Electrical, Refrigeration and
µ
P-D Menu Flow Diagrams
Refrigeration Schematic: Full Cool
9-38
CSR-20 & CSR-40, September 1999
Flow and Pressure Diagram
CSR-20 & CSR-40
Full Cool
1.
Scroll Compressor
Compressor operation has a delay on initial start-up when the unit
shifts to a cooling mode requiring the compressor to start-up.
2.
Compressor Discharge (Head) Temperature Sensor (CHS1)
Controller cycles condenser fan ON typically when the compressor
discharge temperature is above 50 C (122 F) and increasing.
3.
High Pressure Cutout Switch (HPCO)
Is a normally CLOSED switch.
It OPENS at 3240 +/- 50 kPa, 32.4 +/- 0.5 bar, 470 +/- 7 psig.
It CLOSES at 2590 +/- 260 kPa, 25.9 +/- 2.6 bar, 375 +/- 38 psig.
8.
High Pressure Relief Valve
OPENS at 3450 +520/-105 kPa, 34.5 +5.20/-1.05 bar, 500 +75/-15
psig.
CLOSES at 2760 kPa, 27.6 bar, 400 psig.
24. Condenser Coil Temperature Sensor (CCOIL)
Controller cycles condenser fan ON typically when the condenser coil
temperature is above 35 C (95 F).
25. Controller (
µµ
P-D)
Thermoguard (
µ
P-D) with digital thermostat, thermometer and fault
indicator monitor.
Null Mode Operation
During the Null mode, the compressor does not operate. If the con-
denser fan is ON when the unit shifts to Null, the condenser fan oper-
ates for 30 seconds and stops. Evaporator fans continue to operate
(evaporator fan speed is determined by return air temperature and
economy mode setting).
29. Water Pressure Switch (WPS) (Option)
Is a normally CLOSED switch.
It OPENS at 117 +/- 21 kPa, 1.17 +/- 0.21 bar, 17 +/- 3 psig.
It CLOSES at 35 +/- 21 kPa, 0.35 +/- 0.21 bar, 5 +/- 3 psig.
High pressure gas
High pressure liquid
Low pressure gas
Low pressure liquid
Condensing high pressure gas
Low pressure vaporizing liquid
Liquid refrigerant injection
