McQuay TEH050 Installation Manual

APPLICATION

The operation and maintenance procedures presented in this manual apply to the models

TEH050-126.

Reference to the installation manuals for these units should be made for details pertaining to receiving and handling, installation, piping and wiring, and preparation for initial start up.

All McQuay Centrifugal Templifiers are factory tested prior to shipment and must be initially started by a factory trained McQuay Service technician. Failure to follow this start-up procedure may affect the equipment warranty.

The standard warranty on this equipment covers parts which prove defective in material or workmanship. Specific

OPERATION

OPERATOR RESPONSIBILITIES

It is important that the operator become familiar with the equipment and the system before attempting to operate the Templifier.

In addition to reading this manual the operator should study all the control diagrams furnished with the unit so that he understands the starting, operating and shut-down sequences as well as the safety shut-down modes.

When the McQuay Service technician performs the initial start-up of the Templifier he will be available to answer any questions and to instruct in proper operating procedures.

It is recommended that the operator maintain an operating log for each individual unit. In addition, a seoarate maintenance log should be kept of the periodic maintenance

details of this warranty can be found in the warranty state-

ment furnished with the equipment.

In the application of Templifiers, each unit is designed for specific heat recovery conditions to achieve the highest possible performance. In order to maintain the design performance levels, the equipment must be operated and maintained according to the procedures in this manual. The operating and maintenance procedures in this manual will apply equally to both TEH and THH models unless specifically noted. For simplicity only the TEH designation will be used.

and servicing activities.

This McQuay centrifugal Templifier represents a substan-

tial investment and deserves the attention and care normally given to keep this equipment in good working order. If the operator should encounter abnormal or unusual operating conditions, it is recommended that a McQuay Service technician be consulted.

McQuay conducts training for centrifugal operators at its factory Training Center several times a year. These sessions are structured to provide basic classroom instruction and include hands-on operating and troubleshooting exercises. For further information, contact vour

McQuav reoresentative.

MODEL CODE

T EH

~~~;;y~

NOMENCLATURE

Each centrifugal Templifier is assigned a set of identifying numbers which are used to describe the unit features and to identify each individual unit. These four-number groups are stamped on each unit nameplate. A typical nameplate is shown in Figure 1.

The first number is the unit model number, this identifies the unit. The second is the unit style number, followed by a serial number and a shop order number (S.O.). The unit

nameplate is also stamped with the type and operating charge

of refrigerant.

All inquiries pertaining to operating and servicing of this

unit should include all identification numbers.

Each of the individual components also have nameplates to provide certain necessary information to the installer and the operator.

The compressor nameplate identifies the compressor

model, style and serial numbers and includes the electrical

characteristics of the compressor motor. The CEO50 com-

pressor nameplate also shows the oil pump electrical

characteristics.

The condenser and evaporator vessels have nameplates stamped with the maximum working pressure of the vessel. It should be noted that the vessel relief valve maximum settings coincide with the maximum refrigerant side vessel working pressure.

063K AR

FIGURE

1. Unit Nameplate.

MODEL STYLE SERIAL S.O. NO.

~~~~~~~

~_.__

FACTORY CHARGED

LSS. REFRIGERANT-

LEAK TEST PRESSURE 100 PSIG.

MOTOR - COMPRESSOR CONTROLLER

AND OVERLOAD PROTECTION FIELD

SUPPLIED. SEE SPEC.

PE-D4

NOMENCLATURE CHANGE: The model nomenclature TPE and TPH has been changed to TEH and THH respectively. TPE and TPH are synonymous with TEH and THH respectively.

IM 315

Page 3

OPERATING

The operation of a Templiifer is similar in some ways to that conventional chiller, Heat is picked up by the evaporator and transfered to the condenser via the conventional refrigeration cycle. Source fluid temperatures entering the evaporator are usually higher than chilled water systems, consequently, the water leaving the condenser is at higher temperature and thereby more useful for heating purposes.

Although there are no two Templifier control schemes ex-

actly alike, there are four basic control arrangements, and

most applications are adapted from one of them. They are:

1. Process or Service Water Heating

2. Environmental Heating

3. Boiler Feedwater Heating

4. Combination Heating/Cooling When in automatic control mode, the compressor is nor-

mally cycled on and off in responce to a Load Recycling Thermostat (LRT); during operation the compressor capacity is controlled by as control module located in the control center. The sensing point for these controls varies with the application. Schematics of the four arrangements are shown in

Figures 2

During all phases of operation, the critical functions of the

Templifier are under constant surveillance by the safety controls Abnormal conditions will cause the chiller to be shut

down and usually will require some corrective action to prevent recurrence. A set of panel lights on the control panel will indicate the cause of shutdown. For the protection of the equipment, the operator should determine the exact cause of shutdown and correct the situation prior to operating the

unit again.

PROCESS/SERVICE WATER HEATING

This system is applied to process heat recovery and service water installations when the requirement is to maintain a constant hot water temperature. The sensor for capacity regulation is located in the condenser leaving water, and the com-

pressor on/off control (LRT) responds to condenser entering

temperature. (See Figure 2).

FIGURE 2.

SOURCE

FIGURE 3.

SOURCE

WATER

EVAPORATOR

BOILER FEEDWATER HEATING

This system utilizes a waste heat source to preheat makeup water for heating

or process

boilers. Capacity control is usually set at maximum design temperature and the Templifier will normally operate at or near full load to take full advantage of the available waste heat. The load recycling thermostat functions more like a safety control since the makeup water should not rise to cutout temperature. (See Figure 4).

FIGURE 4.

HEAT EXCHANGER

WATER

CONDENSER

TO BOILER

PREHEATER

COMBINATION HEATING/COOLING

The combination system operates as a chiller for comfort cooling during summer periods and as a heating unit in winter heating periods. During heating mode, a waste heat source is channeled through the evaporator. Compressor on/off control is from thermostats (LRT) in the evaporator inlet for cooling and in the condenser inlet for heating. This system is sometimes fitted with a separate cooling tower condenser for summer heat rejection. (See Figure 5

FIGURE 5.

1~i-i

SOURCE OR

CHW RETURN

EVAPORATOR

ENVIRONMENT HEATING

For space heating applications, the compressor capacities may be controlled to maintain a constant return water temperature. This system effectively varies (or resets) the temperature of the heating water with system load changes. Compressor starting is controlled from condenser entering water temperature, whereas compressor shutdown is signaled from condenser leaving temperature. (See Figure 3).

For the proper operation of the centrifugal Templifier, a

thorough understanding of the control is essential.

The controls are housed for the most part in the Control Center and in the Lube Box, both of which are mounted on the Templifier assembly.

Page 4

I IM 315

RETURN

CONTROL SYSTEMS

A complete summary of the control components presented in Table 1 identifies each control, its location and setting, along with a brief description of its purpose in the control scheme. Most of these controls are standard on all units while a few may be special purpose or optional devices. Using this

-4

------7

OPTIONAL

TOWER

CONDENSER

SUPPLY

I--1

--)

chart in conjunction with the control diagram shipped with the unit will aid in understanding the various control modes.

For the purpose of describing the controls, they have been divided into two categories Operating Controls and Protective Controls and in each group, certain of the important controls will be reviewed in some detail. There are a dozen or so relays in the control center which respond to another controlling device to open or close circuits. These relays can be identified by the operator from the control diagram.

OPERATING CONTROLS The operating control group consists of devices which serve specific functions in starting, operating and shutting down the centrifugal compressor during normal operating conditions. For this description it is assumed that the system conditions monitored by the safety and protective controls are

normal and that those controls are positioned for running.

The ON-OFF switch on the control panel provides a means of manual control to energize or de-energize the operating circuit. When this switch is turned on, its self-contained light will energize and the control circuit is ready for automatic operation of the compressor.

The Load Recycling Thermostat (LRT) sensing water temperature will cycle the compressor on the line when the water temperature reaches the ON control point, and will shut the compressor down when the water temperature drops to the OFF setpoint. The setting procedure is detailed in the adjustment section of this manual.

To assure that the compressor will not be started too frequently, the Time Delay Relay (TDR) will prohibit a restart within 20 minutes of the last shutdown. This timing is for the

protection of the compressor motor and is not adjustable. It is classified as an operating control because it functions as a part of the starting sequence.

On R12 units, once the TDR contacts close, the oil pump

is started and the Prelube Timer (PLT) is energized to assure

oil pumping and bearing lubrication for a fixed time prior to

compressor start. On

after the vane closed switch (VC) closes. At the same time, the oil heaters which have been energized during the compressor-off period are now shut off.

Simultaneous with starting the oil pump, the Oil Cooler Solenoid (OCS) in R12 units is energized, permitting coolant to flow through the oil cooler to remove the heat generated by the compressor bearings once the compressor starts. When RI 14 is used the OCS is energized simultaneously with oil pump starting providing the vane closed switch (VC) is closed.

For R12 units at the end of the prelube period the control circuit is completed up to the Vane Closed switch (VC) which monitors the position of the compressor capacity control vanes. This switch permits compressor starting only when

the vanes are in the fully closed position. On

prelube period starts as soon as the vane closed switch closes.

To complete the control circuit for compressor starting, the pump interlocks and water flow interlocks for the condenser water and source water must be closed.

Once the compressor is started, the Control Module functions to load and unload the compressor in response to changes in the water temperature. The Control Module will be discussed in greater detail in a later section.

As the system toad reduces and the Control Module unloads the compressor, the compressor will continue to run until the LRT shuts off the machine when the water

temperature reaches the OFF set point.

The control panel has two lights which indicate the status of control. The COMP. RUN light shows that the compressor is running under normal control and the LOAD RECYCLE light indicates the compressor has been taken off line by a normal operating control and is waiting for a restart signal.

R114

units the PLT timing starts only

R114

units the

PROTECTIVE CONTROLS Each McQuay centrifugal Templifier is equipped with a complement of safety controls to prevent the compressor from starting under adverse conditions or to take the machine offline when abnormal or unsafe conditions develop during

operation.

In addition, there are a number of relay type devices which operate to assure that the starting, operating and stopping functions are carried out in proper sequence for the protection of the equipment. These relays can be identified on the

unit control diagram as

The control panel is equipped with several indicator lights to provide the operator with a quick status condition when the compressor is shut down. With the reference to Figure 6 it will be noted that there are eight safety signal lights to describe some condition which has caused the compressor to be shut down. In a fault condition only one light can be

energized at one time. FIGURE 6. Control Panel Lights

MOTOR

TEMP

LOAD

RECYCLE

Most of these indicator lights are operated when some abnormal condition exists with the Templifier unit. Conditions such as low suction pressure, high discharge pressure, low oil pressure or temperature, high motor winding temperature and surge condition may cause some damage to the equipment if allowed to continue uncorrected.

The troubleshooting guide on page 19 gives the operator a comprehensive list of fault conditions and the probable causes. This guide should be consulted whenever the com-

pressor is shutdown by a protective control.

Each unit is equipped with an “External Failure” light on the control panel. When energized, this signal indicates the compressor cannot run due to a control problem external to the control panel. Faults in the condenser water/source water circuits or in the compressor starter could trigger such an external failure signal. This feature helps the operator locate control system problems. Causes and corrective actions are further described in the troubleshooting guide.

The two most severe failures which can occur in a hermetic

centrifugal compressor are surge conditions and motor failure. McQuay has developed highly reliable protective systems to guard against both of these failures. An understan-

ding of each will be helpful to the operator in analyzing the

unit performance. Both Guardistor and Surgegard are safe-

ty protective systems developed by McQuay.

Guardistor Motor Protection-Positive protection against

motor overheating is provided by the Guardistor system. The

heart of the Guardistor protective circuit are the thermistors

embedded in the motor windings to sense motor winding temperature. When the motor temperatures are normal, the

thermistors have low resistance which remains nearly cons-

tant up to a predetermined critical temperature. At this

temperature, a sharp increase in resistance causes the

Rl,

R2,. etc.

KS,

0 SURGEGARD-”

UNIT

Guar-

315 I Page 5

distor relay to drop out and cause the control circuit to stop the compressor. Such failure causes a lockout mode requiring manual reset.

Surgegard-McQuay

uses Surgegard to sense the occurrence of surge condition and to stop the compressor before the machine is damaged. The Surgegard relay will also prevent the compressor from restarting until the cause of the malfunction has been corrected. Possible causes for surge, or rotating stall condition, may be dirty condenser tubes or cooling tower or pump malfunction, which acts to elevate the system’s head. The Surgegard relay is the safety control which shuts shuts off the compressor under abnormal conditions in the

TEH063,

079, 087, 100 and 126 Templifiers.

In the TEH050 the high temperature thermostat provides this

safety function. These controls are factory set and require

no field adjustment.

SAFETY CONTROL RESET

Certain safety controls in the Templifier control panel will lock out automatically when operating conditions exceed trip set-

tings. As an example, if the refrigerant discharge pressure leaving the compressor exceeds the trip setting of the high pressure cutout switch, the compressor will be taken off-line and cannot be restarted until the pressure has returned to

normal and the high pressure cutout has been manually reset.

In the control center several other safety functions also lock out under abnormal operating conditions. These controls include the low pressure cutout, high discharge temperature thermostat, high oil temperature switch, low oil pressure, high suction temperature switch

(TEH/THHO63-126)

and external system failure.

(TEHITHH050 only), Surgegard

Each of these fault signals can be identified by the control

panel lights and all can be reset with the single RESET but-

ton on the front of the control panel when the fault has been

corrected.

In the event of electrical system power interruption, the

Templifier units

will lock

out and will not restart automatical-

ly. The EXT. FAIL light will go on when power is restored and

the RESET button must be manually reset to restore

automatic operation.

CONTROL COMPONENT SUMMARY

CONTROL

Alarm Relay

Chiller Pump, Waterflow Interlocks Supplied

Cold Oil Temperature Switch Section Temp.

Condenser Pump, Waterflow Interlocks Supplied

Flow Switch Time Delay

Guardistor Relay

Hot Gas Override Solenoid

Hot Gas Solenoid

Hot Gas Thermostat

High Oil Temperature

Switch Temo. lR12) Section Temo. ina

High Pressure Switch

High Suction Temp.

Switch

High Discharge

Temp. Switch

Interval On Timer

Low Casting Temp.

Thermostat

Liquid Injection Solenoid

Load Meter Low Oil Temp.

Thermostat

Low Pressure Switch

Pumpdown Switch

Law Pressure Override Switch

Control

SYMBOL SETTING

CHWI None

COT

CWI

FSTD None

GR None

HGO None None

HGS None None

HGT

HOT

HP See Manual Switch

HST

IOT

LCT

LIS

LOT

LPC

LPO

None

105°F Auto/Man

None

Field Set

140°F

Function Section Press.

150°F Auto/Man

225°F

Field Set

110°F

None None

None None Panel

130°F Auto

See

Function

2-5 psig Auto Side of

above LP

2 psig Auto

above LP

RESET

(Note 1)

Auto/Man

Auto

Auto/Man

None

Manual Switch

Manual Switch High

Ngne

Auto Temp.

Manual Switch

LOCATION

Relay

Section

Field Ext.

Switch

Field Ext.

Relay

Section

Relay

Section

Hot Gas

Piping

Hot Gas

Piping

Condenser

Frame

Temp.

Section

Section Temp.

Lead/Lag

Box

Section Temp.

Refrig.

Pipinq

Temp.

Section

Panel one-time pumpdown

Switch None

Section

Surgegard Stops compressor when suction temperature exceeds setting prevents

SIGNAL

LIGHT

None

Fail

Oil

Fail Ext.

Fail

Motor

Temp.

None

Oil

Disch.

None

Oil

None

Oil

Temp.

LOW

Press.

None

STANDARD APPLICATIONS

Actuates circuit for remote alarm.

Prevents chiller operation flow is established.

Stops compressor if oil temperature entering compressor drops below setting.

Prevents chiller operation until condenser water pump is energized

and flow is established.

Delays water flow bypass for three seconds to prevent false shutdown

Stops compressor motor when winding temperature exceeds limit.

Opens hot gas bypass at starting of 2nd compressor oil pump to

reduce starting head. Dual compressor units only.

Opens hot gas bypass from discharge to evaporator, providing false evaporator load. Helps prevent surge conditions.

Energizes hot gas solenoid on drop in water temperature entering

evaporator (senses entering condenser water in Templifier).

Stops compressor if oil temperature entering compressor exceeds

Stops compressor when discharge pressure exceeds setting. Set

lo--12

ceed 90% condenser nameolate maximum warkina oressure).

camoressor surae Stops compressor when discharge gas temperature exceeds setting.

Actuates circuit for time delay.

Assures minimum compressor casting temperature at startup. (CE126 compressor only).

Opens liquid injection valve after compressor starts-standard on CE126.

Displays percent of full load amps when compressor runs Prevents compressor start with cold oil. Set as high as conditions

allow. Protects compressor bearings from refrigerant diluted oil. Stops compressor when suction pressure drops below setting. Set

5 psig below shop order suction pressure. Stops compressor when suction pressure setting is reached-part of

Overrides control module, unloads compressor when suction pressure approaches setting of LP cutout-prevents nuisance trip.

FUNCTION

unttl

chilled water pump is energized and

R114

Templifiers only.

(reset auto/man with

psig above design saturated condensing pressure (not to ex-

(Optional for

R114

Temolifiers).

(CEO50 comoressor onlv).

specific

time and returns to normal position after

CEO63

079, 087, 100) (Not used on R114 units).

control feature-SEH units only.

set

Page 6 I IM 315

Continued. CONTROL COMPONENT SUMMARY - STANDARD APPLICATIONS

CONTROL

SYMBOL SETTING

RESET

(Note 1)

LOCATION

SIGNAL

LIGHT

FUNCTION

Load Recycle

Thermostat

Liquid Line Solenoid

Valve Oil Pump Contactor

Motor Control Relay

Motor Cooling Solenoid

Valve

Oil Cooler Solenoid

Oil Pressure Diff. Switch

011 Pump Overload

Oil Pump Safety Timer

Oil Pump Time Delay Switch

Pushbutton Switch

Prelube

Timer

Protective Signal Interlock

Phase Voltage Relay

Range Shift Resistor

Capacity Control Solenoid

Starts Counter Surgegard Relay

System Monitor Timer

Sump Oil Thermostat

Sequence Relay

Source Water

Thermostat Anti-Recycle Time

Delay Relay

Transition Resistor

Protector Pilot Expanasion

Valve Solenoid Vane Closed

Switch

Vane Delay

Contacts

Voltage Relay

NOTE

#l.

Auto-This control automatically resets itself.

Auto/Man-This control automatically resets itself but electrical lockout

NOTE X2. This table contains all standard and most optional control components used in McQuay centrifugals. All listed controls are not necessarily used on

all units. Controls for specific units can be identified by

Field Set

LRT

MCR

MCS None None

ocs

OPT

OTDPB60 sec.

PLT

PVR

RSR

SA None

SGR

SOT

SR None None Field

SWT

TDR

TRP

TXS

vc 40 psig

VR Non-

None None Field

None None Relay

None None

50 psig Auto/Man

opens

Non-

Adjust.

60 sec.

None

60 sec.

None

None None Lube

None

Non-

Adjust. 60 sec.

140°F

Field Set

20 Min.

None

Differential

None None

Adiust.

None Temp.

Auto/Man

None

Auto/Man

None Control None

None Lube

None

Auto/Man

Auto Control

Auto

None

Auto/Man

None

None Lube

Section

Supplied

Section

Starter

Refrig.

Piping

Chiller

Pioina

Lube

Relay

SectIon Press.

Relay

Section

Switch

Section

Relay

Section

Starter

Module

Panel

Relay

Section

Relay Ext.

Section

SuppIled

Temp.

Section

Relay

Section

Starter

Piping

Lube

Starter

Manual-This control requires manual reset which is done mechanically with RESET button.

Load

Recycle

None

Comp.

Run

None

Box

Box maintain set temperature.

Box

referrmg

Press.

Press. circuit

None

Ext. Fall

Ext. Fail

Module Part of

Red

Module

Green

None

Surgegard Works with thermistor to sense impeller cavity temperature. Protects

Fail

None

Load

Recycle

None

Ext.

None

Press.

None

to control diagram and/or the unit control center.

Starts/stops compressor in response to load changes-stops compressor 3°F below control point. (See TFH manual for setting.)

Opens on call for cooling or heating. Closes when system thermostat or controller is satisfied.

Starts oil pump when energized.

Energizes compressor motor starter when unit control circuit is energized.

Opens to feed operation.

Opens valve to permit coolant flow during oil pump operation

Oil

Stops compressor when difference between oil and suction pressure drops to setting. Closes at 60 psig to permit compressor start.

Oil

Stops oil pump and compressor if oil pump motor overloads electric

Stops pump by interrupting safety circuit if vane closed switch fails lo

Oil

close Keeps pump

Pushbutton switches reset the safety

on the control panel is pushed. Provides a pre-lubrication period for bearings prior to compressor

start. De-energizes system monitor

delta contactor Protects compressor against damage from single phase, phase

sal or undervoltaqe. Provides temperature range shift for control module on Templifier

units.

on control piston and closes vanes-UNLOAD. Part of

on control piston and opens vanes-LOAD. Counts number of compressor starts.

compressor from a surge (CEO63 thru 126). If compressor fails to start in 60 seconds after system monitor is

energized, system monitor terminates start effort. On units with refrigerant cooled oil cooler, controls oil sump heater lo

Relay controlled by system thermostat (or other control) to start unit

on call for cooling.

Stops compressor when water temperature entering evaporator is too low for practical heat recovery.

Prevents compressor from restarting for 20 minutes after previous shutdown.

Abort compressor starting sequence if starter fails to make transition from star lo delta within 1 second.

Fail

Opens when 2nd compressor starts, closes when 2nd compressor stops (TFH063 only).

Oil

Prevents compressor starting unless capacity control vanes are closed

(fullv

unloaded).

Auxiliary contacts in compressor starter prevent compressor loading

and liquid solenoid valves from opening (SEH units only) until compressor motor connected across the line.

Disconnects oil pump motor capacitor affer start (CEO50 only)

circutt

requires that RESET button be pushed to reset the circuit.

ltquid

refrigerant for motor cooling during compressor

withln

60 seconds after oil pump starts.

runnmg

for 60 seconds after compressor is stopped.

4-way solenoid

4-way

valve. When energized, applies full oil pressure

solenoid valve. When energized, applies full oil pressure

ctrcult

when the RESET button

timer

when compressor starter closes

LRTZ

rever-

315 I Page 7

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