Energy Tech Laboratories DSH Maintenance / Service, Filters, Evaporator And Condenser Coils

FORM 145.32-IOM1 (908)

MAINTENANCE / SERVICE

Disconnect And Lock Out Power When Servicing Unit. Failure To Do So May Result In Personal Injury Or Death Due To Electrical Shock.

Exercise care when working around the sharp metal edges of door panels or door frames, etc. These edges can cause injury.

FILTERS

Inspect filters monthly and replace as necessary. Use UL Class 2 rated filters. Factory supplied filters are medium efficiency, extended surface pleated type. Replacements should be of the same type, to maintain optimum airflow performance. Filter sizes are as follows:

FILTERS	2 TON	3 TON
QTY / SIZE	2 / 20 x 14 x 2	2 / 20 x 14 x 2
FILTERS	4 TON	5 TON
QTY / SIZE	2 / 25 x 16 x 2	2 / 25 x 16 x 2

EVAPORATOR AND CONDENSER COILS

Inspect the evaporator coil at filter change intervals. Inspect the condenser coil at least semi-annually. A dirty condenser coil will result in elevated condensing pressures and poor unit performance. Dirty or clogged evaporator coils cause low suction pressure and lost capacity. If the coils appear dirty, clean them using mild detergent or a commercial coil cleaning agent.

BLOWERS

Inspect both the evaporator and condenser blowers at each regular service interval. Clean blower wheels as needed. Bearings are permanently sealed ball type, and do not require lubrication. Check bearings for any signs of wear (movement between inner and outer races). En- sure bearing locking collars are secure to the shaft, and that collar locking screw is properly set. Check that the blower wheel is tight on the shaft, and that the setscrews in the blower hub are properly torqued.

DRIVE BELTS

Examine belts periodically for wear. Glazed areas on the drive surfaces indicate overheating due to belt slippage. Ideal tension is the lowest tension at which the belt will not slip under peak load conditions. Over-tensioning shortens belt and bearing life.

The tension on the belt should be adjusted for a deflec- tion of 1164 of an inch per inch of belt span, with the ap- propriate force applied at the midpoint of the span. Ten- sion “New” belts at the maximum value indicated. Used belts should be maintained at the minimum value.

	POUNDS FORCE
Belt Cross Section	Min.	Max.
4L	1-1/2	2-1/2
A	3-1/2	6-1/2
B	5-1/2	8
BX	8	11

REFRIGERANT CIRCUIT(S)

With the unit operating, check and record the compres- sor discharge and suction pressures. The compressor running current should also be recorded. A maintenance log of these readings can indicate if the unit is operating within its normal limits. Abnormal readings should be investigated, and the cause corrected.

Johnson Controls 17