McQuay ALR-060A Installation Manual

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Page 1

BULLETIN NO. IM 172

JULY 1978

INSTALLATION AND

MAINTENANCE DATA

PACKAGED AIR COOLED WATER CHILLER

TYPE ALR-060 THRU 130A

GROUP

McQuay-PERFEX

Inc. 13600 Industrial Park Blvd., P.O. Box 1551, Minneapolis, Mn. 55440

Page 2

INTRODUCTION

NOMENCLATURE

PRE-INSTALLATION

INSTALLATION

HANDLING LOCATION

ACCESS FOR SERVICING

VIBRATION ISOLATORS

WATER PIPING

PIPING PRACTICES CHILLED WATER THERMOSTAT FLOW SWITCH

PIPING CONNECTIONS FIELD WIRING START-UP AND SHUT-DOWN ELECTRICAL

CONTROL CENTER

CONTROL PANEL LAYOUTS

ELECTRICAL LEGEND

SEQUENCE OF OPERATION

PUMPDOWN

MAJOR COMPONENT LOCATIONS

WIRING SCHEMATICS

DESCRIPTION OF UNIT CONTROLS UNIT MAINTENANCE

GENERAL

REFRIGERANT SIGHT GLASS

FILTER-DRIERS

LIQUID LINE SOLENOID VALVE THERMOSTATIC EXPANSION VALVE EVAPORATOR CONDENSERS COMPRESSOR WEAR AND LEAD-LAG COMPRESSOR OIL LEVEL FAN BELT TENSION FAN SHAFT BEARINGS FAN MOTOR BEARINGS ELECTRICAL TERMINALS

IN WARRANTY RETURN MATERIAL PROCEDURE

TROUBLE SHOOTING CHART

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CYCLE

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.-.8-l

..11-13 ..13-16 ..16-4 7

.-.16-l

..18-19

..21-3 9

..40-4 7 ..47-5 1

..48-4 9 ..49-5 0

.......................

. . .

..4- 7

. .

..5- 6 ..6- 7

..8- 9

..10

7 ..17 ..18

..19

..2 0

..4 7 ..4 7 ..4 7 ..4 8

..5 0 ..5 0 ..5 0

..5 1

..5 1 ..5 1 ..5 1 ..5 1 ..5 2

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INTRODUCTION

McQuay type ALR 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.

evacuation,

installation. with integral subcooler sections, pressors,

and complete refrigerant piping.

included are:

filter driers, dicators, valves.

evaporator heater for chilled water freeze protection, recycling

pumpdown during "on" or "off" seasons,

alternate the compressor starting sequence, of compressors.

The electrical control center includes all safety and operating con-

trols necessary for dependable automatic operation.

and fan motor is fused in all three conductor legs and started by its own three pole contactor.

Each unit is completely assembled and factory wired before

charging and testing,

Each unit consists of: twin air cooled condensers

replaceable tube dual circuit shell and tube evaporator,

manual liquid line

liquid line solenoid valves, sight glass/moisture in-

and double diaphragm hydraulic element thermal expansion

Other features include:

and comes complete and ready for

multiple accessible hermetic com-

Liquid line components that are

shutoff

compressor crankcase heaters, an

compressor lead lag switch to

valves,

and sequenced starting

replaceable core

Each compressor

NOMENCLATURE

RECIPROCATING COMPRESSORS LOW POWER CONSUMING AIR COOLED CONDENSER

-It

ALR- 085AD

DUAL REFRIGERANT CIRCUITS DESIGN VINTAGE

NOMINAL CAPACITY (TONS)

PRE-INSTALLATION

Inspection

When the equipment is received,

against the bill of lading to insure a complete shipment. should be carefully inspected for damage upon arrival.

damage should be reported to the carrier and a claim should be filed.

The unit serial plate should be checked before unloading the unit to

be sure that it agrees with the power supply available.

all items should be carefully checked

All units

All shipping

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Page 4

Handling

INSTALLATION

Care should betaken to avoid rough handling or shock due to ping the unit.

Do not push or pull the unit from anything other

drop-

than the base,and block the pushing vehicle away from the unit to prevent damageto the sheet metal cabinet.

FIGURE 1

SUGGESTED PUSHING ARRANGEMENT

GOOD PUSHING ARRANGEMENT

CABINET DAMAGE UNLIKELY

(See Figure 1).

BLOCKING

POOR PUSHING ARRANGEMENT

CABINET DAMAGE LIKELY

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

To lift the unit,

2%"

diameter lifting holes are

provided in the base of the unit. Spreader bars and cables should bearranged to prevent damage to the condenser coils or unit cabinet.

FIGURE 2

SPRE

SUGGESTED LIFTING ARRANGEMENT

:ADER

(See Figure 2).

Page 4

‘LMUST

(NOTE CONTROL

USE THESE RIGGING HOLES

Box

LOCATION)

Page 5

Location

Due to the vertical condenser design, it is recommended that certain precautions be taken before installation to orient the unit so that prevailing winds blow parallel to the unit length thus minimizinq effects on condensing pressure. the unit in this manner, a wind

If it is not practical to orient

deflecting fence should be

consi-

dered.

It is also necessary to provide the unit for service access and 60 in.

fan diameter) should be allowed on each side of the unit

for condenser air inlet and compressor removal on units 060

adequate clearance on all sides of

satisfactory performance.

At least

065.

If parallel units are installed side by side, 120 in. should be allowed between units.

This will prevent excessive condensing temperatures and enhance system performance and operating economy. Clearance for service access should be at least 78 in. at the control center end for compressor removal on units 075 thru 130 and sufficient at the end opposite the control center for evaporator tube replacement.

FIGURE 3

60” MINIMUM-CLEARANCE

These clearances are illustrated in Figure 3.

CLEARANCE AROUND UNIT

FOR AIR INLET

60” MINIMUM CLEARANCE

FOR AIR INLET AND COMPRESSOR

REMOVAL ON ALR-060,065

NOTE: Minimum vertical clearance above unit should be

10 feet

I I

Access for Servicing

Each end of the unit must be accessible after installation for peri-

odic service work.

Compressors,

filter driers,

and manual liquid

line shutoff valves are accessible from the control center end of the

unit through removable access panels on unit sizes 075 thru 130 and

hinged side access doors on unit sizes 060 and 065. safety, They are protected by a keylocked,

tains internal "dead front" nel from high operational controls.

located just below the main control center.

and starting controls are located in the unit control center.

weatherproof enclosure which con-

doors for protection of service person-

voltage starting controls while servicing low voltage

All resettable or adjustable controls are

There is one resettable

All operational,

control enclosure on each side of the unit and each encl.osure contains

controls for compressors on that side of the unit.

Capped connections

for field service gauges are also located inside these enclosures. In addition,

each of these enclosures are removable to improve access to

compressors for field replacement.

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The condenser fans, motors,

and drives are accessible through a walk-

in, keylocked access door on units ALR-075 thru 130 or a removable access panel on units ALR-060 and located at the end of the unit opposite the control center.

065.

The access door or panel is

Expan-

sion valves are accessible from the same access door on unit sizes 075 thru 130 and from side access doors at the control center end

on unit sizes 060 and 065.

An internal fan guard is located below the condenser fans and drives on units 075 thru 130.

This guard must be removed to service the

fan drives but must always be re-installed when service work is com-

plete.

On unit sizes 060 and 065,

an interlock switch kills power

to condenser fans whenever the access panel is removed for service

work on fans or drives.

CAUTION:

Disconnect all power to the unit while

servicing condenser fan drives.

Vibration Isolators Vibration isolators are recommended for all roof mounted installa-

tions or wherever vibration transmission is a consideration.

lists spring isolators for all ALR unit sizes.

tor locations in relation to the unit control center.

Figure 4 shows isola-

Figure 5 gives

Table 1

dimensions that are required to secure each McQuay isolator selection to the mounting surface.

For applications which require a higher degree of isolation efficiency, Table 2 shows the isolator loads at each location shown in Figure 4, and the maximum loads for each McQuay selection.

TABLE 1

ALR LOCATIONS LOCATIONS UNIT SIZE

060A 065A 075A 2 164048-28 085A 2 16404B-28 105A

IIOA

120A 130A

l&4

ORDERING

NUMBER NUMBER

(877-j

216404B-27 216404B-27 216404B-27

2164048.31

216404B.31 216404B.32 216404B-32 216404B.32 216404B

VIBRATION ISOLATORS

SPRING ISOLATORS

Z&5

ORDERING

(877-j

216404B~27

216404B-28 216404B-28 216404B-31

2164048-31

__-

LOCATIONS

3&6

ORDERING

NUMBER

(877-i

216404B-28 216404B-28 216404B-27

216404B-27

216404B-31

216404B.31 216404B-32 216404B-32

TABLE 2

Page 6

ISOLATOR LOADS

Page 7

Page 8

WATER PIPING

Piping Practices Due to the variety of piping practices, it is advisable to follow

the recommendations of local authorities.

They can supply the in-

staller 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 perfor-

mance up.

Vibration eliminators to reduce vibration and noise transmission

It should contain:

to the building.

Shutoff valves to isolate the unit from the piping system dur-

2. ing unit servicing.

Manual or automatic air vent valves at the high points of the

system.

Some means of maintaining adequate system water pressure (e.g.; expansion tank or regulating valve).

Temperature and pressure indicators located at the unit to aid in unit servicing.

A strainer or some means of removing foreign matter 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.

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.

Chilled Water Thermostat

The chilled water thermostat is mounted inside the unit control center.

On models ALR-075A through

130A,

the thermostat sensor is fac-

tory mounted in the return water connection of the evaporator. On models

water line as shown in Figure 6.

ALR-060A

and

065A,,

the sensor must be installed in the return

The thermostat sensor should be in-

sulated after installation.

FIGURE 6

THERMOSTAT SENSOR

REDUCING BUSHING

THERMOSTAT SENSOR INSTALLATION

RETURN WATER CONNECTION OF EVAPORATOR

LRETURN WATER LINE

Page 8

Page 9

CAUTION:

Flow Switch

Thermostats have maximum operating temperature limits of:

ALR-060 and 065

140F on return water for standard ca-

pacity reduction.

125F on return water for optional capacity reduction. ALR-075 throuqh 130

125F on return water for standard capacity reduction.

250F on return water for optional ca-

pacity reduction.

Temperatures exceeding these limits may damage the controls.

WATER FLOW SWITCH

A ing water line to insure that there will be adequate water cooling load to the evaporator before the unit can start. safeguard against slugging the compressors on start up.

MUST

BE MOUNTED in either the entering

leav-

flow and

This will

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 860-

175033x-00.

size from to close the switch and are listed in Table 3.

It is a "paddle"

to 6" nominal.

type switch and adaptable to any pipe

Certain minimum flow rates are required

Installation

should be as shown in Figure 7.

TABLE

FLOW SWITCH MINIMUM FLOW RATES

NOMINAL

PIPE SIZE

(INCHES)

l/4

l/2

2112

5 6

MINIMUM REQUIRED

FLOW TO ACTIVATE

SWITCH

6.00

9.80

12.70

18.80

24.30

30.00

39.70

58.70

79.20

(GPM)

FIGURE 7

+ FLOW4

DIA.

5 PIPE

AFTER SWITCH

MINIMUM 5 PIPE DIA.-MINIMUM

FLOW DIRECTION

J’

MARKED ON SWITCH

1.00

NPT FLOW SWITCH

CONNECTION

BEFORE SWITCH

Electrical connections in the unit control center should be made at terminals 11 and 12. should be wired between these two terminals.

normally closed contacts on the switch that could be used for an in-

The normally open contacts of the flow switch

There is also a set of

dicator light or an alarm to indicate when a "no flow" condition

exists.

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Page 10

Piping Connections Water piping connections at the unit vary in size and style depen-

ding on the baffle option ordered.

These connection variations are

shown in the table with Figure 8.

Piping through the unit cabinet can be through the end or bottom of

the unit as the application dictates.

hole centers for piping through the end of the unit.

Pilot holes locate

Figure 8 gives

the proper

the necessary dimensions for either piping method.

FIGURE 8

ALR

r\,

060AD 192 80.0 73.8 36.1 16.3 33.7 24.0 065AD 192 80.0 73.8 36.1 16.3 33.7 24.0 075AD 228 98.8 92.5 47.0 8.0 76.0 30.0 91.4

*COOLER CONNECTIONS

Ail

connections

couplings by others.

DIMENSIONS (INCHES)

are NPS steel

Page 10

tib.1

pipe.

thru

6-inch

pipe

connections are

furnished

COOLER

with grooves for

victaulic

Page 11

Field Wirinq

FIELD WIRING

Wiring should be done in accordance with

all applicable codes and

ordinances.

Warranty

-Warranty is voided if wiring is not in accordance with specifica-

tions.

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

while either aluminum or copper can be used for all other wiring.

All unit sizes are set up as standard for separate 115 volt power

supply circuits for the control circuit and cooler heater.

The con-

trol circuit only or both the control circuit and cooler heater can

be powered off of the main unit power supply if the optional control

circuit transformer is ordered.

have the unit

the main unit

out defeating

cooler heater on a separate disconnect switch from

power supply so that the unit may be shut down with-

the freeze protection provided by the cooler heater.

It may be desirable, however, to

TABLE 4

Wire sizing ampacities and recommended power lead wire sizes

Notes: 1. Separate terminals provide for the field connection of a

separate

2. Wire sizing amps are equal to 125% of the Nameplate Amps of the largest motor plus 100% of the Nameplate Amps of all other loads in the circuit (the control circuit is not included). To include the control circuit, add 10 amps to 208 or 230 volt units and 5 amps to 460 volt units. Recommended power lead wire and maximum fuse sizes are not affected.

3. Recommended power lead wire sizes for three conductors per conduit are based on 100% conductor

115/60/1

power supply to the control circuit.

ampacity at 86 F ambient for no more than 3 conductors per conduit. Wire sizes for six conductors per conduit are based on 80% of the above mentioned conductor ampacity in accordance with NEC. Voltage drop has not been included, therefore, it is recommended that power

leads be kept short. All terminal block connections must

be made with copper wire.

The unit power terminal block has two lugs per phase. Single or parallel conductors per phase may be used for power hookup as listed under “Recommended Power

Lead Wire Size.” The cooler heater cable current draw is 3.5 amps.

Page 11

Page 12

Page 13

A standard feature on all ALR units is

COPSTM(Controlled

Override of

Pump Shutdown),a system for interlocking the field supplied chilled

water pump into the chiller control system.

A relay (R-19) is wired

into the unit control circuit so that a time clock and/or ambient thermostat can be connected to a pair of terminals (6 and 11) inside the unit control center. starter.

Once the pump starts,

The time clock can energize a pump

the flow switch and/or pump inter-

lock will close and energize that part of the control circuit that

will allow the unit to start.

This feature makes it possible to start the chilled water pump and the chiller simultaneously only when cooling is required.

For re-

cycling pumpdown without a demand for cooling, a pair of relays

(energized by low pressure controls) are also wired into this cir-

cuit to start the pump,

close the flow switch and pump down the

unit.

NOTE:

If a time clock,

ambient thermostat and/or re-

mote on-off switch are not used, terminals 6

and 11 must be jumpered together before the

unit will start.

Figure 9 shows typical field wiring that is required for unit installation.

FIGURE 9

TYPICAL FIELD WIRING DIAGRAM

Standard is separate power supply circuits for controls and cooler heater. These circuits may be combined by installing jumpers from terminals 1 NOTE C: Pump starter, contacts of R9, terminals 7 & 8 are limited to 250 volts maximum.

CUSTOMER CONNECTION FIELD WIRING FACTORY WIRING BLACK WIRING (LINE) WHITE WIRING (NEUTRAL)

flow switch and/or starter interlock.

9 & 10 - 20.

R10,

and

R19

between

START - UP AND SHUT DOWN

Pre Start-Up

With all electric disconnects open,

check all screw or lug type electrical connections to be sure they are tight for good electrical contact. fore shipment,

Although all factory connections are tight be-

some loosening may have resulted from shipping

vibration,

Inspect all water piping for flow direction and correct connections at the evaporator.

Page 13

Page 14

10.

Open all water flow valves and start the chilled water pump. Check all piping for leaks and vent the air from the evaporator as well as from the system piping. system piping to obtain clean,

orator circuit.

Check to see that the thermostat water temperature sensor is installed in the return water line (return to chiller).

075A through ALR-060A tion, and the sensor should be secured in the well with the retaining

clip provided. On ALR-075A through 130A units with optional cap-

acity reduction,the sensor is installed directly into the return water line i.e.;

Check the compressor oil level. Prior to start-up, the oil level should cover at least

Remove the (8) compressor shipping blocks that are attached to the

compressor rails and the base of the unit. not have shipping blocks. Check the voltage of the unit power supply and see that it is within the balance must be with _+ 2%. Check the unit power supply wiring for adequate ampacity and a minimum insulation temperature rating of 75C. Verify that all mechanical and electrical inspections have been

completed per local codes.

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

and 065A units with standard or optional capacity reduc-

the sensor well should be full of heat conducting

13OA

10%

units with standard capacity reduction, or

no well or heat conducting compound is required.

l/2

tolerance that is allowed.

non-corrosive water in the evap-

of the oil sight glass.

Flush the evaporator and

ALR-

compound

The ALR 060 and 065 do

Phase voltage un-

Start-Up

Open the compressor suction and discharge back seated.

Open the manual liquid line shutoff valve at the outlet of the subcooler.

Check to see that pumpdown switches

3. pumpdown"position and the control stop switch

"on

position.

Adjust the dial on temperature controller

chilled water temperature.

Throw the main power and control circuit disconnects to the "on"

5. position.

CAUTION:

Allow the crankcase heaters to operate for at least 8 hours prior to start-up.

Start the auxiliary equipment for the installation by turning

7. on the time clock,

if the unit and chilled water pump are electrically interlocked

by using the COPS

Start the system by moving pumpdown switches

"auto.

After system performance has stabilized, it

"Compressorized Equipment Warranty Form" (form no. 206036A) be

completed to obtain full warranty benefits.

with the unit and after completion should be returned to McQuay's

Service Department through your sales representative.

pumpdown" position.

Always replace valve seal caps.

(PSl &

Most relays and terminals in the unit control center are hot with control circuit

ambient thermostat and/or remote on/off switch

method discussed in "Field Wiring".

disconnect

shutoff valves until

PS2) are in the

(Sl)

is in the

TCl

to the desired

and the

on.

(PSl &

necessary that the

This form is shipped

PS2) to the

"man.

Page 14

Page 15

Temporary Shut-Down

Move pumpdown switches

After

pump.

It is important that the compressors pump down before the water flow

to the unit is interrupted to avoid freeze up in the evaporator.

Start-Up After Temporary Shut-Down

Extended Shut-Down

the compressors have pumped down, turn off the chilled water

NOTE:

Start the chilled water pump.

With control stop switch

down switches Observe the unit operation for a short time to be sure that the compressors do not cut out on low oil pressure.

Close the manual liquid line shutoff valves. After the compressors have pumped down, turn off the chilled water pump.

Turn off all power to the unit and to the chilled water pump. Move the control stop switch

Close the compressor suction and discharge valves.

Tag all opened disconnect switches to warn against start up be-

fore opening the compressor suction and discharge valves. Drain all water from the unit evaporator and chilled water pip-

ing if the unit is to be shut down during winter.

With the unit left in this condition, it is

capable of recycling pumpdown operation. To

defeat this mode of operation, simply move

control stop switch

(PSl &

(PSl

& PS2) to the "man. pumpdown" position.

(Sl)

to the "off" position.

(Sl)

in the

PS2) to the "auto. pumpdown" position.

(Sl)

to the "off" position.

"on"

position, move pump-

Start-Up After Extended Shut-Down

Inspect all auxiliary equipment to see that it is in satisfac-

tory operating condition.

Remove all debris that has collected on the surface of the condenser coils.

Open the compressor suction and discharge valves.

Open the manual liquid line shut off valves.

Check to see that pumpdown switches ual pumpdown position.

Turn on the electric power to the unit and other parts of the

system.

Allow the crankcase heaters to operate for at least 8 hours prior to start-up.

Start the chilled water pump and purge the water piping as well

as the evaporator in the unit.

Check to see that the control stop switch tion.

CAUTION:

Most relays and terminals in the unit

control center are hot with control circuit disconnect on.

(PSl

and PS2) are in the man-

(S1)is

in the

and the

"on"

posi-

Page 15

Page 16

10.

Start the unit by moving

pumpdown

switches

(PSl

& PS2) to the

"auto.pumpdown" position.

11.

After running the unit for a short time check the oil level in

each compressor crankcase and check for flashing in the refrigerant sight glass (see "Maintenance" on Page 47).

ELECTRICAL

Control Center

All electrical controls are enclosed in a weatherproof control cen-

ter with keylocked, hinged access doors.

posed of three separate enclosures.

The upper enclosure is the largest and contains all of the 208, 230, fan motor starting controls.

Also included in this enclosure but

partitioned separately are the exposed terminal type

ational controls.

A "dead front"

cover over the high voltage sec-

The control center is com-

or 460 volt compressor and

115 volt oper-

tion protects service personnel from high voltage starting controls

while servicing low voltage operational controls.

Below the upper enclosure are two smaller, contain 115 volt adjustable or resettable controls.

separate enclosures that

There is one of

these enclosures on each side of the unit, and each contains controls

for the compressors on that side.

Power supply conduits are intended to come into the bottom of the upper enclosure and between the two lower enclosures.

mended that the unit disconnect switch be mounted away but

Figure 10 recommends unit mounting arrangements if the disconnect

it is recomfrom the unit

must be unit mounted.

Page 16

Page 17

Page 18

ELECTRICAL LEGEND

-A--

---_

--CL

200

F1 F2

Ft31,2,3.4 FE5 FB11,12,13 FS1.2 HP1.2

HTRl,

HTR5 JB

LPI,2

LP Ml thru 8 Ml

1,12,13

MPI

thru 4

OP1,2,3,4 OP PBl

PC1 and PC2 TC5 and TC6

PS1.2 R3.4 R5,6,7.8 R9.10

R13.14 R15, 16

R17.18

RI9

S2,3,4

Tl TD1,2,3,4 TD5.6,7.8 TD9,lO TD11,12,13

NB1.2 TB6,7 TB5.8.9 TCl

SC1

TC2

thru 4

FIELD WIRING AND NUMBERED TERMINAL OPTIONAL WIRING

FACTORY WIRING AND NUMBERED TERMINAL

WIRE NUMBER OPTIONAL CONTROLS CONNECTER ALARM BELL CONTROL CIRCUIT FUSE EVAPORATOR HEATER FUSE FUSE BLOCKS (COMP. CONTROL CIRCUIT TRANSFORMER FUSE BLOCK - OPTIONAL FUSE BLOCKS (COND. FAN FREEZE CONTROLS (REF. CIRCUIT HIGH PRESSURE CONTROLS (REF. CIRCUIT HIGH PRESSURE GAUGE -OPTIONAL CRANKCASE HEATERS (COMP. EVAPORATOR HEATER

JUNCTION BOX (FOR ALARM BELL)

LOW PRESSURE CONTROLS (REF. CIRCUIT

LOW PRESSURE GAUGE -OPTIONAL CONTACTORS (COMP. CONTACTORS (COND. FAN

MOTOR PROTECTORS (COMP. OIL PRESSURE CONTROLS (COMP. 01

L PRESSURE GAUGE - OPTIONAL MAIN POWER TERMINAL BLOCK FANTROL PRESSURE CONTROLS

FANTROL TEMPERATURE CONTROLS PUMPDOWN STARTER RELAYS (COMP. SAFETY RELAYS (COMP.

LOW PRESSURE RELAYS (REF. CIRCUIT

LOW AMBIENT START RELAYS (REF. CIRCUIT COMPRESSOR LOCKOUT RELAYS

CONDENSER FAN RELAY PUMP STARTER RELAY CONTROL STOP SWITCH LEAD-LAG SWITCHES CONTROL CIRCUIT TRANSFORMER PART WINDING TIME DELAYS (COMP.

COMP. LOCKOUT TIME DELAYS (COMP. 1,2,3,4)

LOW AMBIENT START TIME DELAYS (CIRCUIT 1,2)

COMP. SEQUENCING TIME DELAYS (STAGES TERMINAL BLOCKS (NEUTRAL-FACTORY WIRING) TERMINAL BLOCKS (HOT-FACTORY WIRING) TERMINAL BLOCKS (FIELD WIRING) WATER TEMP. CONTROL THERMOSTAT OPTIONAL WATER TEMP. CONTROL THERMOSTAT SIGNAL CENTER OPTIONAL WATER TEMP. CONTROL THERMOSTAT TRANSFORMER

ALARM BELL TRANSFORMER COOLER HEATER THERMOSTAT

SWITCHES (REF. CIRCUIT 1.2)

SEE WI RING DIAGRAMS

1,2,3,4)

11,12,13)

1,2,3,4)

11,12,13)

3,4)

1,2,3,4)

1,2)

1,2,3,4)

OPTIONAL

1,2,3,4)

OPTIONAL

1,2)

1,2,3,4)

1,2)

-OPTIONAL

OPTIONAL

2,3,4)

Sequence of Operation

The following sequence of operation is typical for ALR Seasonpak air cooled water chiller operation.

unit,

referred pressors

but where components that apply to the fourth compressor are

the equivalent components for the third and second

to,

of a 3 or 2 compressor unit are

It is written for a 4 compressor

indicated in parentheses.

Page 18

com-

Page 19

With the control circuit power on,

and manual pumpdown switches 115 volt power is applied through control circuit fuse compressor crankcase heaters also to the contacts of low pressure switches

PSl

HTRl

control stop switch

and PS2 closed ("Auto" position),

through HTR4,

(HTR3,

LPl

and LP2.

closed,

to the

HTR2,) and

When the remote time clock or manual shutdown switch turns "on",

pump starter relay

the chilled water pump. thermostatic circuit also close. With the flow switch closed, if freeze controls FSl and 2,

pressor motor protectors MPl through MP4 (MP3,

alarm condition,safety relays applying power to the water temperature controller

operate automatically in response to

On a call for cooling, gizes liquid line solenoid valve

refrigerant to flow into the evaporator.

builds up,

relay compressor number 1.

denser fan relay R17,

condenser fan motor contactors

units,

If additional stages of cooling are required, temperature control thermostat

delay relay TDll has sequenced closed,

sequence in refrigerant circuit number 2.

low pressure control

which closes to energize compressor contactor Ml, starting

Mll,

TCl

energizes liquid line solenoid valve SV2 after time

R19

is energized,

Relay

the temperature control thermostat

Closing relay closing its contacts and providing power to

12 on 2 compressor units.

R19,

high pressure controls HP1 and 2 and com-

LPl

Mll,

closing contacts 1 and 3 to start

contacts 4,

through R8 (R7,

TCl.

SVl,

opening the valve and allowing

closes,

contacts also energizes con-

12 & 13 on 3 & 4 compressor

6, 7 and 9 in the

MP2)

do not sense an

R6)

are energized

TCl.

As refrigerant pressure

energizing low pressure

to initiate the same starting

The unit will

TCl

ener-

COPSTM

On 3 and 4 compressor units, the third and fourth stages of temperature control thermostat

energize the third and fourth compressors after time delay relays TD

TD13

12 and

Pumpdown Cycle

As temperature control thermostat

contacts, valve to close. gerant from the evaporator to the condenser, LPl

opens,

Should a closed solenoid valve allow refrigerant to leak to the low

side of the refrigerant circuit during unit "off"

in pressure will cause the low pressure control to close, energizing the low pressure relay and starting the compressor for pumpdown.

have sequenced closed.

de-energizing liquid line solenoid valve

When the compressor has pumped most of the refri-

shutting down the compressor and condenser fan motors.

if additional cooling is still required

TCl

is satisfied, it opens its

SVl,

causing the

the low pressure control

time,

the buildup

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Page 41

High Pressure Control The high pressure control is a single pole pressure activated switch

that opens on a pressure rise to de-energize the entire control circuit except for compressor crankcase heaters and the cooler heater.

It senses condenser pressure and is factory set to open at 380 PSIG and can be manually reset closed at 315 PSIG.

To check the control,

either block off condenser surface or start the unit with fuses in

only one fan fuse block

(FB11)

control by watching condenser pressure rise.

and observe the cut-out point of the

The highest point reached before cut-out is the cut-out setting of the control. CAUTION:

Although there is an additional pressure relief device in

the system set at 425 PSIG,it is highly recommended that the "control

Stop"

switch

(S1)

be close at hand in case the high pressure control

should malfunction.

Low Pressure Control

The low pressure control is a single pole on a pressure rise.

It senses evaporator set to close at 60 PSIG and automatically the control (unit must be running),

move the pumpdown

and PS2) to the "man. pumpdown" position.

down

condenser pressure will rise and evaporator pressure will drop.

pressure switch that closes pressure and is factory open at 35 PSIG.

To check

switch(es) (PSl

As the compressor pumps

The lowest evaporator pressure reached before cut-out is the cut-out

setting of the control. to the "auto. pumpdown" position,

By moving the pumpdown

evaporator pressure will rise.

switch(es) (PSl &

PS2)

The highest evaporator pressure reached before compressor re-start is the cut in setting of the control.

Freeze Control

LINE (SEE NOTE

LINE (SEE NOTE 2)

NOTES: 1. Hot whenever unit compressor(s) is running.

CONTACT

2. Hot whenever control circuit flow stop switch

3. Provides power to energize compressor contactors through low pressure relay

(S1)

are closed.

L M

(R9

BIMETALLIC CONTACT

switch

and control

R10).

NEUTRAL

HEATER ELEMENT

LINE (SEE NOTE 3)

The freeze control is very similar to the oil pressure control in operation except that it senses evaporator pressure only rather than

a pressure differential.

It contains a pressure actuated contact

that upon a fall in evaporator pressure energizes a heater element

that in turn opens a normally closed bimetallic contact.

bimetallic contact opens,

it de-energizes the entire control circuit

except for the compressor crankcase heaters and cooler heater.

When the

The control is factory set to close at 52 PSIG and open at 54 to 57 PSIG. It takes approximately 60 seconds to warm the heater element enough

to open the bimetallic contact.

This time delay period prevents

nuisance cutouts due to a momentary drop in suction pressure, but

since the control senses pressure rather than temperature, it still

provides quicker response for protection than a temperature sensing

control.

Page 41

Page 42

To check the control,

be connected across terminals of the pressure activated contact.

the unit running, terminals.

(PSl

and PS2) to the "manual pumpdown" position. Evaporator pressure

will begin to drop.

vated contacts of the control will have closed.

pressure at which this happens.

down before the 60 second delay period, not open before the unit shuts down.

tion may be checked after the pumpdown cycle is complete by connecting a

jumper

control. that evaporator pressure is sufficiently low. the bimetallic contacts of the control should open.

Should the control(s) cause the unit to shut down during normal operation,

bimetallic contacts of the control will have cooled enough to allow

the control to be manually reset. ty control, prolong the time required before reset.

from terminal 1 in the control center to terminal T2 of the

Observing evaporator pressure,

This will energize the heater element of the control provided

a period of about 2 minutes will be required before the

repeated successive operations of the freeze control will

the system must be operating.

there should be a 115 volt potential across these

move the pumpdown

When the voltmeter goes to zero, the pressure acti-

Because the unit will have pumped

bimetallic contacts L

This part of the control opera-

Within about

Similar to the oil pressure safe-

A voltmeter should

switch(es)

Note the evaporator

M will

seconds,

With

Fantrol

Fantrol is a system for progressively turning on or off condenser

fans when they are no longer required.

denser capacity (typically in low outdoor ambient temperatures) and

is accomplished by a combination of pressure and temperature actu-

ated controls.

when the first compressor in the unit starts.

12) is controlled by a pair of parallel wired pressure switches, one of which senses condenser pressure in refrigerant circuit No.1 and one which senses pressure in circuit

13-3 fan units only) is controlled by a pair of parallel wired tem-

perature switches,

ture for refrigerant circuit No.1 and one for circuit

and temperature control set points are indicated below.

Head Pressure Control

The first fan (No.

one of which senses condenser air inlet tempera-

This is done to reduce con-

11) is started by its contactor The second fan (No.

No.2.

The third fan (No.

No.2.

-1

* No.

fan 13 on 060 and 065 unit.

To check the cut-in points of the controls, the unit must initially

be off.

cedures outlined in this bulletin, to the "auto. pumpdown" position. rise and the compressor(s) should start with fan No. 11 starting

immediately. pressure as it rises. mately 270 PSIG,

On 3 fan units, fan No.

the ambient air at the condenser inlet reaches 80F.

Page 42

With the unit prepared for start up according to the pro-

move pumpdown switches

Evaporator pressure will begin to

After the compressor(s) starts, observe condenser

When the condenser pressure reaches approxi-

contactor Ml2 should pull in to start fan No. 12.

13 should start via contactor Ml3 whenever

Pressure

(PSl &

PS2)

Page 43

It may be difficult to check the cut-out point of fan No. 13 (on 3 fan units) at the instant it happens, the ambient air at the condenser inlet is below 70F. cut-out point of fan No. 12,

unit must be

available or the fan operation and condenser pressure(s)

some means of reducing the load on the

must be observed as the load drops off naturally.

but it should be off whenever

To check the

When the conden-

ser pressure drops to approximately 170 PSIG, contactor Ml2 should

drop out to turn off fan No. 12.

Dampertrol

Optional Head Pressure Control

DAMPERTROL IN OPEN POSITION

DAMPER SECTION

UNIT CONDENSER

DAMPER SECTION

CONDENSER

DAMPERTROL IN BYPASS POSITION

Dampertrol is also a system for reducing condenser capacity when it is not required.

It consists of an assembly of damper blades, link-

ages and blade operators installed over the first fan turned on by

Fantrol (Fan No.

11) and arranged to operated as shown above.

The

blade operators sense condenser pressure and extend or contract in

response to that pressure to open or close the damper blades as re-

quired to maintain adequate condenser pressure.

factory set to begin opening the damper blades at 170

The operators are

5 PSIG and

to be fully open at 250 _+ 10 PSIG.

To check the damper blade operator pressure settings, the unit should be started with the fuses removed from fans 11 and 13 (on 3 fan units only).

should be completely closed.

At condenser pressures below 170 2 5 PSIG, the damper blades

As pressure rises above 170

5 PSIG,

the damper blades should begin opening and be fully open at 250 +

10 PSIG, leaving the fuses in on fan 12 will prevent head pressure

from becoming excessive since this fan will start after the fully

open setting of the damper operators has been observed.

Page 43

Page 44

Part Windinq Start

LINE

Optional

PART WINDING

;;;I

NOTE: Line

only hot when the unit thermostat calls for compressor to run

COMPRESSOR CONTACTOR

(2nd

MOTOR WINDING)

Part winding start is available on all voltage units and consists of a solid state time delay wired in series with the contactor that ener-

gizes the 2nd winding of each compressor motor.

limit current in-rush to the compressors upon start up.

Its purpose is to

As each com-

pressor starts,the contactor for the first motor winding is energized

instantly while that for the second motor winding is delayed for 1 second.

Control checkout is best accomplished by observation as each contactor is pulled in to see that the 1 second delay occurs before the

second contactor pulls in.

Low Ambient Start

Optional

NOTE :

Line is only hot when the unit thermostat calls for compressor to run

Low ambient start is available on all units as an option with Fantrol and included automatically with optional Dampertrol or Seasontrol. It consists of a solid state normally closed time delay wired in series with a relay.

These are both wired in parallel to the liquid

line solenoid valve so that when the solenoid valve is energized by

the unit thermostat,

through the time delay.

the low ambient start relay is also energized

The relay has contacts that essentially

short circuit the low pressure control and allow the compressor to

start with the low pressure control open.

3/4

After about 2

the relay.

If the system has not built up enough evaporator pressure

to close the low pressure control,

minutes,

the time delay will open and de-energize

the compressor will stop.

The

time delay can be reset to its original normally closed position by moving the pumpdown position.

Moving the pumpdown switch back to the "auto. pumpdown"

switch(es) (PSl

or PS2) to the "man. pumpdown"

position will again energize the relay for another attempt at start up.

If the system has built up enough evaporator pressure, the com-

pressor will continue to run.

Page 44

Page 45

To check the control,

wire(s) (No.113

LP2) from terminal 4 in the unit control center.

turn off all power to the unit and remove the

213) leading to the low pressure control(s) Remove the com-

(LPl

pressor fuses and jumper across terminals L & M of the freeze con-

trol(s) and oil pressure safety control(s).

Energize the control circuit by turning on the control circuit disconnect or main power disconnect (depending on the installation) and the control stop

switch

After about 2

Sl.

The compressor contactors should pull in instantly.

3/4

minutes they should drop out again.

Compressor Lockout - Optional

LOW PRESSURE

MI AUX.

NOTE)

NOTE:

Hot whenever freeze control and high pressure con

trol permit safe

I’ ‘2

TO UNIT THERMOSTAT

operation

RI5

I I

II 13

COMI?

LOCKOUT

TIME DELAY

COMPRESSOR

NEUTRALS

Compressor lockout consists of a solid state time delay wired in series with the compressor contactor( rapid compressor cycling when cooJ_ing demands are erratic.

Its purpose is to prevent

The circuit illustrated above is for the lead compressor in each refrigerant circuit. The circuit for the second compressor(s) performs the same function but is wired differently (see unit wiring diagram).

When the unit thermostat no longer calls for cooling and the com-

pressor contactor have opened,

the lockout time delay breaks open

the circuit preventing compressor re-start.

The circuit remains open for a period of 5 minutes so that if the

unit thermostat should call for cooling before the delay period has

expired,

the compressor will not re-start.

After 5 minutes, the

time delay will close its contacts to complete the circuit and be

ready for start up.

The time delay opens its contacts whenever power to terminal 4 is interrupted and resets closed automatically after the time delay period.

To check the control,the compressor(s) must be running initially.

(PSl

Move the

tion.

pumpdown switch

Immediately after the compressor(s) have stopped running,

move the pumpdown switch back to the "auto. pumpdown" position.

lead compressor should not re-start for 5 minutes.

pressor in the

onds after the high enough to

refrigerant circuit should start approximately 20 lead compressor, require it.

or PS2) to the "man. pumpdown" posi-

The

The second com-

sec-

provided that the cooling load is

Each refrigerant circuit can be checked

the same way.

Page 45

Page 46

Alarm Bell - Optional

The 24 volt alarm bell is mounted inside the control center but not

wired to the control circuit.

It is expected that in most cases,

the customer will want to relocate the bell where it will be more easily heard in the event of a safety failure.

There are leads for

connection of the bell inside a junction box which is located in the

unit control center.

All that is necessary is that the bell be mounted in a preferred location and wired to the leads in the junction box.

The bell is wired into the control circuit so that it will sound

whenever there is a failure due to low oil pressure, motor overload,

an evaporator freeze condition,

or excessive condenser pressure.

Hot Gas Bypass

HOT GAS BYPASS PIPING DIAGRAM

Solenoid Valve

Bypass Valve

Optional

External Equalizer Connection to Suction

Side of Evapoator

Expansion Valve

Remote Bulb

HOT GAS BYPASS ADJUSTMENT RANGE

REMOTE BULB ADJUSTMENT RANGE

30 40

TEMP

(OF) AT BULB

LOCATION

100

110

Hot gas bypass is a system for maintaining evaporator pressure at or above a minimum value.

The purpose for 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 con-

ditions are light.

The system consists of a solenoid valve piped in series with a pressure regulating valve as shown above.

The solenoid valve is factory

wired to open whenever the unit thermostat calls for the first stage

of cooling.

opening at 58 PSIG (32 F for R-22)

a 80 F.

ambient temperature.

The pressure regulating valve is factory set to begin

when the air charged bulb is in

Since the bulb is factory mounted on the suction line and suction line temperatures are usually in the 50F. to 60F range,

the chart above indicates that for ALR chillers, the valve is factory set to begin opening at 54 to 56 PSIG. setting can be changed as indicated above by changing the pressure of the air charge in the adjustable bulb. setting,

clockwise.

remove the cap on the bulb and turn the adjustment screw

To lower the setting,

turn the screw counter-clockwise.

To raise the pressure

Do not force the adjustment beyond the range it is designed for as

this will damage the adjustment assembly.

Page 46

This

Page 47

The regulating valve opening point can be determined by slowly reducing the system load (or increasing the required chilled water temperature setting indicated on the unit thermostat), while observing

the suction pressure.

frigerant line on the evaporator side of the valve will begin to

feel warm to the touch.

CAUTION:

General

The hot gas line may become hot enough to cause injury in a very short time so care should be taken during valve checkout_

When the bypass valve start to open, the re-

UNIT MAINTENANCE

CAUTION:

On initial start up and periodically during

ation it will be necessary to perform certain routine service checks.

Among these are checking the compressor oil level and taking conden-

sing, level should be visible in the oil sight glass with the compressor running.

pressures can be read from the unit control center.

factory installed with a manual shut off valve on each gauge line.

The valves should be closed at all times except when gauge readings

are being taken.

off valves come factory installed inside the unit control center for

convenient connection of service gauges from outside the unit. Refriqerant

The refrigerant sight glasses should be observed periodically. (a monthly observation should be adequate.)

indicates that there is adequate refrigerant charge in the unit to

insure proper feed through the expansion valve. ant in the sight glass indicates that the unit is short of refrigerant charge. moisture. moisture condition corresponds to a given element color.

sight glass does not indicate a dry condition after a few hours of operation the unit should be pumped down and the cores in the driers changed.

Disconnect all power before doing

suction,

On units ordered with gauges,

and oil pressure readings.

On units ordered without gauges, the gauge shut

Siqht

A color key on the face of the sight glass indicates what

Glass

An element inside the sight glass is sensitive to

any service inside the unit.

operation after install-

During operation, the oil

condensing suction and oil

The gauges are

A clear glass of liquid

Bubbling refriger-

If the

filter-

Filter-Driers To change the filter drier core(s),

pumpdown switches Turn off all power to the unit and install jumpers from terminals

21 to 24 and 41 to 44. the unit by moving pumpdown switches down" position.

when evaporator pressure reaches 0 PSIG, move the control stop

switch solenoid valve(s) and isolate the short section of refrigeration piping containing the filter-drier(s). the filter-drier shell and replace the

After core replacement, round the flange of the filter-drier cores have been changed.

(Sl)

to the "off" position.

(PSl &

Close the manual liquid

PS2) to the "man. pumpdown" position.

Turn power to the unit back on and re-start

replace the cover plate. A leak check a-

pump

This will close the liquid line

the

(PSl &

line

Remove

core(s).

shell

is recommended after the

unit down by moving

PS2) to the "auto. pump-

shutoff valve(s) and

the cover plate from

Page

Page 48

Liquid Line Solenoid Valve

The liquid line solenoid valves,which are responsible for automatic pumpdown during normal unit operation,do not normally require any

maintenance.

They may, however,require replacement of the solenoid

coil or of the entire valve assembly.

The solenoid coil may be removed from the valve body without opening the refrigerant piping by moving pumpdown switches the

"man.

pumpdown" position.

The coil can then be removed from the

(PSl & PS2)

valve body by simply removing a nut or snap ring located at the top

of the coil. replacement. fore returning pumpdown switches

The coil can then be slipped off its mounting stud for

Be sure to replace the coil on its mounting stud be-

(PSl &

PS2) to the "auto. pumpdown"

position.

To replace the entire solenoid valve,

use

the manual liquid line valve.

the unit must be pumped down by

Thermostatic Expansion Valve

INLET

HYDRAUL BETWEEN

POWER ELEMENT

(CONTAINS DIAPHRAGM)

ADJUSTMENT SCREW

CAP

FILL

.IC

APHRAMS

The expansion valve is responsible for allowing the proper amount of refrigerant to enter the evaporator regardless of cooling load. It does this by maintaining a constant superheat.

(Superheat is the difference between refrigerant temperature as it leaves the evaporator and the saturation temperature corresponding to the evaporator

pressure.)

superheat. the valve,

adjustment screw.

All ALR chillers are factory set for between 8F and

If it is necessary to increase the superheat setting of

remove the cap at the bottom of the valve to expose the

Turn the screw clockwise (when viewed from the

adjustment screw end) to increase the superheat setting and counter-

clockwise to reduce superheat.

Allow time for system rebalance af-

ter each superheat adjustment.

Page 48

12F

Page 49

The expansion valve, require replacement, but if it does, using the manual liquid line shutoff traced to the power element only,

like the solenoid valve, should not normally

the unit must be pumped down by

valve.

If the problem can be

it can be unscrewed from the valve

body without removing the valve but only after pumping the unit down

with t

manual liquid line shutoff valves.

Evapor

atorr

TOP VIEW OF TYPICAL DUAL CIRCUIT

SHELL AND TUBE EVAPORATOR

TER BAFFLES

ATER NOZZELS

TUBE SHEETS

HEAD RINGS

LIQUID CONNECTIONS

SUCTlOhl

CONNECTION

The evaporator is of 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 refrigerant through the tubes.

Normally no service work is required on the evaporator. There may be instances where a tube will leak refrigerant into the water side of the system.

leak.

ends.

the problem can best be solved by plugging the tube at both

When the tube must be replaced, the old tube can be removed

In the cases where only one or two tubes

and replaced.

To remove a tube,

ing pumpdown switches

the unit should be temporarily pumped down by mov-

(PSl &

PS2) to the "man. pumpdown" position. Power to the unit should be shut off to install jumpers from terminals 21 to 24 and 41 to 44.

Turn power to the unit back on the pump down both refrigerant circuits until evaporator pressure is at or near 0 PSIG by closing the manual liquid line shutoff valves at the outlet of each condenser.

turning the valve stems clockwise.

Close both compressor suction valves by

These steps will insure

mini-

mum amount of refrigerant loss when the evaporator is opened up.

The tubes are mechanically expanded into the tube sheets (see sketch above) at each end of the cooler. is necessary to break this bond by collapsing the tube. this at both ends of the shell,

ment.

The new tube can then be inserted and re-expanded into the

In order to remove the tubes it

After doing

the tube can be removed for replace-

tube sheet.

Page 49

Page 50

NOTE:

The bond produced by expansion must be refrigerant tight. rolling the tube into the tube sheet.

This bond must be produced by

After re-assembling the evaporator,

should be introduced by momentarily opening the manual liquid line

valve.

Tube removal can only take place after the leaking tube is located. This

that would work would be to subject each tube to air pressure by

plugging each end,

end plugs observe to see if there is a loss of air pressure over a period of a minute or two.

Condensers Condensers are air cooled and constructed with

bonded in a staggered pattern into rippled aluminum fins. tenance is ordinarily required except the occasional removal of dirt and debris from the outside surface of the fins. not to damage the fins during cleaning.

Compressor Wear and Lead-Lag

A leak check should then be performed on the evaporator.

aspect depends on the ingenuity of the serviceman.

and with a pressure

Note:

The evaporator should always be supplied with clean water to minimize scale build up on the refrigerant tubes.

a small amount of refrigerant

One method

gauge

attached to one of the

3/8

O.D. copper tubes

No main-

Care should be taken

standard

for reversing the sequence that compressors start in. the hot gas bypass option do not have lead-lag.) compressor unit with the lead-lag switches in the "circuit 1 leads" position,

lag switches in the "circuit 2 leads" position, the reversed starting

sequence is 2, 1, 4,

It is achieved electrically bu a multi-pole switching arrangement (see Control Schematics on Pages 22 through 45.

lead lag switches in the unit control center be switched annually to provide long compressor life.

Compressor Oil Level Because of the large refrigerant charge required in an air cooled con-

densing unit it is usually necessary to put additional oil into the

system. up and for sometime thereafter.

At the present time,

land for use in these compressors. at about the midpoint of the sight glass on the compressor body.

Fan Belt Tension Check the belt tension after the first 48 hours of operation.

time the belts should have acquired their permanent stretch and further adjustments should not be necessary.

recheck the belt tension every 3 months.

feature on all McQuay ALR air cooled chillers is a system

(Chillers with

For example, on a 4

the normal starting sequence is 1, 2, 3, 4.

3 (see Component Location Diagram on Page 20).

It is suggested that the

The oil level should be watched carefully upon initial start

Suniso

#3GS

oil is the only oil approved by

The oil level should be maintained

However it is advisable to

With the lead-

Cope-

By this

Fan Shaft Bearings The fan shaft bearings do not require lubrication at the time the unit

is put into service. year using STANDARD OIL COMPANY AMCO Multi-Purpose Lithium Grease.

DO NOT OVERLUBRICATE.

Page 50

The fan shaft bearings should be greased once a

Page 51

Fan Motor Bearings

All fan motors are ball bearing,

addition of grease at the time of installation.

pre-lubricated and do not require the

Periodically, the ball

bearings should be cleaned and the grease renewed, to gain the ultimate in service from the motor bearings.

Extreme care must be exercised to prevent foreign matter from entering the ball bearings.

It is also important to avoid overgreasing.

Only

a high grade clean mineral grease having the following characteristics should be used.

Consistency: A little stiffer than that of Vaseline,

maintained over the operating temperature range; melting point prefer-.,'

ably over 150C

(302OF);

freedom from separation of oil and soap under

operating and storage conditions and freedom from abrasive matter, acid,

alkali and moisture.

Specific greasing instructions are to be found on the label attached to the unit and should be generally followed.

Electrical Terminals CAUTION!

ELECTRIC SHOCK HAZARD, TURN OFF ALL POWER BEFORE

CONTINUING

WITH FOLLOWING SERVICE. All power electrical terminals should be retightened every

as they tend

to loosen in service due to normal heating and cooling at

6 months,

the wire.

IN WARRANTY RETURN MATERIAL PROCEDURE

;

1, i

/ (1

COMPRESSOR:

who maintain

Copeland Refrigeration Corporation has stocking wholesalers a stock ofreplacement compressors and service parts to

serve refrigeration contractors and servicemen as required.

When a compressor fails in warranty,

the inoperative compressor can be taken to any authorized Copeland Wholesaler for an over-the-counter exchange or an advance replacement can be obtained.

Credit is issued on the returned compressor upon receipt and factory inspection of the inoperative compressor.

pressor is definitely defective.

field that tests satisfactorily,

In this transaction,

If a compressor is received from the

a service charge plus a transportation

be certain that the com-

charge will be charged against its original credit value.

On all out-of-warranty compressor failures,

Copeland offers the same

field facilities for service and/or replacement as described above. The credit issued on the returned compressor will be determined by the repair charge established for that particular unit.

COMPONENTS OTHER THAN COMPRESSORS

cept by permission of authorized factory service personnel of

Inc. with the returned material.

at Mpls., Minn. A "Return Goods"

Enter the information as called for on the

Material may not be returned ex-

McQuay,

tag will be sent to be included

tag in order to expedite handling at our factories and prompt issuance of credits.

The return of the part does not constitute an order for replacement. Therefore, McQUAY Representative.

a purchase order must be enetered through your nearest

The order should include part name, part number,

model number and serial number of the unit involved. Following our personal inspection of the returned part, and if it is

determined that the failure is due to faulty material or workmanship,

credit will be issued on customer's purchase order. All parts shall be returned to the pre-designated McQUAY factory, trans-

portation charges prepaid.

Page 51

Page 52

TROUBLE SHOOTING CHART

PROBLEM

Compressor will not run.

Compressor noisy or vibrating.

High Discharge

Pressure

Low Discharge

Pressure.

High Suction

Pressure

Low Suction

Pressure

Compressor wi not unload or load up.

Compressor

Loading - Unloading Intervals too short

Little or no

oil pressure.

Compressor loses oil.

Motor overload relays open or fuses blown.

Compressor thermal Protector Switch open.

Freeze protection opens.

ll l

POSSIBLE CAUSES

1. Main switch open.

2. Fuse blown.

3. Thermal overloads tripped or fuses blown.

4. Defective contactor or coil.

5. System shut down by safety devices.

6. No cooling required.

7. Liquid line solenoid will not open.

8. Motor electrical trouble.

9. Loose wiring

Flooding of refrigerant into crankcase.

2. Worn compressor.

1. Dirty tube and fin surface condenser).

2. Non-condensibles in system.

3. System overcharged with refrigerant.

4. Discharge shut off valve partially closed.

Faulty condenser temperature regulation.

2. Suction shutoff valve partially closed.

3. Insufficient refrigerant in system.

4. Low suction pressure.

5. Compressor operating unloaded.

6. Low ambient controls not set properly.

1. Excessive load.

2. Expansion valve overfeeding.

3. Compressor unloaders open.

1. Lack of refrigerant.

2. Evaporator dirty.

3. Clogged liquid line filter-drier.

4. Clogged suction line or compressor suction gas strainers.

5. Expansion valve malfunctioning.

6. Condensing temperature too low.

7. Compressor will not unload.

8. Insufficient water flow.

1. Defective capacity control.

2. Unloader mechanism defective.

3. Faulty thermostat stage or broken capillary tube.

4. Stages not set for application.

Erratic water thermostat.

2. Insufficient water flow.

Clogged suction oil strainer.

2. Excessive liquid in crankcase.

3. Oil pressure gauge defective.

4. Low oil pressure safety switch defective.

5. Worn oil pump.

6. Oil pump reversing gear stuck in wrong position.

7. Worn bearings.

8. Low oil level.

9. Loose fitting on oil lines.

10. Pump housing gasket leaks.

11.

Flooding of refrigerant into crankcase.

1. Lack of refriaerant.

2. Excessive

Low voltage during high load conditions.

2. Defective or grounded wiring in motor or power circuits.

3. Loose power wiring.

4. High condensing temperature.

5. Power line fault causing unbalanced voltage.

6. High ambient temperature around the overload relay.

7. Failure of second starter to pull in on winding start systems.

1. Operating beyond design conditions.

2. Discharge valve partially shut.

3. Blown valve plate gasket.

1. Thermostat set too low.

2. Low water flow.

3. Low suction

compression

pressure.

(air

cooled

ring blow-by.

part-

POSSIBLE CORRECTIVE STEPS

2. Check electrical circuits and motor winding for shorts or

3. Overloads are auto. reset. Check unit closely when unit

4. Repair or replace.

5. Determine type and cause of shutdown and correct it.

6. None. Wait until unit calls for cooling.

7. Repair or replace coil.

8. Check motor for opens, short circuit or burn-out.

9. Check all wire junctions. Tighten all terminal screws.

1. Check setting of expansion valve.

2. Replace.

2. Purge the non-condensibles.

3. Remove excess.

4. Open valve.

2. Open valve.

3. Check for leaks. Repair and add charge.

4. See below for Corrective Steps for low suction pressure.

5. See below for Corrective Steps for failure of compressor

6. Reset controls.

1. Reduce load or add additional equipment.

2. Check remote bulb. Regulate superheat.

3. See Corrective Steps below for failure of compressor

1. Check for leaks. Repair and add charge.

2. Clean chemically.

3. Replace

4. Clean strainers.

5. Check and reset for proper superheat. Replace if necessary.

6. Check means for regulating condensing temperature.

7. See Corrective Steps for failure of compressor to unload.

8. Adjust gpm.

1. Replace.

2. Replace.

3. Replace

4. Reset thermostat setting to fit application.

1. Replace.

2. Adjust gpm.

1. Clean.

2. Check crankcase heater. Reset expansion valve for higher

3. Repair or replace. Keep valve closed except when taking

4. Replace.

5. Replace.

6. Reverse direction of compressor rotation.

7. Replace compressor.

8. Add oil.

9. Check and tighten system.

10. Replace gasket.

11. Adjust thermal expansion valve.

1. Check for leaks and repair. Add refriaerant.

2. Replace compressor.

1. Check supply voltage for excessive line drop.

2. Replace compressor-motor.

3. Check all connections and tighten.

4. See Corrective Steps for high discharge pressure.

5. Check supply voltage. Notify power company. Do not

6. Provide ventilation to reduce heat.

7. Repair or replace starter or time delay mechanism.

2. Open valve.

3. Replace gasket.

1. Reset to 400F or above.

2. Adjust gpm.

3. See “Low suction pressure”.

switch.

grounds. Investigate for possible overloading. Replace fuse after fault is corrected.

comes back on line.

before resetting safety switch.

Clean.

Check condenser control operation.

to load up.

cartrrdgefs).

superheat. Check liquid line solenoid valve operation. readings.

start until fault is corrected.

Add facilities so that conditions are within allowable limits

FORM 339274Y REV. A

McQuay ALR-060A Installation Manual

TABLE OF CONTENTS

INTRODUCTION

NOMENCLATURE

PRE-INSTALLATION

Handling

INSTALLATION

Location

Access for Servicing

VIBRATION ISOLATORS

WATER PIPING

Chilled Water Thermostat

Flow Switch

FIELD WIRING

START - UP AND SHUT DOWN

ELECTRICAL

Control Center

ELECTRICAL LEGEND

Sequence of Operation

Pumpdown Cycle

General

UNIT MAINTENANCE

Liquid Line Solenoid Valve

Thermostatic Expansion Valve

Compressor Wear and Lead-Lag

Fan Motor Bearings

IN WARRANTY RETURN MATERIAL PROCEDURE

TROUBLE SHOOTING CHART