Whirlpool ATE0743RPP, Technical Manual

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6-5
With a complete restriction, there will be no
sound at the capillary tube entrance. An am-
perage check of the compressor with a partial
restriction may show normal current when com-
pared to the unit specification. The current
drawn may be considerably less than normal,
since the compressor is running in a deep
vacuum (no load). Much of the area of the
condenser will be relatively cool, since most, or
all of the liquid refrigerant will be stored there. CAPILLARY TUBE RESTRICTIONS
All Whirlpool PTAC units are equipped with
capillary tubes. When checking for a restricted
capillary tube, use the following procedure.
1. Connect pressure gauges to the unit.
2. Start the unit in the “cooling” mode. If the
pressures are normal after a few minutes of
operation, the check valve and cooling cap-
illary are not restricted.
3. Switch the unit to the “heating” mode, and
observe the gauge readings after a few
minutes of running time. If the system pres-
sure is lower than normal, the heating cap-
illary is restricted.
4. If the operating pressures are lower than
normal in both the heating and cooling
modes, the cooling capillary is restricted.
Completely Restricted System