Carrier GR-45 - 1.3 Refrigeration System Component Specifications; 1.4 Electrical Specifications - Motors; 1.5 Electrical Specifications - Sensors and Transducers; 1.6 Safety Devices

1-5
T--295
In the cooling m ode the compressor is energized while
the evaporator and condenser fans are operated to
provide refrigeration as required. The compressor is
fitted with cylinder unloaders to match compressor
capacity to the bus requirements. Once interior
temperature reaches the desired set point, the system
may operate in the clutch cycle or reheat mode. A
controller programmed for clutch cycle will
de--energizethecompressorclutchandallowt hesystem
to operate in the vent mode until further cooling is
required. A controller programmed for reheat will
maintain compressor operation and open the heat valve
to allow reheating of the return air. In the reheat mode
interior temperature is maintained at the desired set
point while additional dehumidification takes place.
Controls may also be provided to allow manual
operation of the evaporator fans in low or high speed
andmanualcontrolofthefreshairdamperint he openor
closed position.
1.3 REFRIGERATION SYSTEM COMPONENT
SPECIFICATIONS
a. Refrigerant Charge
R--134a 14.3 lb (6.5 kg)
b. Compressor
UNIT MODEL
GR45 GR60
Compressor 05K 05G
No of Cylinders 4 6
Weight - Dry 108 lbs
(49 kg)
137 lbs
(62 kg)
Oil Charge 5.5 pints
(2.6 liters)
6.75 pints
(3.2 liters)
Oil Level:
Levelin sightglass betweenMin.--Max markson
compressor crankcase (curbside)
Approved Compressor Oils - R-134a:
Castrol: Icematic SW68C
Mobil: EAL Arctic 68
ICI: Emkarate RL68H
c. Thermostatic Expansion Valve:
Superheat Setting (Non-externally adjustable):
10 to 12F
MOP Setting (Nonadjustable): 55 ±4 psig (3.74
±2.27 bar)
d. High Pressure Switch (HPS):
Opens at: 300 ±10 psig (20.41 ±0.68bar)
Closes at: 200 ±10 psig (13.61 ±0.68bar)
e. Low Pressure Switch (LPS)
Opens at: 6 ±3psig (0.41 ±0.20 bar)
Closes at: 25 ±3psig(1.7±0.20 bar)
1.4 ELECTRICAL SPEC IFICA TIONS -- MOTORS
a. Evaporator Fan Motor
Evaporator Motor
ECDC* Permanent
Magnet
p
27.5
VDC
24 VDC 12 VDC
Horsepower (kW) 0.34(.25) 1/8 (.09)
Full Load Amps
(FLA)
8.4 9.5 19
Operating Speed
High/Low (RPM)
4252/
3165
4200/
1850
Bearing Lubrication Factory Lubricated (addi-
tional grease not required)
b. Condenser Fan Motor
Condenser Motor
ECDC* Permanent
Magnet
24 VDC 24 VDC 12 VDC
Horsepower (kW) 0.15(.11) 1/8 (.09)
Full Load Amps
(FLA)
7 9 18
Operating Speed
High/Low (RPM)
4252/
NA
4200/
1850
Bearing Lubrication Factory Lubricated (addi-
tional grease not required)
* Electronically Communicated Direct Current
1.5 ELECTRICAL SPECIFICATIONS -- SENSORS
AND TRANSDUCERS
a. Suction and Discharge Pressure Transducer
Supply Voltage: 4.5 to 5.5 vdc (5 vdc nominal)
Supply current: 8 mA maximum
Output Range: 8K ohms minimum
Input Range: --6.7 to 450 psig (--0.46 to 30.62 bar)
Output Current: -1.5 mA minimum to
1.5 mA maximum
Output Voltage: vdc = 0.0098 x psig + 0.4659
(See Table 4-2 for calculations.)
b. Temperature Sensors
Input Range: --52.6 to 158F ( --47 to 70C)
Output: NTC 10K ohms at 77F(25C)
(See Table 4-1 for calculations.)
1.6 SAFETY DEVICES
System components are protected from damage caused
by unsafe operating conditions with safety devices.
Safety devices with Carrier Transicold supplied
equipment include high pressure switch (HPS ), low
pressure switch (LPS), circuit breakers and fuses.
a. Pressure Switches
High Pressure Switch (HPS)
During the A/C mode, compressor operation will
automatically stop if the HPS switch contacts open due
toanunsafeoperatingcondition.OpeningHPScontacts
de-energizes, through the controller, the compressor
clutchshuttingdown the compressor. Thehigh pressure
switch (HPS) is installed in the center head of the
compressor.