Operating instructions

36
ohms. You should then reverse the leads and check again. If
there is no reading or a reading greater than 15,000 ohms, the
start capacitor should be replaced.
START CAPACITOR WITHOUT RESISTOR
Check this style capacitor the same way you would check the
capacitor with the resistor. The reading will be different. The
reading should show continuity and slowly return to infinity.
Reverse the leads and check again. If there is no reading or a
reading of "0" ohms, the start capacitor should be replaced.
The start capacitor must be manually discharged. Using an AC
voltmeter set at the 500 volt scale or higher, connect meter
leads to the terminals of the capacitor. Next, disconnect the
wires to the capacitor. Set the dial-type VOM to the highest
ohm scale and connect the probes to the capacitor terminals.
The reading should rapidly move toward continuity and slowly
return to infinity. Next, reverse the leads and repeat the
procedure. If there is no reading or a prolonged reading,
replace the star capacitor.
4C. PTCR DEVICE OR START RELAY
The positive temperature coefficient resistor, or PTCR has
replaced the compressor start relay and the start capacitor, on
some models. It should be checked in two different ways:
First, check continuity. Turn the air conditioner circuit breaker
to OFF. Disconnect the PTCR from the circuit. Check for
continuity. If there is no continuity, replace PTCR.
THIS IS AN ENERGIZED CIRCUIT. SHOCK CAN OCCUR
IF NOT TESTED PROPERLY. TESTING TO BE DONE BY
A QUALIFIED SERVICE TECHNICIAN.
The second check to take is an amperage reading. Clamp an
ammeter around the wire from the PTCR to the capacitor. Turn
the air conditioner circuit breaker to ON and start the air
conditioner. When the compressor starts, there will be an
amperage reading for approximately one second or less. If
there is no reading, or if there is a prolonged reading, the PTCR
or start relay is faulty and must be replaced.
COMPRESSOR
START RELAY
OHM METER
Open
Circuit –
Device
is Defective
COOL
COMPRESSOR
START
CAPACITOR
5C.COMPRESSOR
To check compressor, turn the air conditioner circuit breaker to
OFF. Disconnect the wires from the COMMON, START and
RUN terminals. With the ohm meter set on the lowest ohm
scale, check for continuity between all three terminals. Lack of
continuity between any of the terminals indicates faulty wind-
ings in the compressor, and the compressor should be re-
placed. Next, scrape some paint off the casing of the compres-
sor and check for continuity between each terminal and the
casing. If a reading is obtained, the windings are shorted to the
casing and the compressor must be replaced.
COMPRESSOR