McQuay ALR 035D Installation Manual
Installation and
Maintenance Data
Bulletin No. IM 268-6
March 1995
Part No.
585558Y
SeasonPak@
Packaged Air Cooled Water Chiller
Models ALR 035D
Thru
185D
01995 McQuay International
Table of Contents
Introduction
General Description
.......................................................
Nomenclature................................................................
Inspection......................................................................
Installation
Handling.........................................................................
Location.........................................................................
Service Access..............................................................
Vibration Isolators..
....................................................
Water Piping..................................................................
.
Flow
Switch
Water Connections
Refrigerant Charge
Glycol
Solutions
Evaporator Water Flow and Pressure Drop
Physical Data
Major Components
Dimensional Data
...........................................................
.......
........................................................
........................................................
.........................................................
...............
..............................................................
......................................................
.....................................................
Field Wiring
ElectricalData Single Point
Electrical Data Multiple Point
VoltageLimitations
............................................
Compressor and Condenser Fan Motors
Customer Wiring
TypicalField Wiring
Information................................
Diagram.......................................
...................................
................................
.............
Unit Layout and Principles of Operation
Major Component
Locations.......................................
ControlCenter.......................................................
DisconnectLocation
Electrical
Legend
Sequence of Operation
....................................................
.........................................................
...............................................
Start-up and Shutdown
Pre Start-up.................................................................
Start-up........................................................................
Temporary Shutdown
Start-up After Temporary Shutdown..
Extended Shutdown
..................................................
.........................
....................................................
9-12
14-16
17-l 8
19-21
. ......
22-23
24-26
28-29
4, 5
7-8
8
13
21
27
28
29
30
31
32
32
32
32
33
3
System Maintenance
3
3
3
4
4
General.........................................................................
Fan
Motor Bearings
ElectricalTerminals..
Compressor Oil
Oil
Equalization
Condensers..
Refrigerant
Sightglass.................................................
.....................................................
....................................................
Level
............................................................
................................................................
Lead-Lag......................................................................
6
7
Service
7
7
Filter-Driers
LiquidLine Solenoid Valve
Thermostatic
Evaporator
..................................................................
Expansion Valve
...................................................................
In Warranty Return Material Procedure
Compressor
Components
.................................................................
Other Than
Appendix
Standard Controls
Thermostat
Control
Oil
Pressure Safety Control
High
Low
Compressor
..............................................................
Band
...........................................................
Pressure Control
Pressure Control
Lockout..............................................
Compressor Motor Protector
Pressure Control
FanTroll
Head
Optional Controls
Pressure Control
SpeedTroll
Head
High Ambient Control
High Return Water Control
Low Ambient Start
Freeze
Control
PartWinding
Phase/Voltage
Hot Gas Bypass
........................................................
Start...................................................
Monitor.....................................
......................................................
Controls,Settings and
Troubleshooting Chart
..................................................
..........................................
....................................
Compressors
......................
..............................37-38
............................................
.............................................
.................................
..............................
.........................
.............................................
.....................................
..................................................
41-42
Functions
.............................................
...........................43-44
45-46
33
33
33
33
33
34
34
34
34
34
35
35
36
36
37
37
38
38
38
38
39
40
40
41
41
41
41
42
Page 2 / IM 268
Product Warranty
...........................................................
See freeze protection references under the heading “Water Piping” on pages 6 and 13.
“FanTrol,” “McQuay.”
of McQuay International, Minneapolis, Minnesota, USA.
“Bulletin 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.”
SeasonPak” and “SpeedTrol” are registered trademarks
“
46
Introduction
General Description
McQuay type SeasonPak air cooled water chillers are complete, self-contained automatic refrigerating units that include the latest in engineered components arranged to
provide a compact and efficient unit. Each unit is completely
assembled and factory wired before evacuation, charging
and testing, and comes complete and ready for installation.
Each unit consists of twin air cooled condensers with integral
subcooler sections, multiple accessible hermetic compres-
sors, replaceable tube dual circuit shell-and-tube evaporator, and complete refrigerant piping. Liquid line components
that are included are manual liquid line shutoff valves, sightglass/moisture indicators, and double diaphragm hydraulic
element thermal expansion valves. Other features include
Nomenclature
Reciprocating Compressors
compressor crankcase heaters, an evaporator heater for
chilled water freeze protection, limited pumpdown during
“on” or “off” seasons, compressor lead-lag switch to alternate the compressor starting sequence, and sequenced
starting of compressors.
The electrical control center includes all safety and operating controls necessary for dependable automatic operation. Condenser fan motors are fused in all three conductor
legs and started by their own three-pole contactors. Compressors are not fused but may be protected by optional
circuit breakers, or
bythe
field installed fused disconnect for
protection.
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
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.
Note: Unit shipping and operating weights areavailable in
the Physical Data tables on pages 9 through 12.
Installation
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.
Handling
Care should be taken to avoid rough handling or shock due moving as this may result in serious damage.
to dropping the unit. Do not push or pull the unit from any- To lift the unit,
thing other than the base, and block the pushing vehicle
provided in the base of the unit. Spreader bars and cables
away from the unit to prevent damage to the sheet metal should be arranged to prevent damage to the condenser
cabinet and end frame (see Figure 1).
coils or unit cabinet (see Figure 2).
Never allow any part of the unit to fall during unloading or
Figure
1.
Suggested pushing arrangement
Blocklng Required
/-Across
Full Width
Figure 2. Suggested lifting arrangement
Spreader Bars
Recommended
(Use
CautIonI
2-1/2”
(64mm) diameter lifting holes are
Note: Number of fans can
vary from this diagram. but
lifting
method remains the
same.
(Note Control Box
LocatIon)
IM 268 / Page 3
Location
Care should be taken in the location of the unit to provide
proper airflow to the condenser, minimizing effects on condensing pressure.
Due to the vertical condenser design of the ALR 110
through 185 chillers, it is recommended that the unit is
oriented to that prevailing winds blow parallel to the unit
lenght, thus minimizing the effects on condensing pressure.
If it is not practical to orient the unit in this manner, a wind
deflector should be constructed.
Minimizing clearances as shown in Figure 3 will prevent
most discharge air recirculation to the condenserwhich will
have a significant effect on unit performance.
Table 7. Clearances
Au? WJIT SIZE
035D -
070D
085D - 185D 10 ft. (3048mm) Min.
Notes:
1.
Minimum clearance between units is 1’2 ft.
2.
Units must not be installed in a pit that
3.
Minimum clearance on each side is 12 ft. (3658mm) when installed w a pit.
“X”
DHWENION
8
ft. (2438mm) Min.
(3658mm).
IS
deeper than the height of the
unit.
Service Access
Figure 3. Clearance requirements
;I-~-:_1
Each end of the unit must beaccessible after installation for assembly should be removed for service.
periodic service work. Compressors, filter-driers, and manual
liquid line shutoff valves are accessible on each side of the
to the
unit adjacent
control box. High pressure, low pressure,
The fan blade and fan motor rain shield must be removed
for access to wirinq terminals at the top of the motor.
and motor protector controls are on the compressor.
Freezestats and cooler barrel thermostats are nearthecooler.
Most other operational, safety and starting controls are
located in the unit control box.
On all ALR units the condenser fans and motors can be
removed from the top of the unit. A complete fan/motor
Disconnect all power to the unit while servicing con-
denser fan motors. Failure to do so may cause bodily
injury or death.
Vibration Isolators
Vibration isolators are recommended for all roof mounted
installations or wherever vibration transmission is a consideration. Table 2 lists spring isolators for all ALR unit sizes.
Figure4 shows isolator locations in relation to the unit control
center. Figure 5 gives dimensions that are required to secure
Table 2. Vibration isolators (spring) Table 3. Spring flex isolators
ICPl-31 (CPl-31 (CPl-31 /CPl-31 (CPi-31 (CPl-31
10
ID
1
CPl-321CPl-32
1
CPl-321CPl-321CPl -321CPI
-32
each McQuay isolator selection to the mounting surface.
Table 4 shows the isolator loads at each location in Figure 4,
and the maximum loads for each McQuay selection are
shown in Table 3.
L
Page 4
I IM
1300
135D
14!H3
?soD
1650
17Cm
1950
268
CPZ-28 CP2-28
CP2-31 CP2-31
CP2-31
CP2-32 CP2-32
CP2-31
CP2-32 CP2-32 CP2-32
CP2-31
CP2-32 CP4-27 CP2-32
CP2-32 CP2-32 CP4-27 CP2-32
CP4-27 CP2-32 CP2-32 CP4-27 CP2-32 CP2-32
CP4-27 CP2-32 CP2-32 CP4-27 CP2-32 CP2-32
CP4-27 CP2-32 CP2-32 CP4-27 CP2-32 CP2-32
CP2-31
CP2-32
CP2-28 CP2-28
CP2-31 CPZ-31 CP2-32
CP2-31
CP2-32 CP2-32
CP2-31
CP2-31
CPZ-32
CP2-31
J
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 re-
quired 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 eliminatorstoreducevibrationand noisetrans-
mission 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 should be placed at the lowest points
in the system.
Some means of maintaining adequate system water
4.
pressure (e.g., expansion tank or regulating valve).
Temperature and pressure indicators located at the unit
5.
to aid in unit servicing.
A strainer or some means of removing foreign matter
6.
from the water before it enters the pump. It 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
thus keep system performance up.
A strainer should also be placed in the water lines just
7.
prior to
the inlets of the evaporator and condenser. This
will aid in preventing foreign material from entering and
decreasing the performance of the evaporator.
8.
The shell-and-tube cooler has a thermostat and heating
cable to prevent feeze-up, due to low ambient, down to
-20°F (-29°C). It is suggested that the heating cable be
wired to a separate 11 OV 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 feezing.
9.
If the unit is used as a replacement chiller on a previously
existing piping system, the system should bethoroughly
flushed prior to unit installation and then regular water
analysis and chemical water treatment on the evaporator and condenser is recommended immediately at
equipment start-up.
10. The total quantity of water in the system should be
11. In the event glycol is added to the water system, as an
If a separate disconect is
the cooler heating cable, it should be clearly marked
so that it is not accidentally shut off during cold
seasons.
preliminary leak check should be made.
moisture condensationand 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.
Figure 6. ALR evaporator
J
sufficient to prevent frequent “on-off” cycling. The total
quantity of water, in the system, turnover rate should not
be less than 15 minutes.
afterthought for freeze protection, recognize that the
refrigerant suction pressure will be lower, cooling performance less, and water side pressure drop is greater.
If the percentage of glycol is large, or if propylene is
employed instead of ethylene glycol, the added pressure drop and loss of performance could be substantial.
Reset the freezestat and low leaving water alarm temperatures. The freezestat is factory set to default at 36°F
(2.2%). Reset the freezestat setting to approximately
to 5°F (2.3” to 2.8%) below the leaving chilled water
setpoint temperature. See the section titled
“Glycol
Solutions” for additional information concerning glycol.
used for the
110V supply to
Prior to insulating the piping and filling the system, a
Piping insulation should include a vapor barrierto prevent
1
1L
T-
4”
III
Figure 7. Typical field evaporator water piping
Page 6 / IM 268
Pressure
Gauge
Vibration
Eliminator
Lf
Water
Strainer
Gate
Valve
awitch
Note: Chilled water piping should be insulated.
Balancing
Valve
Gate
Valve
Flow
A water flow switch must be mounted in either the entering
or leaving water line to insure that there will be adequate
water flow and cooling load to the evaporator before the unit
can start. This will safeguard against slugging the compres-
sors on startup. 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 00175033-00. It is a “paddle” type switch and
Switch
adaptable to any pipe size from 1” (25mm) to 6” (152mm)
nominal. Certain minimum flow rates are required to close
the switch and are listed in Table 6. Installation should be as
shown in Figure 8. Electrical connections in the unit control
center should be made at terminals 5 and 6. The normally
open contacts of the flow switch should be wired between
these two terminals. There is also a set of normally closed
contacts on the switch that could be used for an indicator
light or an alarm to indicate when a “no flow” condition exists.
Table 6. Flow switch minimum flow rates
2% ( 63.5)
3( 76.2) 30.00
4
(101.6)
5
(127.0)
6
(152.4)
Note: Water pressure differential switches are not recommended for outdoor
applications.
24.30 (1.50)
(1.90)
39.70
(2.50)
58.70
(3.70)
79.20
k5.00)
Water Connections
Water piping to thecooler can be brought up from the bottom
of the unit or through the side between the vertical supports.
The dimensional data on pages 14 through 16 give the
necessary dimensions and locations for all piping connections.
Refrigerant Charge
All units are designed for use with Refrigerant 22 and are
shipped with an operating charge. The operating charge for
Figure 8.
L5’
(127mm)
Min.
After Switch
Note: On units sizes
Dia.
150D
through
L
5’ (127mm) Pipe Dia.
Min. Before Switch
185D
there is a
diagonal bracket 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.
each unit is shown in the Physical Data tables on pages 9
through 12.
Glycol Solutions
The system glycol capacity, glycol solution flow rate in gpm,
and pressure drop through the cooler may be calculated
using the following formulas and table.
Note: The procedure below does not specify the type of
glycol. Use thederatefactors found in Table 7 for corrections
when using ethylene glycol and those in Table 8 for propylene 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 C
to find the chiller’s capacity in the glycol system.
2.
Flow -To determine evaporator gpm (or AT) knowing AT
(or gpm) and capacity:
Glycol
gpm =
24
x
capacity
For Metric Applications
(or AT) knowing AT (or Ips) and
Glycol Ips =
kW
4.18 x
(glycol)
AT
x G (from table)
-To determine evaporator Ips
kW:
x Flow (from table)
AT
Pressure drop
-To determine pressure drop through
the cooler, when using glycol, enter the water pressure
drop curve on page8 at the actual glycol gpm. Multiply the
water pressure drop found there by P to obtain corrected
glycol pressure drop.
To determine glycol system
kW
by factor K.
multiply the
water system
kW,
Test coolant with a clean, accurate glycol solution hy-
drometer (similar to that found in service stations) to deter-
mine the freezing point. Obtain percent glycol from the
freezing point table below. On glycol applications it is nor-
mally recommended by the supplier that a minimum of 25%
solution by weight be used for protection against corrosion.
Do not use an automative grade antifreeze. Industrial
grade glycols must be used. Automotive antifreeze
contains inhibitors which will cause plating on the
copper tubes within the chiller evaporator. The type
and handling of glycol used must be consistent with
local codes.
IM 268 / Page 7
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