Replace the ®lter cores whenever the moisture/liquid in- dicator shows moisture in the system.
Follow instructions on the packaging for the replacement cores for disassembling and reassembling the ®lter assem- blies and housings.
Liquid Line Service Valve Ð Located immediately ahead of the ®lter drier, this valve has a
Compressor Suction and Discharge Service Valves Ð Each compressor is provided with suction and discharge service valves. With these valves, the compressor can be isolated from the refrigerant system for servicing or replacing.
Table 31 Ð Pressure Switch Settings,
Psig (kPag)
SWITCH | CUTOUT | ||||
High | 426 | ± 7 | 320 | ± 20 | |
(2935 | ± 48) | (2205 | ± 138) | ||
| |||||
Low | 27 | ± 4 | 67 ± 7 | ||
(186 ± 28) | (462 | ± 48) | |||
|
NOTE:
TO CHECK Ð Slowly close the discharge shutoff valve until the compressor shuts down. This should be at approx- imately 426 psig (2935 kPag). Slowly open the valve. When the pressure drops to approximately 320 psig (2205 kPag), the pressure switch resets. To reenergize the control circuit, manually switch the fan circuit breaker off and then on. The compressor starts again under Time Guard controls.
TO CHECK Ð Slowly close the suction
Pressure Relief Ð
Adjustments
EVAPORATOR FAN AND POWER EXHAUST MOTOR PLATE Ð Adjust using a
1.Loosen holddown bolts. (See Fig. 61.)
2.Turn the adjusting bolts to move the motor mounting plate toward or away from the fan to loosen or tighten the belts. Make the same number of turns to each bolt.
3.Retighten holddown bolts.
BELT INSTALLATION AND TENSIONING
IMPORTANT: When installing or replacing belts, al- ways use a complete set of new, matched belts to pre- vent potential vibration problems. Mixing belts often results in premature breakage of the new belts.
1.Turn off unit power.
2.Adjust motor plate so belts can be installed without stretch- ing over the grooves of the pulley. (Forcing the belts can result in uneven belt stretching and a mismatched set of belts.)
3.Before tensioning the belts, equalize belt slack so that it is on the same side of the belt for all belts. Failure to do so may result in uneven belt stretching.
4.Tighten belts using the motor plate adjusting bolts.
5.Adjust until proper belt tension
NOTE: Check the tension at least twice during the ®rst day of operation, as there is normally a rapid decrease in tension until the belts have run in. Check tension periodically thereafter and keep it at the recommended tension.
With the correct belt tension, belts may slip and squeal momentarily on
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