Bard Q60A1 User Manual

Page of 38
Manual
2100-522B
Page
35 of 38
TROUBLESHOOTING  GE  ECM
 MOTORS
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 R to C) at motor
• Check low voltage connections
  (G, Y, W, R, C) at motor
• Check for unseated pins in connectors on
   motor harness
• Test with a temporary jumper between R - G
• Check motor for tight shaft
• Perform motor/control replacement check
• Perform Moisture Check
• Motor rocks,
• Check for loose or compliant motor mount
  but won’t start
• 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 load
& down while being
  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
  (G, Y, W, R, C) 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
• “R” missing/not connected at motor
• Perform motor/control replacement check
• Stays at high CFM
• “R” 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 G, Y or W?
  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
Symptom
Cause/Procedure
• Noisy blower or cabinet
• 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
• “Hunts” or “puffs” at
• Does removing panel or filter reduce
   high CFM (speed)
   “puffing”?
  - Reduce restriction
  - Reduce max. airflow
Evidence of Moisture
• Motor failure or
• Replace motor and Perform Moisture Check
  malfunction has occurred
  
and moisture is present
• Evidence of moisture
• Perform Moisture Check
  present inside air mover
Do
Don’t
• Check out motor, controls,
• Automatically assume the motor is bad.
  wiring and connections
  thoroughly before replacing
  motor
• Orient connectors down so • Locate connectors above 7 and 4 o’clock
  water can’t get in
   positions
 - Install “drip loops”
• Use authorized motor and
• Replace one motor or control model # with
  model #’s for replacement    another (unless an authorized replacement)
• Keep static pressure to a
• Use high pressure drop filters some have ½"
  minimum:
   H20 drop!
 - Recommend high
• Use restricted returns
   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
• Oversize system, then compensate with low
    airflow
• Check orientation before
• Plug in power connector backwards
  inserting motor connectors
• Force plugs
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?