GSZH5 Service Manual
84
SERVICING
Symptom
Possible Causes Corrective Action Cautions and Notes
- Motor rocks
slightly
w hen starting.
- This is normal start-up f or
variable speed motor.
---- ---- ----
- No movement.
- Manual disconnect sw itch of f or
door sw itch open.
- Blow n f use or circuit breaker.
- 24 Vac w ires misw ired.
- Unseated pins in w iring
harness connectors.
- Bad motor/control module.
- Moisture present in motor or control module.
- Check 230 Vac pow er at motor.
- Check low voltage (24 Vac R to C) at motor.
- Check low voltage connections
(G, Y, W, R, C) at motor.
- Check f or unseated pins in connectors
on motor harness.
- Test w ith a temporary jumper betw een R - G.
-
- Turn pow er OFF prior to repair.
Wait 5 minutes after
disconnecting pow er bef ore
opening motor.
- Handle electronic motor/control w ith care.
- Motor rocks,
but w on't start.
- Loose motor mount.
- Blow er w heel not tight on motor shaft.
- Bad motor/control module.
- Check f or loose motor mount.
- Make sure blow er w heel is tight on shaft.
- Perform motor/control replacement check,
ECM motors only.
- Turn pow er OFF prior to repair.
Wait 5 minutes after
disconnecting pow er bef ore
opening motor.
- Handle electronic motor/control w ith care.
- Motor
oscillates up &
dow n w hile
being tested
off of blow er.
- It is normal for motor to
oscillate w ith
no load on shaf t.
----
---- ----
- Varies up and dow n
or intermittent.
- Variation in 230 Vac to motor.
- Unseated pins in w iring harness
connectors.
- Erratic CFM command from
"BK" terminal.
- Improper thermostat connection or setting.
- Moisture present in motor/control module.
- Check line voltage for variation or "sag".
- Check low voltage connections
(G, Y, W, R, C) at
motor, unseated pins in motor
harness connectors.
- Check-out system controls - Thermostat.
- Perform Moisture Check.*
- Turn pow er OFF prior to repair.
- "Hunts" or "puffs" at
high CFM (speed).
- Incorrect or dirty filter(s).
- Incorrect supply or return ductw ork.
- Incorrect blow er speed setting.
- Does removing panel or filter
reduce "puf fing"?
- Check/replace filter.
- Check/correct duct restrictions.
- Adjust to correct blow er speed setting.
- Turn pow er OFF prior to repair.
- Motor w on't
start.
- Motor starts,
but runs
erratically.
- Connectors are oriented "down" (or as recommended by equipment manufacturer). - Arrange harnesses with "drip loop" under motor.
- Is condensate drain plugged? - Check for low airflow (too much latent capacity).
- Check for undercharged condition. - Check and plug leaks in return ducts, cabinet.
Using the wrong motor/control module voids all product warranties and may produce unexpected results.
You must use the correct replacement control/motor module since they are factory programmed for specific operating modes. Even though they look alike, different modules may have completely different
functionality. The ECM variable speed motors are c
CHART CONTINUED ON NEXT PAGE