Capacitance Check (Mfd); Checking Fan And Blower Motor Windings (Psc Motors); Checking Ecm Motor Windings - Daikin APGM3 Service And Troubleshooting

SERVICING
Testing Start Relay Contacts

Capacitance Check (MFD)

Discharge capacitor through a 20 to 30 OHM resistor
before handling.
1. Turn power off to unit.
2. Discharge capacitor through a 20Ω - 30Ω resistor.
3. Remove wires from capacitor.
4. Use multi-meter check micro-farads (MFD) of the
capacitor.
5. Place leads from C – HERM.
6. Place leads from C – FAN.
7. Compare to capacitor rating label. If the reading is
within the tolerance listed on rating label the capacitor
is good. If the reading is lower, the capacitor is bad
and must be replaced.
Testing Capacitance
WARNING
Checking Fan And Blower Motor Windings
(PSC Motors)
The auto reset fan motor overload is designed to protect
the motor against high temperature and high amperage
conditions by breaking the common circuit within the motor,
similar to the compressor internal overload. However, heat
generated within the motor is faster to dissipate than the
compressor, allow at least 45 minutes for the overload to
reset, then retest.
High Voltage!
Disconnect all power before servicing or
installing. Multiple power sources may be
present. Failure to do so may cause property
damage, personal injury or death.
1. Remove the motor leads from its respective
connection points and capacitor (if applicable).
2. Check the continuity between each of the motor leads.
3. Touch one probe of the ohmmeter to the motor frame
(ground) and the other probe in turn to each lead.
If the windings do not test continuous or a reading is
obtained from lead to ground, replace the motor.

Checking ECM Motor Windings

High Voltage!
Disconnect all power before servicing or
installing. Multiple power sources may be
present. Failure to do so may cause property
damage, personal injury or death.
1. Disconnect the 5-pin and the 16-pin connectors from
the ECM power head.
2. Remove the 2 screws securing the ECM power head
and separate it from the motor.
3. Disconnect the 3-pin motor connector from the power
head and lay it aside.
4. Using an ohmmeter, check the motor windings for
continuity to ground (pins to motor shell). If the
ohmmeter indicates continuity to ground, the motor is
defective and must be replaced.
5. Using an ohmmeter, check the windings for continuity
(pin to pin). If no continuity is indicated, the thermal
limit (over load) device may be open. Allow motor to
cool and retest.
WARNING
WARNING
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