10
SERVICE 
Capacity Control –A suction pressure-actuated unloader controls 2 cylinders and provides 
capacity control. Unloaders are factory set (see Tables l.), but can be field adjusted as described in 
the 2 following sections. 
Time Guard ll Circuit
 – Prevents short – cycling by providing a delay of approximately 5 minutes 
before restarting compressor after shutdown from safety device action. 
On start-up, the Time Guard II time causes a delay of approximately 3 seconds after thermostat 
closes.
On compressor shutdown, the time recycles for approximately 5 minutes. During this time, the 
compressor cannot restart. 
Refer to Fig. 8 and to label diagram on unit. 
F
ig.8 - Timer Sequence chart 
Crankcase Heater – The heater prevents refrigerant migration and compressor oil dilution during 
shutdown whenever compressor is not operating. It is wired into the control circuit. and cycles with  
the compressor; the heater is off when compressor is running ,and on when compressor is off. 
Both compressor service valves must be closed whenever the crankcase heater is for more than 6 
hours. The crankcase heater is operable as long as the control circuit is energized. 
Outdoor Fans – Each fan is supported by a formed wire mount bolted to the fan deck and covered 
with a wire guard. The exposed end of the motor shaft is covered with a rubber boot. In case a fan 
motor must be repaired or replaced, be sure the rubber boot is put back on when the fan is 
reinstalled and be sure the fan guard is in place before starting the unit. Fan motors have 
permanently lubricated bearings.