circuit #1 - This sensor is located on the suction side of compressor
#1 and is used to determine saturated suction refrigerant pressure and temperature. It also provides
low pressure freeze protection for circuit #1.

Evaporator pressure transducer circuit #2 - This sensor is located on the section side of compressor
#2 and is used to determine saturated suction refrigerant pressure and temperature. It also provides
low pressure freeze protection for circuit #2.

Evaporator pressure transducer circuit #3 - This sensor is located on the suction side of compressor
#3 and is used to determine saturated suction refrigerant pressure and temperature. It also provides
low pressure freeze protection for circuit #3.

Evaporator pressure transducer circuit #4 - This sensor is located on the suction side of compressor
#4 and is used to determine saturated suction refrigerant pressure and temperature. It also provides
low pressure freeze protection for circuit #4.

Condenser pressure transducer circuit #1 - the sensor is located on the discharge of compressor #1
and is used to read saturated refrigerant pressure and temperature. The transducer will unload the
compressor should a rise in head pressure occur which is outside the MicroTech set point limits. The
signal is also used in the calculation of circuit #1 subcooling.

Condenser pressure transducer circuit #2 - The sensor is located on the discharge of compressor #2
and is used to read saturated refrigerant pressure and temperature. The transducer will unload the
compressor should a rise in head pressure occur which is outside the MicroTech set point limits. The
signal is also used in the calculation of circuit #2 subcooling.

Condenser pressure transducer circuit #3 - the sensor is located on the discharge of compressor #3
and is used to read saturated refrigerant pressure and temperature. The transducer will unload the
compressor should a rise in head pressure occur which is outside the MicroTech set point limits. The
signal is also used in the calculation of circuit #3 subcooling.

Condenser pressure transducer circuit #4 - The sensor is located on the discharge of compressor #4
and is used to read saturated refrigerant pressure and temperature. The transducer will unload the
compressor should a rise in head pressure occur which is outside the MicroTech set point limits. The
signal is also used in the calculation of circuit #4 subcooling.

Outside air - This sensor is located on the back of the control box on compressor #1 side. It measures
the outside air temperature, is used to determine if low ambient start logic is necessary and can be the
reference for low ambient temperature lockout.

Suction temperature circuit #1 - The sensor is located in a well brazed to circuit #1 suction line. The
purpose of the sensor is to measure refrigerant temperature to control and maintain proper superheat.

IOMM ALS-1 77

Figure 37, Sensor Locations, ALS 070-204

Table 57, Sensor Location, ALS 070 - 204

SENSOR DESCRIPTION SENSOR DESCRIPTION
NUMBER NUMBER

S00 Evap. Leaving water temp. S13 Suction temp. circ. #2
S01 Evap. Pressure transducer circ. #1 S14 Liquid line temp. circ. #1
S02 Evap. Pressure transducer circ. #2 S15 Liquid line temp. circ. #2
S03 Cond. Pressure transducer circ. #1 S16 Evap. Pressure transducer circ. #3
S04 Cond. Pressure transducer circ. #2 S17 Cond. Pressure transducer circ. #3
S06 Evap. Water temp reset S18 Suction temp circ. #3
S07 Demand limit S19 Liquid line temp. Circ. #3
S08 Evap. Entering water temp. S20 Discharge temp. circ. #1
S09 Outside air temp. S21 Discharge temp. circ. #2
S11 Total unit amps S22 Discharge temp. circ. #3
S12 Section temp. circ. #3

Figure 38, Sensor Locations, ALS 205-280

Table 58, Sensor Location, ALS 205 - 280

SENSOR DESCRIPTION SENSOR DESCRIPTION SENSOR DESCRIPTION
NUMBER NUMBER NUMBER

S00 Evap leaving water temp S09 Outside air temp S17 High pressure transducer circ. #3
S01 Low pressure transducer circ. #1 S10 Percent circuit amps circ. #1 S18 Suction temp circ. #3
S02 Low pressure transducer circ. #2 S11 Percent circuit amps circ. #2 S19 Liquid line temp circ. #3
S03 High pressure transducer circ. #1 S12 Suction temp circ. #1 S20 Discharge temp circ. #1
S04 High pressure transducer circ. #2 S13 Suction temp circ. #2 S21 Discharge temp circ. #2
S06 Evap water temp reset (field supplied) S14 Liquid line temp circ. #1 S22 Discharge temp circ. #3
S07 Demand limit (field supplied) S15 Liquid line temp circ. #2 S23 Percent circuit amps circ. #3
S08 Evap entering water temp S16 Low pressure transducer circ. #3

78 IOMM ALS-1

IOMM ALS-1 79

Figure 39, Sensor location, ALS 300-425

Table 59, Sensor Location, ALS 300 - 425

SENSOR DESCRIPTION SENSOR DESCRIPTION SENSOR DESCRIPTION
NUMBER NUMBER NUMBER

S00 Evap leaving water temp S09 Outside air temp S17 High pressure transducer circ. #3
S01 Low pressure transducer circ. #1 S10 Percent circuit amps circ. #1 & 3 S18 Suction temp circ. #3
S02 Low pressure transducer circ. #2 S11 Percent circuit amps circ. #2 & 4 S19 Liquid line temp circ. #3
S03 High pressure transducer circ. #1 S12 Suction temp circ. #1 S20

S04 High pressure transducer circ. #2 S13 Suction temp circ. #2 S21
S06 Evap water temp reset (field supplied) S14 Liquid line temp circ. #1 S22
S07 Demand limit (field supplied) S15 Liquid line temp circ. #2 S23
S08 Evap entering water temp S16 Low pressure transducer circ. #3

Low pressure transducer circ. #4
High pressure transducer circ. #4
Suction temp circ. #4
Liquid line temp circ. #4

Suction temperature circuit #2 - The sensor is located in a well brazed to circuit #2 suction line. The
purpose of the sensor is to measure refrigerant temperature to control and maintain proper superheat.

Suction temperature circuit #3 - The sensor is located in a well brazed to circuit #3 suction line. The
purpose of the sensor is to measure refrigerant temperature to control and maintain proper superheat.

Suction temperature circuit #4 - The sensor is located in a well brazed to circuit #4 suction line. The
purpose of the sensor is to measure refrigerant temperature to control and maintain proper superheat.

Liquid line temperature circuit #1 - The sensor is located in a well brazed to circuit #1 liquid line. It
measures the refrigerant temperature and is used to calculate subcooling.

Liquid line temperature circuit #2 - The sensor is located in a well brazed to circuit #2 liquid line. It
measures the refrigerant temperature and is used to calculate subcooling.

Liquid line temperature circuit #3 - The sensor is located in a well brazed to circuit #3 liquid line. It
measures the refrigerant temperature and is used to calculate subcooling.

Liquid line temperature circuit #4 - The sensor is located in a well brazed to circuit #4 liquid line. It
measures the refrigerant temperature and is used to calculate subcooling.

Demand limit - This requires a field connection of a 4-20 milliamp DC signal from a building
automation system. It will determine the maximum number of cooling stages which may be energized.

Evaporator water temperature reset - This requires a 4-20 milliamp DC signal from a building
automation system or temperature transmitter to reset the leaving chilled water set point.

Percent total unit amps - (optional) this is located in the power side of the control panel. An
adjustable voltage resistor and a signal converter board sends a DC signal proportional to the total
compressor motor current to the microprocessor.

80 IOMM ALS-1

Liquid presence sensor

Each compressor is equipped with a liquid sensor to assure that liquid flows to the compressor for
cooling and sealing during operation. The sensor will shutdown the compressor in the event no liquid
is sensed. At start-up the liquid sensor checks for excessive liquid in the compressor and will delay
start until the compressor heater transfers the liquid out of the compressor and into the condenser. A
trip by this sensor will cause an alarm message on the MicroTech display.

High condenser pressure control

MicroTech is also supplied with high pressure transducers on each refrigerant circuit. Although the
main purpose of the high pressure transducer is to maintain proper head pressure control, another
purpose is to convey a signal to the MicroTech control to unload the compressor in the event of an
excessive rise in discharge pressure to within 20 psi (138 kPa) of the condenser pressure control
setpoint of 380 psig (2620 kPa). Also, a MicroTech control setting will not allow additional circuit
loading at approximately 30 psi (207 kPa) below the high pressure switch trip setting. The high
pressure alarm is in response to the signal sent by the pressure transducer. The high pressure
transducer can be checked by elevating discharge pressure (see Mechanical High Pressure Safety
Control) and observing the MicroTech display (or a pressure gage), and unit operation as the
pressures pass the rising high pressure values noted. After the test reset the High Condenser
Pressure alarm set point to 380 psig (2620 kPa).

Mechanical high pressure safety control

The high pressure safety control is a single pole pressure activated switch that opens on a pressure
rise. When the switch opens, the control circuit is de-energized dropping power to the compressor
and fan motor contactors. The switch is factory made to open at 400 psig (2760 kPa) (+10 psig) and
reclose at 300 psig (2070 kPa). Although the high pressure switch will close again at 300 psig (2070
kPa), the control circuit will remain locked out and it must be reset through MicroTech.

The control is mounted on the compressor attached to a fitting ahead of the discharge shut off valve.
Remove wire 133 from terminal 20 of the MicroTech controller. This will disable all but one fan.

Observe the cut out point of the control through the MicroTech keypad display, or by means of a
service gauge on the back seat port on the discharge service valve. Important: Closely monitor the

High Pressure Control and stay within reach of the emergency stop switch. Do not let the pressure
exceed 420 psig (2900 kPa) during the test. If the condenser pressure reaches 420 psig (2900 kPa)
open the emergency stop switch. The MicroTech keypad display may read slightly lower than a
service gauge. Upon completion of the test reset the High Pressure Control back to 380 psig (2620
kPa).

To check the control on circuit #2 repeat the same procedure after removing wire 233 from terminal 30.

Compressor motor protection

The compressors are supplied with two types of motor protection. Solid state electronic overloads
mounted in the control box sense motor current to within 2% of the operating amps. The MUST TRIP
amps are equal to 140% of unit nameplate compressor RLA. The MUST HOLD amps are equal to
125% of unit nameplate RLA. A trip of these overloads can result from the unit operating outside of
normal conditions. Repeat overload trips under normal operation may indicate wiring or compressor
motor problems. The overloads are manual reset and must be reset at the overload as well as through
MicroTech.

The compressors also have a solid state Guardister  circuit which provides motor over temperature
protection. The Guardister  circuit has automatic reset but must also be reset through MicroTech.

FanTrol head pressure control

FanTrol is a method of head pressure control that automatically cycles the condenser fans in response
to condenser pressure. This maintains head pressure and allows the unit to run at all ambient air
temperatures within the control design parameters.

All ALS units have independent circuits with the fans being controlled independently by the
condensing pressure of each circuit. If one circuit is off all fans on that circuit will also be off. The

IOMM ALS-1 81

use of multiple fans enables the unit to have excellent head pressure control at low outside ambient
temperatures by cycling the fans to maintain the compressor discharge pressure within the desired
operating band.

At outdoor temperatures above approximately 65°F (18.3°C) all of the fans for a circuit will be
operating to achieve the most efficient unit operation. At any compressor load condition of 50% or
above the unit has the highest overall efficiency with all fans operating. When the compressor
unloads below 50% the last fan stage is cut off because the fan energy saved is more than the
increase of compressor power at this light loading. Below approximately 65°F (18.3°C) outdoor
temperature the fans are cycled off as needed on each refrigerant circuit by the MicroTech control to
maintain the compressor discharge pressure in the optimum range for best unit operation and highest
overall efficiency.

MicroTech controls fans in response to the system discharge pressure. The use of MicroTech to
stage on the fans as needed allows more precise control and prevents undesirable cycling of fans.

One fan always operates with the compressor and other fans are activated one at a time as needed.
The control uses 6 stages of fan control with four outputs to activate up to six additional fans per
circuit. MicroTech logic sequences fan contactors to stage one fan at a time. On units with six or
seven fans per circuit, a single fan is cut off when two fans are started to achieve adding one
operating fan. See Table 60.

Table 60, Fan Staging

MicroTech fan stage 0 1 2 3 4

Fan output relay on - 1 2 1,2 1,2,3

Total fans operating 1 2 3 4 6

MicroTech fan stage 0 1 2 3 4 5

Fan output relay on - 1 2 1,2 1,2,3 1,2,3,4

Total fans operating 1 2 3 4 6 8

MicroTech fan stage 0 1 2 3 4

Fan output relay on - 1 1,2 1,2,3 1,2,3,4

Total fans operating 1 2 3 4 5

MicroTech fan stage 0 1 2 3 4 5

Fan output relay on - 1 1,2 1,2,3 1,2,4 1,2,3,4

Total fans operating 1 2 3 4 5 6

MicroTech fan stage 0 1 2 3 4 5 6

Fan output relay on - 1 1,2 1,3 1,2,3 1,3,4 1,2,3,4

Total fans operating 1 2 3 4 5 6 7

MicroTech fan stage 0 1 2 3 4

Fan output relay on - 1 1,2 1,2,3 1,2,3,4

Total fans operating 1 2 3 4 5

MicroTech fan stage 0 1 2 3 4 5

Fan output relay on - 1 1,2 1,2,3 1,2,4 1,2,3,4

Total fans operating 1 2 3 4 5 6

MicroTech fan stage 0 1 2 3 4 5

Fan output relay on - 1 1,2 1,2,3 1,2,4 1,2,3,4

Total fans operating 1 2 3 4 5 6

ALS070A THRU ALS 080A (FANS PER CKT=3)

ALS090A THRU ALS 100A (FANS PER CKT=4)

ALS125A THRU ALS140A (FANS PER CKT=5)

ALS155A THRU ALS170A (FANS PER CKT=6) (Note 1)

ALS175A THRU 204A (FANS PER CKT=7) (Note 2)

ALS205A THRU ALS220A (FANS PER CKT=5)

ALS205A THRU ALS220A (FANS PER CKT=6) (Note 3)

ALS235A THRU 280A (FANS PER CKT=7)

(Continued)

82 IOMM ALS-1

(Table 60 Continued)

ALS300A THRU ALS340A (FANS PER CKT=5)

MicroTech fan stage 0 1 2 3 4

Fan output relay on - 1 1,2 1,2,3 1,2,3,4

Total fans operating 1 2 3 4 5

ALS360A THRU ALS425A (FANS PER CKT=6)

MicroTech fan stage 0 1 2 3 4 5

Fan output relay on - 1 1,2 1,2,3 1,2,4 1,2,3,4

Total fans operating 1 2 3 4 5 6

Notes:

1 On ALS155A thru 170A, two fans are controlled by fan output #4.
2 On ALS175A thru 204A, two fans each are controlled by fan outputs #3 and #4.
3 On ALS205A thru 220A Ckt #3 only and ALS235A thru 280A two fans are controlled by fan output #4.
Each output relay controls one fan except output relay #4 that controls two fans.

MicroTech evaluates several factors to determine the number of fans to be operated. These include:

1. The compressor loading as percent of full load.

2. The minimum lift pressure required at this load (The lift pressure equals the discharge pressure
minus the suction pressure.)

3. The addition of a control pressure band to the minimum lift pressure to prevent fan cycling.

4. A target discharge pressure is determined by adding the minimum lift pressure to the suction
pressure.

At any operating condition the MicroTech controller will determine the minimum lift pressure and a
target discharge pressure, and will add or remove operating fans in sequence until the discharge
pressure reaches the target value or falls within the control band of pressure set just above the target
pressure value.

Each fan added has a decreasing percentage effect so the control pressure band is smaller when more
fans are on and largest with only one or two fans on.

Unit operation, with FanTrol, is satisfactory down to outdoor temperatures of 30°F (-1.1°C). Below
this temperature the SpeedTrol option is required to regulate the speed of the first fan on the system
to adequately control the discharge pressure. SpeedTrol option allows unit operation to 0°F (-17.8°C)
outdoor temperature assuming that no greater than 5 mph wind. If SpeedTrol is used in conjunction
with wind baffles and hail guards, the unit can operate down to -10°F (-23°C).

For windy locations operating below 40°F (-1.1°C) outdoor air temperature, wind gusts must be
prevented from blowing into the unit coils by either locating the unit in a protected area or by the
addition of field supplied wind barriers or by mounting optional factory supplied wind barriers.

FanTrol operation example:

Unit operating at 100% load on both circuits
Suction Pressure = 65 psig (448 kPa)
Minimum lift pressure at 100% load = 12- psig (828 kPa)
Minimum discharge pressure = 65 + 120 psig = 185 psig (1276 kPa)
Discharge pressure control band = 35 psig (241 kPa)
Maximum discharge pressure = 185 + 35 = 220 psig (1517 kPa)

If the discharge pressure is between the minimum of 185 psig (1276 kPa) and maximum of 220 psig
(1517 kPa) the fan stages in operation are correct and if the pressure falls outside this range the
MicroTech controller will stage fans on or off to bring it within range.

IOMM ALS-1 83

CAUTION

SpeedTrol and FanTrol will provide reasonable operating refrigerant discharge pressures at the
ambient temperatures listed for them provided the coil is not affected by the existence of wind. Wind
baffles must be utilized for low ambient operation below 40°F if the unit is subjected to winds greater
than 5 mph.

Low ambient start

Low ambient start is incorporated into the MicroTech logic. The MicroTech will measure the
difference between freezestat and evaporator pressure and determine the length of time the
compressor will be allowed to run (to build up evaporator pressure) before taking the compressor off
line. The danger of allowing the compressor to run for to long before building up evaporator pressure
is that the evaporator could freeze. The low ambient timer setting is determined by the pressure as
shown in Table 61. If the low ambient timer is greater than the maximum time allowed the MicroTech
will shut off the compressor and display an alarm.

Table 61, Pressure Difference vs. Time to Alarm

PRESSURE DIFFERENCE BETWEEN TIME

FREEZESTAT AND EVAPORATOR (SECONDS)

12 psig (84 kPa) 180

8 psig (56 kPa) 240
4 psig (28 kPa) 300

0 psig (0 kPa) 360

Phase/voltage monitor

The phase/voltage monitor is a device that provides protection against three-phase electrical motor
loss due to power failure conditions, phase loss, and phase reversal. Whenever any of these
conditions occur, a contact opens to the MicroTech controller (PVR Input) which then de-energizes all
inputs.

When proper power is restored, contacts close and MicroTech enables compressors for operation.
When three-phase power has been applied, the output relay should close and the "run light" should

come on. If the output relay does not close, perform the following tests.

1. Check the voltages between L1-L2, L1-L3 and L2-L3. These voltages should be approximately

equal and within +10% of the rated three-phase line-to-line voltage.

2. If these voltages are extremely low or widely unbalanced check the power system to determine the

cause of the problem.

3. If the voltages are within range, use a phase tester to verify that phases are in A, B, C sequence

for L1, L2 and L3. Correct rotation is required for compressor operation. If incorrect phase
sequence is indicated, turn off the power and interchange any two of the supply power leads at
the disconnect switch.

This may be necessary as the phase/voltage monitor is sensitive to phase reversal. Turn on the
power. The output relay should now close after the appropriate delay.

Compressor short cycling protection

MicroTech contains logic to prevent rapid compressor restarting. Excessive compressor starts can be
hard on starting components and create excessive motor winding temperatures. The anti-cycle timers
are set for a five-minute stop-to-start cycle and a 15-minute start-to-start cycle. Both are adjustable
through MicroTech.

84 IOMM ALS-1

Optional Controls

SpeedTrol head pressure control (optional)

The SpeedTrol system of head pressure control operates in conjunction with MicroTech’s standard
head pressure control by modulating the motor speed on fans 11, 21, 31, and 41 in response to
condensing temperature. By reducing the speed of the last fan as the condensing pressure falls, the
unit can operate at lower ambient temperatures. Start-up with low ambient temperature is improved
because the SpeedTrol fans 11, 21,31, and 41 do not start until the condenser pressure builds up.

The SpeedTrol fan motor is a single phase, 208-230/460 volt, thermally protected motor specially
designed for variable speed application. The solid-state speed controls SC11, SC21, SC31, and SC41
are accessible through the panel directly above the control box. Units with 575 volt power have a
transformer mounted inside the condenser fan compartment to step the voltage down to 230 volts for
the SpeedTrol motor.

The SpeedTrol control starts to modulate the motor speed at less than 65°F (18.3°C) and maintains a
minimum condensing pressure of 170 to 180 psig (1172 to 1241 kPa) at full circuit load. For part load
operation the condensing pressure is allowed to fall below this level.

Reduced inrush (delta-delta) start (optional)

Reduced inrush start is available on all voltage units and consists of a 2-contactor arrangement with a
solid state time delay wired in series with the second contactor. Its purpose is to limit current inrush
to the compressors upon start-up. As each compressor starts, the power to the coil of the second
contactor is delayed for 1 second. With the first compressor contactor energized the windings are
connected in series to draw reduced amperage. With the second contactor energized the windings are
connected in parallel.

Control checkout is best accomplished by observation as each contactor is pulled in to see that the 1­second delay occurs before the second contactor pulls in.

Hot gas bypass (optional)

Hot gas bypass is a system for maintaining evaporator pressure at or above a minimum value that
allows continuos operation of the chiller at light load conditions. The purpose of doing this is to keep
the velocity of the refrigerant as it passes through the evaporator high enough for proper oil return to
the compressor when cooling load conditions are light.

The system consists of a pressure regulating valve with an integral solenoid as shown below. The
solenoid valve is factory wired to open whenever the unit thermostat calls for the first stage of
cooling. The pressure regulating valve is factory set to begin opening at 58 psig (400 kPa). For low
temperature operation the valve must be reset. This setting can be changed with an adjustment nut.
To raise the pressure setting, turn the adjustment screw clockwise. To lower the setting, turn the
screw counterclockwise. Do not force the adjustment beyond the range it is designed for, as this will
damage the adjustment assembly.

With the unit operating at 50% or lower circuit load the regulating valve opening can be determined.
The regulating valve opening point can be determined by slowly reducing the system load or
throttling the ball valve on the liquid line at the entrance to the evaporator. Observe the suction
pressure with refrigerant gauges when the hot gas bypass valve cuts in. A slower but alternate
method would be to lower the outlet water temperature to a value where the hot gas bypass valve
starts to open. When the bypass valve starts to open, the refrigerant line on the evaporator side of
the valve will begin to feel warm to the touch.

IOMM ALS-1 85

Figure 40, Hot Gas Bypass Piping

86 IOMM ALS-1

Controls, Settings and Functions

Table 62, Controls

DESCRIPTION FUNCTION SYMBOL SETTING RESET LOCATION

Compressor Heaters To provide heat to drive off liquid refrigerant when

compressor is off.
Compressor
Solenoid - Top
Compressor
Solenoid - Bottom
Compressor
Solenoid - Bottom
Evaporator Heater Coiled around the evaporator to prevent freezing the

Electronic Expansion
Valve Board
Electronic Expansion
Valve
Gardister Relay To provide motor temperature protection at about

Liquid Presence Sensor To protect compressor from starting with liquid or

Mechanical High
High Pressure Switch
MicroTech Unit
Controller
Motor Protector Relay To provide voltage isolation to the input board

Overloads (Compressor) to protect the compressor motor from over heating

Phase Voltage Monitor to prevent reverse rotation of the motor and protect

Reduced Inrush
Time Delay
Signal Converter To convert AC current signal volts to DC volts. SIG.Con

Solenoid Valve
Hot Gas Bypass
Solenoid Valve
Liquid Line
Solenoid Valve
Liquid Injection
SpeedTrol Head
Pressure Control
Surge Capacitor To protect from high voltage spikes and surges. C1,2,3,4 N/A N/A Control Box

Notes: Symbol column shows application components for four-compressor units. For two and three compressor units, not all components are applicable

In circuit 1,2,3 and 4 energizes to load 50% of

compressor capacity.

In circuit 1,2,3 and 4 energizes to unload 25% of

compressor capacity.

In circuit 1,2,3 and 4 energizes to load 25% of

compressor capacity.

water inside.

To provide power and step control to the EXV

stepper motors commanded by the MCB250.

To provide efficient unit refrigerant flow and control

superheat.

220oF (104oC).

running without liquid.

For UL, ETL, etc…safety code to prevent high

pressure above the relief valve.

To control unit and all safeties. Refer to IM 549. MCB250 N/A Refer

(ADI).

due to high amps.

it from under/over voltage.

To provide 1 sec delay for reduced inrush. TD5,6,7,8 Set 4Vdc

To allow the unit to run with very low load. SV5,6,9 N/A Discharge LIne

To provide a positive shut off of liquid refrigerant

when power is lost.

To only allow liquid injection when the compressor is

running.

To provide more uniform head pressure control. SC11,21,

HTR1,2,3,4 On, when compressor

is off.
CS11,21,
31,41
CS12,22,
32,42
CS13,23,
33,43
HTR5 38oF (3.3oC) N/A On the Cooler

EXV (Bd) N/A N/A Control Box

EXV In Controller Code N/A On the Compressor

GD1,2,3,4 None,

LPS1,2,3,4 400 psig (2760 kPa) Auto On the Compressor

MHPR1,2,3,4 Refer to IM 549 Auto Control Box

MPR1,2,3,4 Defined by

OL1-8 N/A Manual Control Box

PVM1,2,3,4 N/A Auto Control Box

V (SC)

SV1,2,7 N/A N/A Liquid Line

SV3,4,8 N/A N/A On Compressor

31,41

N/A N/A On the Compressor

N/A N/A On the Compressor

N/A N/A On the Compressor

Inherent in design

application

for full load amps

0-75 psig

(0-517 kPa)

N/A N/A Above Control Box

N/A On the Compressor

main liquid line

Auto Control Box

Control Box
to IM 549
Auto Control Box

N/A Control Box

N/A Control Box

Liquid Injection

Power Side

IOMM ALS-1 87

Troubleshooting Chart

Table 63, Troubleshooting

PROBLEM POSSIBLE CAUSES POSSIBLE CORRECTIVE STEPS

Compressor will not
run.

1. Main power switch open.

2. Unit S1 system switch open.

3. Circuit switch PS1, PS2, PS3, PS4 in pumpdown position.

4. Evap flow switch not closed.

5. Circuit breakers open.

6. Fuse blown or circuit breakers tripped.

7. Unit phase voltage monitor not satisfied.

8. Compressor overload tripped.

9. Defective compressor contactor or contactor coil.

10. System shut down by safety devices.

11. No cooling required.

12. Motor electrical trouble.

13. Loose wiring.

1. Close switch.

2. Check unit status on MicroTech display. Close switch.

3. Check circuit status on MicroTech display. Close switch.

4. Check unit status on MicroTech display. Close switch.

5. Close circuit breakers.

6. Check electrical circuits and motor windings for shorts or grounds.
Investigate for possible overloading. Check for loose or corroded
connections. Reset breakers or replace fuses after fault is
corrected.

7. Check unit power wiring to unit for correct phasing. Check voltage.

8. Overloads are manual reset. Reset overload at button on overload.
Clear alarm on MicroTech.

9. Check wiring. Repair or replace contactor.

10. Determine type and cause of shutdown and correct problem before
attempting to restart.

11. Check control settings. Wait until unit calls for cooling.

12. See 6,7,8 above.

13. Check circuits for voltage at required points. Tighten all power wiring
terminals

Compressor Noisy
or Vibrating

Compressor
Overload Relay
Tripped or Circuit
Breaker Trip or
Fuses Blown

Compressor Will
Not Load or Unload

Compressor Liquid
Injection Protection
Trip

1. Compr. Internal problem.

2. Liquid injection not adequate.

1. Low voltage during high load condition.

2. Loose power wiring.

3. Power line fault causing unbalanced voltage.

4. Defective or grounded wiring in the motor.

5. High discharge pressure.

1. Defective capacity control solenoids.

2. Unloader mechanism defective.

1. Liquid injection solenoid did not open at start.

2. Inadequate liquid to liquid injection at start due to a clogged
filter drier or low charge.

3. Inadequate liquid to liquid injection during run.

1. Contact McQuayService.

2. Check to assure liquid line sightglass is full during steady operation.

1. Check supply voltage for excessive voltage drop.

2. Check and tighten all connections.

3. Check supply voltage.

4. Check motor and replace if defective.

5. See corrective steps for high discharge pressure.

1. Check solenoids for proper operation. See capacity control section.

2. Replace.

1. Check and replace liquid injection solenoid.

2. Check liquid injection line sight glass. If flashing check filter drier and
unit charge.

3. Check liquid injection line sightglass. If flashing check filter-drier and
unit charge. Discharge pressure too low. Protect condenser coil from
wind.

High Discharge
Pressure

1. Discharge shutoff valve partially closed.

2. Noncondensables in the system.

3. Fans not running.

1. Open shutoff valve.

2. Purge the noncondensables from the condenser coil after shutdown.

3. Check fan fuses and electrical circuits.

88 IOMM ALS-1

High Discharge
Pressure

4. Fan control out of adjustment.

5. System overcharged with refrigerant.

6. Dirty condenser coil.

7. Air recirculation from outlet into unit coils.

8. Air restriction into unit.

4. Check that unit setup in MicroTech matches the unit model number.
Check MicroTech condenser pressure sensor for proper operation.

5. Check for excessive subcooling above 30oF (-1.1oC). Remove the
excess charge.

6. Clean the condenser coil.

7. Remove the cause of recirculation.

8. Remove obstructions near unit.

Low Discharge
Pressure

Low Suction
Pressure

High Suction
Pressure

1. Wind effect a low ambient temperature.

2. Condenser fan control not correct.

3. Low section pressure.

4. Compressor operating unloaded.

1. Inadequate refrigerant charge quantity.

2. Inadequate liquid to liquid injection at start. Clogged liquid
line filter-drier.

3. Expansion valve malfunctioning.

4. Insufficient water flow to evaporator.

5. Water temperature leaving evaporator is too low.

6. Evaporator tubes fouled.

7. Evaporator head ring gasket slippage.

8. Glycol in chilled water system

1. Excessive load - high water temperature.

2. Compressor unloaders not loading compressor.

3. Superheat is too low.

1. Protect unit against excessive wind into vertical coils.

2. Check that unit setup in MicroTech matches the unit model number.
Check SpeedTrol fan on units with SpeedTrol option.

3. See corrective steps for low suction pressure.

4. See corrective steps for failure to load.

1. Check liquid line sightglass. Check unit for leaks. Repair and
recharge to clear sightglass.

2. Check pressure drop across filter-drier. Replace cores.

3. Check expansion valve superheat and valve opening position.
Replace valve only if certain valve is not working.

4. Check water pressure drop across the evaporator and adjust gpm.

5. Adjust water temperature to higher value.

6. Inspect by removing water piping. Clean chemically.

7. Low suction pressure and low superheat both present may indicate an
internal problem. Consult factory.

8. Check glycol concentration

1. Reduce load or add additional equipment.

2. See corrective steps below for failure of compressor to load.

3. Check superheat on MicroTech display. Check suction line sensor
installation and sensor.

IOMM ALS-1 89

Periodic Maintenance Log

90 IOMM ALS-1

Post Office Box 2510, Staunton, Virginia USA [phone]