Ecm Tm Motors; Manual 2100-587J - Bard WG Series Installation Instructions Manual

Troubleshooting 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 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
and 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
(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
™
Motors
Symptom
• Air noise
• Noisy blower or cabinet • Check for loose blower housing, panels, etc.
• "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 • Locate connectors above 7 and 4 o'clock
so water can't get in
- Install "drip loops"
• Use authorized motor
and model #'s for
replacement
• Keep static pressure to a • Use high pressure drop filters some have ½"
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 • Oversize system, then compensate with
• 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?
Cause/Procedure
• 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
• 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.
positions
• Replace one motor or control model # with
another (unless an authorized replacement)
H20 drop!
• Use restricted returns
low airflow
Manual 2100-587J
Page 43 of 59