Subject to change without notice. Printed in U.S.A.
Copyright
©
by Unitary Products Group 2003. All rights reserved.
Supersedes: Nothing
036-21540-001-A-0503
Unitary
5005
Norman
Products
York
OK
Group
Drive
73069
MAINTENANCE / SERVICE
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 fol-
lows:
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). Ensure 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 hub setscrews are properly torqued.
DRIVE BELTS
Examine belts periodically for wear. Glazed areas on
the drive surfaces indicate overheating due to belt slip-
page. Ideal tension is the lowest tension at which the
belt will not slip under peak load conditions. Over-ten-
sioning shortens belt and bearing life.
The tension on the belt should be adjusted for a deflec-
tion of 1/64 of an inch per inch of belt span, with the
appropriate force applied at the midpoint of the span.
Tension “New” belts at the maximum value indicated.
Used belts should be maintained at the minimum
value.
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 read-
ings should be investigated, and the cause corrected.
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
3 TON
4 TON
5 TON
8 TON
1 0 TON
12 TON
15 TON
20 TON
25 TON
Qty/Size
2/18x24x2 2/18x24x2 2/18x24x2 4/14x25x2 4/14x25x2
2/14x20x2
4/14x25x2
2/14x20x2
4/14x25x2
6/20x25x2 8/20x20x2
FIGURE 10 - BELT ADJUSTMENT
