McQuay WHC Installation Manual

Bulletin No. IM 127 Rev.

November 1973

INSTALLATION AND

MAINTENANCE DATA

WHC

CENTRIFUGAL WATER CHILLER

145 THRU 362 TONS

McQUAY-PERFEX

INC. l 13600 INDUSTRIAL PARK BLVD., P.O. BOX 1551

MINNEAPOLIS, MINNESOTA 55440

l PHONE: (612) 545-2892

Controls

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Sequence of Operation...................................1 5

Set Points

Wiring Diagram

Charging

Dimensional Data

Electrical

Auxiliary Interlocks Motor Data

Power Wiring

Electronic Control

Operation

Calibration Evacuation Leak Tests Liquid Flow Control Location Motor Cooling Moving and Mounting Oil System

Physical Data Pre-Installation Pre-Startup Pressure Drop-Evaporator Pressure Drop-Condenser Shutdown Startup

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Trouble Shooting Vane Control

Warranty Information

Water Piping

Chilled Water Condenser Water Oil Cooler System Schematic

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..ti

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..12

..l

26,27

..ll

..4 5 ..ll

..3 4

..3

4 ..2 4 ..4 6

...

..19 ..4 3 ..4 4 ..3 7 ..2 3

...2 9

6 9

.lO

01972

McQuay

Division,

“McQUAY”

Nominal Capacity (Tons)

McQuay -

and “SEASONPAK”

Perfex Inc.

WHC _ 228A _ A t

are registered

NOMENCLATURE

trademarks of

- 6 k

- c k

- D t

Page 2

McQuay Division, Minneapolis, Minnesota.

R.H. CONDENSER, R H. EVAPORATOR

R.H. CONDENSER, L.H. EVAPORATOR L.H. CONDENSER, R.H. EVAPORATOR

L.H. CONDENSER, L.H. EVAPORATOR

INTRODUCTION

McQuay WHC Seasonpak centrifugal water chillers are completely

independent,

water.

The WHC Seasonpak centrifugal chillers are factory

assembled as a complete packaged unit, piped, wired,

automatic refrigeration systems, designed to chill

evacuated, charged with refrigerant and oil, and performance tested, ready for installation. shell and water thru-tube condenser:

Each unit consists of: a flooded refrigerant

a single stage gear driven centrifugal compressor with a liquid cooled hermetic motor, and an independent oil pump with reservoir system.

Also included are manual liquid line shut-off valves, liquid line trimming valve,

liquid line orifice and discharge line check

valve.

The 115 volt control center supplies power to the oil pump, oil

heaters,

automatic operation of the centrifugal chiller.

and all safety and operating controls for complete

Terminals are

provided for all necessary field interlock wiring between

control panel and unit starter, condenser pump relay, chiller

pump starter,

flow switch and oil cooler solenoid.

PRE-INSTALLATION

GENERAL

installation by qualified personnel only.

Equipment such as this is intended for

As a condition

of the warranty,the equipment start up must be performed under the supervison of a McQuay Service Representative. Failure to do so voids the warranty.

INSPECTION

II.

Upon receipt of equipment all items should

be carefully checked against the Bill of Lading to be sure all crates and cartons have been received.

All units should be carefully inspected for damage when received. Shipping damage may cause loss of refrigerant charge and

contamination of system.

If any damage is found it should be reported to the carrier immediately and a claim filed for damage.

McQuay,

will not be responsible for

any damage incurred in shipment.

LOCATION

This unit is designed for indoor application and must be

located in an area where the surrounding ambient

temperature is 40 F. or above.

A good rule of thumb is to place units where ambients are at least 5 degrees above the leaving water temperature.

Page 3

LOCATION

Because of the electric control devices, the units should

not be exposed to the weather.

(CONTINUED)

A plastic cover over the control box is supplied as temporary protection during transit.

An adequately strong foundation or base must be provided

for mounting the concentrated load of the unit. If

necessary,

additional structural members should be provided

to transfer the weight of the unit to the nearest beams.

Surfaces must be reasonably level.

Adequate free area must be provided around the installed

unit for connections and service.

Allow 14 feet for tube

removal and at least 3 feet around the remainder of the

unit for servicing compressor, oil pump, and controls.

MOVING AND MOUNTING UNIT

MOVING THE UNIT

The McQuay Seasonpak centrifugal chiller is mounted on heavy wooden skids to protect the unit from accidental damage and to permit easy handling and moving. Fig.

1 for physical and mounting information.

See

It is recommended that all moving and handling be

performed with the skids under the unit and that the

skids not be removed until the unit is in the final location.

When moving the unit, used under the skids.

dollies or simple rollers can be

In moving always apply pressure to the base on skids only and not to the piping or shells.

A long bar helps move the unit easily.

Always avoid dropping the unit.

When rigging the unit attach slings thru holes provided in the base and always use spreader bars to protect the control panel,

piping and insulation from

damage.

Do not attach slings to piping or equipment.

in the upright horizontal position at all times.

Move unit

Let unit down gently when lowering from the trucks or rollers.

Page 4

II.

HANDLING

Every model WHC Seasonpak centrifugal chiller is

supplied with a full refrigerant charge.

shipment, and is isolated by the manual condenser liquid line valves and discharge line check valve.

Should the unit be damaged allowing the refrigerant

to escape, equipment area since the refrigerant will displace the air. Care should be taken to avoid rough handling or shock due to dropping the unit.

UNIT FROM ANYTHING OTHER THAN THE BASE.

the charge is contained in the condenser

there may be danger of suffocation in the

Avoid exposing an open flame to refrigerant.

NEVER LIFT,

For

PUSH OR PULL

III.

MOUNTING THE UNIT

The negligible vibration normally encountered with

the Seasonpak centrifugal chiller makes this unit particularily

installations where the to the floor if desired. should be

building structure,

into the structure.

Mount the unit on the rubber

for use under each corner of

level installations or areas transmission is an important rubber-in-shear or spring-type isolators are recommended for maximum vibration isolation from the

building structure.

level unit.

desirable for basement or ground floor

unit

can be bolted directly

The floor construction

such

that the unit will not affect the

or transmit noise and vibration

isolation pads provided the base. in which vibration consideration, optional

Use steel shims if necessary to

WATER PIPING

On a.11 upper

GENERAL CHILLER AND CONDENSER PIPING (See Fig. 2)

When installing water piping follow established practices

and comply with local building and safety codes.

Shut-off valves should be provided at the unit so that

normal servicing of the unit can be accomplished without draining the entire system.

Page 6

WATER PIPING (CONTINUED) GENERAL

All piping should be installed and supported to

prevent the unit connections from bearing any strain

or weight of the system piping.

Vibration eliminators in all water piping connected to

the unit are recommended to avoid straining the piping and transmitting pump noise building structure.

It is recommended that temperature and pressure

indicators be installed within 3 feet of the inlet and outlet of the shells to aid in the normal checking and servicing of the unit.

A cleanable-type wire mesh strainer is recommended at

the condenser pump suction and must be provided at the evaporator pump suction to protect the pump and

shell from foreign matter.

foreign matter is allowed to block evaporator tubes.

and vibration to the

Freeze up can result if

Design the water piping so that it has a minimum

number of changes in elevation.

Include manual or

automatic vent valves at the high points of the water

piping,

circuit.

that air can be vented from the water

System pressures can be maintained by using an expansion tank or a combination pressure relief and reducing valve.

A preliminary leak check of the water piping should be

made before filling the system.

The water connections are of the grooved Victaulic

type for use with Victaulic couplings.

Matched fittings

must be field provided for the inlet and outlet

connections.

The water inlet is the bottom connection and the water outlet the top connection on both evaporator and condenser for all 2 and 3 pass units.

See Table I for chiller and condenser connection sizes.

If the shells must be drained for winter shut-down it

is recommended that an anti-freeze solution be circulated

and drained for positive freeze protection.

All supply and return water boxes for the evaporator

and condenser are provided with two pipe plugs which can be removed for venting and draining the shells.

Page 8

II.

CHILLED WATER PIPING

All chilled water piping should be insulated to

prevent condensation on the lines. If insulation is not of the self-contained vapor barrier type, it

should be covered with a vapor seal. not be insulated until completely leak tested. Vent and drain connections must extend beyond proposed

insulation thickness for accessability.

Piping should

The system cycling thermostat, TC(W) and electronic

vane control EVC are mounted inside the control

console with the sensors mounted in the evaporator

leaving water connection. The low water temp safety TS(LW),

sheet. charged capillary tubing when working around the unit.

before running the unit to be sure that it is firmly

anchored and not rubbing on the frame or any other component.

The evaporator water boxes can be interchanged end

for end so that the water connections either end of the unit. sensors discussed above must be moved to sense the

leaving water temperature from the unit.

gaskets must be used if a change is made. must be trimmed to conform to block-off baffle arrangements in the water boxes which vary with the number of passes in the shell.

sensing bulb is located in the chiller tube Care should be taken not to kink or break the

It is also advisable to check the cap tube

can be

If this is done the 3

New head

made at

Gaskets

III.

CONDENSER

Water cooled condensers may be piped for well water applications, cooling tower.

include a small amount of waste circulating water

and adequate water treatment provided to prevent build-up of contaminants and scale in condenser tubes and tower basin.

The condenser water boxes can be interchanged end

for end so that the water connections can be made at

either end of the unit. trimmed and used if a change is made.

The minimum entering water temperature to the condenser is 65 F. cooling tower or condenser bypass or by thermostatic control of the cooling tower fans,

WATER PIPING

or for use in conjunction with a

Cooling tower applications should

New head gaskets must be

This can be accomplished by a

Page 9

CONDENSER WATER PIPING

A condenser flow switch is not required and cannot

be wired directly into the interlock circuit. If used,

a normally closed timer must be used to bypass

the condenser flow switch on start up.

(CONTINUED)

IV.

OIL COOLER WATER PIPING

A minimum of 8 GPM of water at 85 F. or lower

temperature must be provided to the oil cooler to

maintain the oil temperature leaving the cooler at

NPT connection is

a maximum of

110 F.

the inlet and the top

If condensing water is used it is imperative that the

The bottom

NPT connection is the outlet.

1""

water temperature be kept within design limits to keep

oil temperature supply below 110 F.

There is also a potential problem due to fouling which reduces effectiveness.

This problem must be recognized and

frequent tube cleaning may be required.

When chilled water is used as the source of water for

the oil cooler it should be piped across the chiller pump directly to assure full pump pressure across the oil cooler.

See Figure below.

DRAIN

VALVE

Preferred Oil Cooler Piping

t’

WITHLN

3FT OF COOLER

CHILLED WATER

PUMP

EVAPORATOR

Page

If it is necessary to connect the oil cooler in

parallel with either shell, it is essential that

the

pressure

drop in the line be kept down to assure

adequate flow to the oil cooler. The oil cooler

water pressure drop is 3.5 feet of water at 8 GPM.

City water can also be used as the source of supply.

A flow balance valve should be provided and the

drain line should be trapped to prevent the oil cooler from draining on the off cycle.

In a.11 cases a strainer with a maximum

l/4"

should be provided at the oil cooler inlet and a normally closed

must be

provided and wired as shown on the unit

115V.

solenoid valve (water duty)

wiring diagram.

REFRIGERANT VENT PIPING

Both the evaporator and the condenser shells have

pressure relief valves to vent out refrigerant gas

if an unsafe pressure should build up in the shell. It is recommended that these valves be vented to the outside to meet local codes.

piping procedure follow ASA

B9-Sec.

For proper vent

12, ASME and

local codes.

ELECTRICAL

mesh

POWER

WIRING

The WHC Seasonpak centrifugal chiller is designed to be used in conjunction with a separately supplied starter of the across-the-line,star-delta or auto-transformer type. The starter and overloads are specifically selected for application with a specific size Seasonpak centrifugal chiller.

All field wiring must comply with local, state and

Standard NEMA motor starters are not acceptable.

National Electrical Codes.

All fuses and wiring between disconnect, starter, and

motor must be in accordance with the National Electrical

Code.

The compressor motor is supplied with 6 terminals for

use with across the line, star-delta, or auto-transformer

starters.

When across-the-line or auto-transformer

starters are used terminals l-6, 2-4 and 3-5 must be

jumpered together with terminal straps.

Page 11

ELECTRICAL POWER WIRING (CONTINUED)

CARE must be used in wiring leads to compressor motor

terminals to assure that proper phase relationship is carried through starter to motor. CONNECTIONS TO THE COMPRESSOR ARE NOT TO BE MADE UNTIL POWER WIRING HAS BEEN CHECKED AND APPROVED AY AN

AUTHORIZED McQUAY FIELD SERVICE REPRESENTATIVE.

CAUTION: DO NOT TURN MOTOR TERMINAL STUDS WHEN MAKING POWER CONNECTIONS.

THIS COULD LOOSEN STUD NUTS AND

CAUSE REFRIGERANT LEAKAGE.

The power wiring to the compressor must be in the

proper phase sequence

for correct motor rotation.

With phase sequence of l-2-3 and

Tl-T6,

L2 connected to T2-T4 and L3 connected to T3-T5

the motor will rotate in the proper direction (clockwise when checking in motor sight glass).

and L3 lines at compressor motor junction box.

L2,

EXTENSIVE DAMAGE CAN RESULT IF MACHINE IS ALLOWED TO

RUN IN WRONG DIRECTION.

McQUAY IS NOT RESPONSIBLE FOR MACHINE DAMAGE CAUSED BY REVERSAL OF POWER PHASE BY POWER COMPANIES,

ELECTRICIANS OR OTHERS.

NOTE:

connected to

FINAL

Label

Ll,

II.

CONTROL WIRING

A separate source of 115 volt,

cycle power is required

for the Seasonpak centrifugal chiller control circuit. This circuit is to be fused at 15 amps to protect the control circuit from overload.

A.B.IMPORTANT

THE DISCONNECT TO THIS CIRCUIT MUST REMAIN

ON AT ALL TIMES TO MAINTAIN PROPER OIL TEMPERATURE IN THE SEASONPAK CENTRIFUGAL CHILLER TO PREVENT

REFRIGERANT FROM ACCUMULATING IN THE OIL.

ATTACH A LABEL WITH THE ABOVE NOTE TO THE CONTROL

CIRCUIT DISCONNECT SWITCH.

The source of power for the control circuit can be transformer, if provided, in the unit starter.

The transformer must be rated at 3 KVA with an inrush rating of 18 KVA.

If the transformer is used as a

source of power the unit disconnect should also be

marked with the label shown above in Paragraph A.

Page 12

III.

AUXILIARY WIRING

In addition to the power wiring supplied to the unit control center,

additional interlock wiring is required and is to be wired directly to terminals provided in the control center. size for the amp capacity of the circuit.

Wire Gauge #14 THW is of sufficient

Consult the

auxiliary interlock wiring diagram (Diagram 1) for

detailed wiring information.

Wire the two sets of normally closed contacts (in

unit starter) to terminals 26, 27, and 33, 34 in the control center.

Add wires from the current transformer provided in, the unit starter to terminals 37, 38 in the control center.

Provide a chiller pump interlock to prevent the compressor from starting until chiller water flow has

been established.

A set of normally open contacts on the chiller pump starter is required in conjunction with a flow switch to be wired to terminals 29, 40, and 30.

Provide a condenser pump relay with 2 sets of normally open contacts (115 v. coil max. 100 VA rating),

to start the condenser water pump at the time the compressor is ready to start and cycle the condenser pump with the compressor. control center terminals 24,

28 with a set of normally

Wire coil to

open contacts wired to terminals 24, 25 and the

second set of normally open contacts to start the

condenser water pump.

Wire in the leads from the

oil cooler water solenoid

(115 V. coil) to terminals 8 and 6 in the control

center.

Add interlock wiring between the control center

terminals 25 and 28 and the m&r starter relay in the unit starter.

Terminals 35 and 36 in the control center can be

wired into a customer supplied and powered alarm

circuit if desired.

Terminal 39 is a ground terminal for the control panel and should be wired to a suitable ground if

local codes permit.

Page 13

The necessary operational and safety controls for the McQuay Seasonpak centrifugal chiller are mounted in the control center or incorporated in the system.

between the starter, pumps, and unit:

With the interlock wiring

the control circuit is complete

and the system will operate automatically.

A description of the controls,

control function and set point is

shown in Table II.

A schematic wiring diagram incorporating wire numbers is shown on

P 26

27. The numbers on the left of the

diagram designate

the

line numbers as an aid in following the sequence of operation.

With 115 V. power to the control circuit, the system switch

"Off"

and the unit calling for cooling the following sequence

of operation applies.

I SEQUENCE OF OPERATION (Note: A simplified Sequence Appears

in Catalog 920)

Power is fed thru the normally closed contacts of TD(P) and

energizes the oil sump heater and compressor heater (L. 65).

Power is also fed to transformer,

Tl,

(L.85) energizing the 24V. circuit controlling the vanes and energizing the D.C. motor relay (L. 82) closing R (T) contacts

Providing all safeties

PS(L0)

and R(T) are made,

PS(HR), PS(LR), TS(HR), TS(HO), TS(LW);

reset switches 2-8 can be pushed energizing

relays R4-R10 and de-energizing lights

l-2(L.52).

LTl-LT7.

With the l-3 contacts of R4-R9 closed,

R3 is energized closing

its contacts 4-6 in the compressor starter circuit (L.25).

If 40 minutes have elapsed since the machine has last started,

Rll

will be de-energized and Rll contacts 1-2 closed (L-21).

By switching Sl to the "on" position, power is now fed thru TD(L) normally closed-timed open contacts if all interlocks are closed and above conditions have been met.

The

TD(P)

closed

motor,

providing oil pump overload, OL is closed (L.13).

All Ml contacts of the oil pump starter close, starting the

clutch coil is energized closing TD(P) normally

timed open contacts which energizes Ml contactor and

oil pump and energizing the field wired oil cooler solenoid.

Closed vane indicator control, PC(V), will close at 30 PSIG oil pressure differential (only if vanes are closed).

TD(P)

Page 15

+ 36 hidden pages

McQuay WHC Installation Manual

TABLE OF CONTENTS

PRE-INSTALLATION

LOCATION

WATER PIPING

ELECTRICAL