TABLE 1. CONTROL COMPONENT SUMMARY - STANDARD APPLICATIONS
CONTROL SYMBOL SETTING
RESET
LOCATION
SIGNAL
(Note 1) LIGHT
FUNCTION
Alarm Relay
Chiller Pump,
Waterflow Interlocks
CHWI
None Auto/Man
None Auto/Man
Relay
Section
Field
Supplied
None
Ext.
Fail
Actuates circuit for remote alarm (where an AL relay is used, R9
signals opening of a water circuit interlock.
Prevents chiller operation until chilled water pump is energized and
flow is established.
Cold Oil Temperature
Switch
COT 105°F Auto/Man Switch Oil Stops compressor if oil temperature entering compressor drops below
Section Temp. settinq. R114 Templifiers only.
Condenser Pump,
Waterflow Interlocks
CWI
None Auto/Man Field
Supplied
Ext.
Fail
Prevents chiller operation until condenser water pump is energized
and flow is established.
Guardistor Relay G R None Auto/Man Relay
Section
Motor Stops compressor motor when winding temperature exceeds limit.
Temp.
Hot Gas Override
Solenoid
HGO None None Hot Gas
Piping
None Opens hot gas bypass at starling of 2nd compressor oil pump to
reduce starting head. Dual compressor units only.
Hot Gas Solenoid HGS None None Hot Gas
Piping
None Opens hot gas bypass from discharge to evaporator, providing false
evaporator load. Helps prevent surge conditions.
Hot Gas Thermostat HGT Field Set None Condenser
Frame
None Energizes hot gas solenoid on drop in water temperature entering
evaporator (senses entering condenser water in Templifier).
High Oil Temperature H O T 140°F Manual Switch Oil Stops compressor if oil temperature entering compressor exceeds set-
Switch Temp.
(R12)
Section ing (reset auto/man with RI 14 Templifiers).
High Pressure Switch HP See Manual Switch Disch.
Stops compressor when discharge pressure exceeds setting. Set
Function
Section Press
10-12 psig above design saturated condensing pressure (not to ex-
ceed 90% condenser nameplate maximum working pressure).
High Suction Temp.
Switch
High Discharge
Temp. Switch
HST
HT
Auto/Man Temp. Surgegard Stops compressor when suction temperature exceeds setting prevents
Section compressor surge (CEO50 compressor only).
225°F Manual Switch High Stops compressor when discharge gas temperature exceeds setting.
Section Temp.
Interval On Timer
Low Casting Temp.
Thermostat
IOT
LCT
Field Set None Lead/Lag None Actuates circuit for specific time and returns to normal position after
Box
time delay.
Auto Temp.
O i l
Assures minimum compressor casting temperature at startup.
Section Temp. (CE126 compressor only).
Liquid Injection
Solenoid
LIS
None None Refrig.
Piping
None Opens liquid injection valve after compressor starts-standard on
CE126. (Optional for CE063, 079, 087, 100) (Not used on R114 units)
Load Meter
Low Oil Temp.
Thermostat
LM
LOT
None
130°F
None
Auto
Panel
Temp.
Section
None Displays percent of full load amps when compressor runs.
Oil Prevents compressor start with cold oil. Set as high as conditions
Temp. allow. Protects compressor bearings from refrigerant diluted oil.
Low Pressure
Switch
Pump Down Control
Switch
Low Pressure
Override Switch
Load Recycle
Thermostat
Liquid Line Solenoid
Valve
Oil Pump Contactor
LP See Manual
Switch
Low Stops compressor when suction pressure drops below setting. Set
Function Section Press. 5 psig below shop order suction pressure.
LPC
2-5 psig Auto Side of None Stops compressor when suction pressure setting is reached-part of
above LP Panel
one-time pump down control feature-SE units only.
LPO
2 psig Auto
Switch
None Overrides control module, unloads compressor when suction pressure
above LP Section approaches setting of LP cutout-prevents nuisance trip.
LRT Field Set None Temp. Load Starts/stops compressor in response to load changes-stops
Section Recycle compressor 3°F below control point. (See PF manual for LRT2
setting.)
LS
None None Field None Opens on call for cooling or heating. Closes when system thermostat
Supplied or controller is satisfied.
IM
None None Relay None Starts oil pump when energized.
Section
Motor Control
Relay
Motor Cooling
Solenoid Valve
Oil Cooler
Solenoid
Oil Pressure
Diff. Switch
Oil Pump
Overload
Oil Pump Safety
Timer
MCR
MCS
o c s
OD
OL
OPT
None None Starter Comp. Energizes compressor motor starter when unit control circuit is
Run energized.
None None Refrig. None Opens to feed liquid refrigerant for motor cooling during compressor.
Piping operation.
None None Chiller None Opens valve to permit coolant flow during oil pump operation.
Piping
50 psig Auto/Man Lube Oil Stops compressor when difference between oil and suction pressure
opens Box Press. drops to setting. Closes at 60 psig to permit compressor start.
Non-
Auto/Man Lube O i l
Stops oil pump and compressor if oil pump motor overloads electric
Adjust. Box Press.
circuit.
60 sec. Auto/Man Relay Oil Stops pump by interrupting safety circuit if vane closed switch fails to
Section Press. close within 60 seconds afler oil pump starts.
IM 307 / Page
