Filter
Top Products
4-4 T
roubleshooting
Indication
Possible Cause
Corrective Action
MIN. Output Frequency
Limit set too high
Adjust setting of Min. Output
Frequency Limit
Motor will
not stop
Improper speed command
V
erify control is receiving proper
command signals at the control
terminal strip
not
sto
rotation
V
erify control is set to receive your
type of speed command
Speed potentiometer
failure
Replace potentiometer
Oscillating load
Correct the loading problem
Unstable
Unstable input power Correct the input power problem
Unstable
motor speed
Slip compensation set too
high
Adjust slip compensation
Motor runs
T
orque boost set too high
Adjust torque boost setting
Motor runs
rough at low
s
p
eeds
Misalignment of
motor/load coupling
V
erify and align motor/load
coupling
spee
d
s
Defective motor
Replace motor
.
Clean the motor air intake and
exhaust areas
Insuf
ficient motor
ventilation
Check external blower for proper
operation
ventilation
V
erify motor
’
s internal fan is
securely coupled to shaft
External trip
Motor drawing excessive
Check for excessive motor load
External trip
fault
M
otor
d
raw
i
ng excess
i
ve
current
V
erify proper motor and control
rating
V
olts/Hertz ratio not
Adjust V/Hz profile
V
olts/Hertz ratio not
adjusted
Adjust control base frequency
a
dj
us
t
e
d
Adjust Max. Output V
olts
Connect thermostat
No thermostat connected
V
erify connection of all external trip
circuits used with thermostat
Over current
Accel/Decel rate set too
quickly
Increase Accel/Decel rate
Over
current
T
orque boost set too high
Reduce torque boost setting
Timed
overload
Motor overloaded
V
erify proper motor and control
rating
overload
fault
Correct the loading problem