Cooling - Piper Dakota Maintenance Manual

COOLING

DESCRIPTION AND OPERATION
The air conditioning system comprises a compressor and special brackets, evaporator, condenser, receiver-
dehydrator, circulating fan, thermal expansion valve, and related plumbing.
The evaporator is mounted in a fabricated housing along with the receiver- d e h y d r a t o r, circulating fan,
thermal expansion valve and related plumbing. This housing is located aft of baggage area. The compressor is
supported by special brackets at front of engine. A V-belt connected to engine ring gear drives compressor
through a magnetic clutch. The condenser is installed on a hinge mounted door located on bottom portion of
fuselage tail section. The condenser door is hinge mounted to allow extension into airstream during system
operation. The condenser door is electrically activated to fully extend system on or fully retract system off.
A Ranco type pressure switch automatically controls condenser maximum head pressure by temporarily
de-clutching the compressor in event pressure becomes excessively high. The controls are located on the
aircraft instrument panel adjacent to heater and defroster levers, and consist of an air conditioning control, a
fan control, and a temperature control.
This aircraft's air conditioning system is a recirculating, independent unit. Air is filtered, dehumidified and
cooled as it cycles through the evaporator. The air conditioning master switch is a two position on-off switch,
When AIR COND position is selected the compressor clutch engages, condenser scoop opens and circulating
fan is turned on. Temperature is controlled by a thermostat operated by the temperature control selector. A
three position fan switch LOW-OFF-HIGH operates blower. The fan may be operated to circulate air without
using the air conditioning unit.
The air conditioning system should be operated at least once a
month to lubricate the system and prevent sticking valves
PIPER AIRCRAFT
PA-28-236
MAINTENANCE MANUAL
—NOTE—
1F17
21 - 52 - 00
Page - 21 - 03
Reissued: August 1, 1986