LIQUID TEMPERATURE AT LIQUID VALVE (C)
60
54
49
43
38
32
27
21
16
10
Fig. 19A — 575B072 Charging Chart
| 140 | |
(F) | 130 | |
ADD CHARGE IF ABOVE CURVE | ||
VALVE | ||
120 | ||
| ||
AT LIQUID | 110 | |
100 | ||
TEMPERATURE | ||
90 | ||
80 | ||
| ||
LIQUID | 70 | |
REDUCE CHARGE IF BELOW CURVE | ||
| 60 | |
| 50 |
50 | 100 | 150 | 200 | 250 | 300 | 350 | 400 | ||
|
|
| LIQUID PRESSURE AT LIQUID VALVE (PSIG) |
|
|
| |||
344 | 689 | 1034 | 1379 | 1724 | 2069 | 2414 |
|
| |
|
|
| LIQUID PRESSURE AT LIQUID VALVE (Kilopascals) |
|
|
|
Fig. 19B — 575C090,120 Charging Chart
Fig. 19C — 541A180 Charging Chart
SEQUENCE OF OPERATION
I. 575B072 UNITS
When power is supplied to unit, the transformer (TRAN) and crankcase heater (CCH) are energized.
A. Cooling
On a call for cooling, the thermostat completes the following circuits:
When the thermostat is satisfied, the circuits are opened, and the compressor,
B. Heating
On a call for heating, the thermostat completes the following circuits:
If room temperature continues to fall, the thermostat completes circuit
When the thermostat is satisfied, the circuits are opened, and the compressor,
C. Defrost
Defrost board (DB) is a time and temperature control, which includes a
Defrost mode is identical to Cooling mode, except
D. Air Circulation
When the fan switch is at FAN ON, the
E. Emergency Heat Cycle
If the compressor is inoperative due to a tripped safety device, the second stage of the thermostat automatically energizes the
II. 575C090,120 UNITS
When power is supplied to unit, the transformer (TRAN) is energized. The crankcase heater is also energized.
A. Cooling
With the thermostat subbase in the cooling position, and when the space temperature comes within 2° F of the cooling set point, the thermostat makes circuit
As the space temperature continues to rise, the second stage of the thermostat makes, closing circuit