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SERVICING
44
- Connectors are oriented "down"
(
or as recommended b
y
equipment manufacturer
)
.- Arran
g
e harnesses with "drip loop" under motor.
-
I
s con
d
ensa
t
e
d
ra
i
n p
l
u
gg
e
d?
-
Ch
ec
k
f
or
l
ow a
i
r
fl
ow
(t
oo muc
h
l
a
t
en
t
capac
ity)
.
-
Check
for
undercharged
condition
. -
Check
and
plug
leaks
in
return
ducts
,
cabinet
.
*Moisture Check
I
mpor
t
an
t
N
o
t
e:
U
s
i
n
g
th
e wron
g
mo
t
or
/
con
t
ro
l
mo
d
u
l
e vo
id
s a
ll
pro
d
uc
t
warran
ti
es an
d
ma
y
pro
d
uce unexpec
t
e
d
resu
lt
s.
Note:
You must use the correct replacement control/motor module since the
y
are factor
y
pro
g
rammed for specific operatin
g
modes. Even thou
g
h the
y
look alike, different modules ma
y
have completel
y
different
functionality. The ECM variable speed motors are c
CHART CONTINUED ON NEXT PAGE
Symptom Fault Description(s) Possible Causes Corrective Action Cautions and Notes
- Motor rocks
slightly
when starting.
- This is normal start-up for
variable speed motor.
---- ---- ----
- No movement.
- Manual disconnect switch off or
door switch open.
- Blown fuse or circuit breaker.
- 24 Vac wires miswired.
- Unseated pins in wiring
harness connectors.
- Bad motor/control module.
- Moisture present in motor or control module.
- Check 230 Vac 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.
- Turn power OFF prior to repair.
Wait 5 minutes after
disconnecting power before
opening motor.
- Handle electronic motor/control with care.
- Motor rocks,
but won't start.
- Loose motor mount.
- Blower wheel not tight on motor shaft.
- Bad motor/control module.
- Check for loose motor mount.
- Make sure blower wheel is tight on shaft.
- Perform motor/control replacement check,
ECM motors only.
- Turn power OFF prior to repair.
Wait 5 minutes after
disconnecting power before
opening motor.
- Handle electronic motor/control with care.
- Motor
oscillates up &
down while
being tested
off of blower.
- It is normal for motor to
oscillate with
no load on shaft.
---- ---- ----
- Varies up and down
or intermittent.
- Variation in 230 Vac to motor.
- Unseated pins in wiring 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 power OFF prior to repair.
- "Hunts" or "puffs" at
high CFM (speed).
- Incorrect or dirty filter(s).
- Incorrect supply or return ductwork.
- Incorrect blower speed setting.
- Does removing panel or filter
reduce "puffing"?
- Check/replace filter.
- Check/correct duct restrictions.
- Adjust to correct blower speed setting.
- Turn power OFF prior to repair.
Troubleshooting Chart for ECM Variable Speed Air Circulator Blower Motors
- Motor won't
start.
- Motor starts,
but runs
erratically.