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Electrical Maintenance
88
5. If the switch is out of calibration, pressurize
the hose again until the tester indicates
0.70 in. (17.8 mm) H
2
O. Adjust the screw
clockwise or counterclockwise until the
switch closes and the continuity tester
indicates a completed circuit with the gauge
reading 0.70 in. (17.8 mm) H
2
O. Release the
pressure.
6. Repeat test procedure several times to be sure
the setting is correct.
7. Remove the test equipment. Install wire on
switch terminal and air sensing tubes on air
switch. The BLACK hose from the high
pressure or air inlet side of the evaporator coil
goes on the hose fitting on the side of the air
switch stamped BLACK. The CLEAR hose
from the low pressure or air outlet side of the
evaporator coil goes on the hose fitting on the
side of the air switch stamped CLEAR.
NOTE: Route hoses for continuous slope to
avoid condensate traps.
If too much frost continues to accumulate before
defrost, decrease the pressure setting. Turn the
adjustment screw counterclockwise.
If defrost action occurs with too little frost
accumulation, increase the pressure setting. Turn
the adjustment screw clockwise.
High Capacity TherMax
TM
Heating System
The high capacity heating system increases the
capacity of the Heat mode by making more
refrigerant available for use in the Heat mode.
This is accomplished by adding an additional
solenoid (TherMax
TM
solenoid) to the
refrigeration system which opens during the
beginning of the Heat mode to move the liquid
refrigerant from the condenser to the accumulator
where it can be used in the Heat mode. The
sequence of operation for the improved heating
system is from the Cool mode to the Heat mode
with Refrigerant Transfer mode to the Heat mode.
The Heat mode to Cool mode operation is the
same as in the past. The bypass check valve, and
the condenser check valve have been eliminated
from the TherMax
TM
heating system.
The components that have been added to the
system are:
•
the TherMax
TM
solenoid
•
the TherMax
TM
solenoid line
•
the receiver outlet check valve
The TherMax
TM
solenoid controls the flow of
refrigerant through the TherMax
TM
solenoid line.
The TherMax
TM
solenoid line goes from the liquid
1.
Magnetic Pressure Gauge
2.
Squeeze Bulb Tool
3.
Continuity Tester
Figure 14: Testing Air Switch
1.
Adjustment Screw
Figure 15: Air Switch
Summary of Contents for 914970
Page 3: ...3...
Page 10: ...Table of Contents 10...
Page 40: ...Operating Instructions 40...
Page 82: ...Electronic Controls 82...
Page 92: ...Electrical Maintenance 92...
Page 124: ...Refrigeration Maintenance 124...
Page 140: ...Hilliard Clutch Maintenance 140...
Page 160: ...Refrigeration Diagrams 160...
Page 163: ...Index 163 W wiring 85 wiring diagrams 165...
Page 164: ...Index 164...
Page 166: ...Wiring and Schematic Diagrams Index 166...
Page 167: ...167 Cab Control RD Wiring Diagram...
Page 168: ...168 RD w o Thermostat Cab Control Schematic...
Page 169: ...169 RD Cab Box Wiring Diagram...
Page 170: ...170 RD Cab Control w Thermostat Schematic Diagram...
Page 171: ...171 RD 50 STD 3 Phase Wiring Diagram Page 1 of 2...
Page 172: ...172 RD 50 STD 3 Phase Wiring Diagram Page 2 of 2...
Page 173: ...173 RD 50 STD 3 Phase Schematic Diagram Page 1 of 2...
Page 174: ...174 RD 50 STD 3 Phase Schematic Diagram Page 2 of 2...
Page 175: ...175 RD 30 STD Wiring Diagram Page 1 of 2...
Page 176: ...176 RD 30 STD Wiring Diagram Page 2 of 2...
Page 177: ...177 RD 30 STD Schematic Diagram Page 1 of 2...
Page 178: ...178 RD 30 STD Schematic Diagram Page 2 of 2...
Page 179: ...179 RD 30 C S Wiring Diagram Page 1 of 2...
Page 180: ...180 RD 30 C S Wiring Diagram Page 2 of 2...
Page 181: ...181 RD w CYCLE SENTRY Schematic Diagram Page 1 of 2...
Page 182: ...182 RD w CYCLE SENTRY Schematic Diagram Page 2 of 2...
Page 183: ...183 RD 50 C S 3 Phase Wiring Diagram Page 1 of 2...
Page 184: ...184 RD 50 C S 3 Phase Wiring Diagram Page 2 of 2...
Page 185: ...185 RD w CYCLE SENTRY Schematic Diagram Page 1 of 2...
Page 186: ...186 RD w CYCLE SENTRY Schematic Diagram Page 2 of 2...