Bard CH4S1, CH5S1 Troubleshooting GE ECM Motors, Symptom Cause/Procedure, Don’t, Moisture Check

Troubleshooting GE ECM™ Motors

Caution:

Symptom Cause/Procedure

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.

• 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

Symptom

Motor rocks slightly when starting

Cause/Procedure

• This is normal start-up for ECM

• “Hunts” or “puffs” at

high CFM (speed)

• Does removing panel or filter reduce

“puffing”?

- Reduce restriction

- Reduce max. airflow

Motor won’t start

• No movement

• Check blower turns by hand

• 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

Evidence of Moisture	• Replace motor and Perform Moisture Check
• Motor failure or
malfunction has occurred
and moisture is present
• Evidence of moisture	• Perform Moisture Check
present inside air mover

• Check motor for tight shaft

• Perform motor/control replacement check

• Perform Moisture Check

Do

• Check out motor, controls,

wiring and connections

thoroughly before replacing

Don’t

• Automatically assume the motor is bad.

•Motor rocks, but won’t start

Motor oscillates up

&down while being tested off of blower

Motor starts, but runs erratically

•Varies up and down or intermittent

•Check for loose or compliant motor mount

•Make sure blower wheel is tight on shaft

•Perform motor/control replacement check

•It is normal for motor to oscillate with no load on shaft

•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 “Bk” for erratic CFM command (in variable-speed applications)

•Check out system controls, Thermostat

•Perform Moisture Check

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

• 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

• “Hunts” or “puffs” at	• Does removing panel or filter reduce
high CFM (speed)	“puffing”?
	- Reduce restriction
	- Reduce max airflow

• Size the equipment wisely

• Check orientation before

inserting motor connectors

•Oversize system, then compensate with low airflow

•Plug in power connector backwards

•Force plugs

Moisture Check

•Stays at low CFM despite system call for cool or heat CFM

•Stays at high CFM

•Blower won’t shut off

Excessive noise

• Air noise

•Check low voltage (Thermostat) wires and connections

•Verify fan is not in delay mode; wait until delay complete

•“R” missing/not connected at motor

•Perform motor/control replacement check

•“R” missing/not connected at motor

•Is fan in delay mode? - wait until delay time complete

•Perform motor/control replacement check

•Current leakage from controls into G, Y or W?

Check for Triac switched thermostat or solid- state relay

•Determine if it’s air noise, cabinet, duct or motor noise; interview customer, if necessary

•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

•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?

Manual 2100-455M

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