Troubleshooting Ge Ecm Tm Motors - Bard HA4S4KA Installation Instructions Manual

TROUBLESHOOTING GE ECM
CAUTION:
Disconnect power from unit before removing or replacing
connectors, or servicing motor. To avoid electric shock
from the motor's capacitors, disconnect power and wait at
least 5 minutes before opening motor.
Symptom Cause/Procedure
Motor rocks slightly • This is normal start up for ECM
when starting
Motor won't start • Check blower turns by hand
• No movement
• Check power at motor
• Check low voltage (24 Vac 2 to 3) at
motor
• Check low voltage connections
(9, 4, 6, 2, 3) at motor
• Check for unseated pins in connectors on
motor harness
• Test with a temporary jumper between 2
- 9
• Check motor for tight shaft
• Perform motor/control replacement check
• Perform Moisture Check
• Motor rocks, • Check for loose or compliant motor
but won't start mount
• Make sure blower wheel is tight on shaft
• Perform motor/control replacement check
Motor oscillates up • It is normal for motor to oscillate with no
& down while being load on shaft
tested off of blower
Motor starts, but
runs erratically
• Varies up and down • Check line voltage for variation or "sag"
or intermittent • Check low voltage connections
(9, 4, 6, 2, 3) at motor, unseated pins in
motor harness connectors
• Check "Bk" for erratic CFM command (in
variable-speed applications)
• Check out system controls, Thermostat
• Perform Moisture Check
• "Hunts" or "puffs" at • Does removing panel or filter reduce
high CFM (speed) "puffing"?
- Reduce restriction
- Reduce max airflow
• Stays at low CFM • Check low voltage (Thermostat) wires and
despite system call connections
for cool or heat CFM • Verify fan is not in delay mode; wait until
delay complete
• "2" missing/not connected at motor
• Perform motor/control replacement check
• Stays at high CFM • "2" missing/not connected at motor
• Is fan in delay mode? - wait until delay
time complete
• Perform motor/control replacement check
• Blower won't shut off • Current leakage from controls into 9, 4 or
6?
• Check for Triac switched thermostat or
solid-state relay
Excessive noise • Determine if it's air noise, cabinet, duct
or motor noise; interview customer, if
necessary
• Air noise • High static creating high blower speed?
- Is airflow set properly?
- Does removing filter cause blower to slow
down? Check filter
- Use low-pressure drop filter
- Check/correct duct restrictions
Manual 2100-646
Page 20 of 26
MOTORS
TM
Symptom
• Noisy blower or cabinet
• "Hunts" or "puffs" at
high CFM (speed)
Evidence of Moisture
• Motor failure or
malfunction has occurred
and moisture is present
• Evidence of moisture
present inside air mover
Do
• Check out motor, controls,
wiring and connections
thoroughly before replacing
motor
• Orient connectors down so
water can't get in
- Install "drip loops"
• Use authorized motor and
model #'s for replacement
• Keep static pressure to a
minimum:
- Recommend high
efficiency, low static filters
- Recommend keeping filters
clean.
- Design ductwork for min.
static, max. comfort
- Look for and recommend
ductwork improvement,
where necessary
• Size the equipment wisely
• Check orientation before
inserting motor connectors
Moisture Check
• Connectors are oriented "down" (or as recommended by equipment
manufacturer)
• Arrange harness 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
Comfort Check
• Check proper airflow settings
• Low static pressure for lowest noise
• Set low continuous-fan CFM
• Use humidistat and 2-speed cooling units
• Use zoning controls designed for ECM that regulate CFM
• Thermostat in bad location?
Cause/Procedure
• Check for loose blower housing,
panels, etc.
• High static creating high blower
speed?
- Check for air whistling through seams
in ducts, cabinets or panels
- Check for cabinet/duct deformation
• Does removing panel or filter reduce
"puffing"?
- Reduce restriction
- Reduce max. airflow
• Replace motor and Perform Moisture
Check
• Perform Moisture Check
Don't
• Automatically assume the motor is
bad.
• Locate connectors above 7 and 4
o'clock positions
• Replace one motor or control model
# with another (unless an authorized
replacement)
• Use high pressure drop filters some
have ½" H20 drop!
• Use restricted returns
• Oversize system, then compensate
with low airflow
• Plug in power connector backwards
• Force plugs