Testing The Reversing Valve Solenoid Coil - Friedrich PTAC ZONEAIRE SELECT Service & Parts Manual

Testing The Reversing Valve Solenoid Coil

The solenoid coil is an electromagnetic type coil mounted on the reversing valve and is energized during the
operation of the compressor in the heating cycle.
1. Turn off high voltage electrical power to unit.
2. Unplug line voltage lead from reversing valve coil.
3. Check for electrical continuity through the coil. If you do not have continuity replace the coil.
4. Check from each lead of coil to the copper liquid line as it leaves the unit or the ground lug. There should be no
continuity between either of the coil leads and ground; if there is, coil is grounded and must be replaced.
5. If coil tests okay, reconnect the electrical leads.
6. Make sure coil has been assembled correctly.
NOTE: Do not start unit with solenoid coil removed from valve, or do not remove coil after unit is in operation.
This will cause the coil to burn out.
Touch Test in Heating/Cooling Cycle
The only definite indications that the slide is in the mid-position is if all three tubes on the suction side of the valve
are hot after a few minutes of running time.
NOTE: If both tubes shown as hot or cool are not the same corresponding temperature, refer to figure 703, then
the reversing valve is not shifting properly.
49
COMPONENT TESTING
WARNING
ELECTRIC SHOCK HAZARD
Disconnect power to the unit before
servicing. Failure to follow this warning
could result in serious injury or death.
WARNING
BURN HAZARD
Certain unit components operate at
temperatures hot enough to cause burns.
Proper safety procedures must be followed,
and proper protective clothing must be
worn.
Failure to follow these procedures could
result in minor to moderate injury.
WARNING
Proper safety procedures must be followed, BURN HAZARD
when working with a torch. and proper protective clothing must be worn
result in moderate or serious injury. Failure to follow these procedures could