LEESON NEMA 4X SCR Control: 174107.00 - Manual (Page 42)

36 Troubleshooting SPEEDMASTER™ OPERATION MANUAL
Symptom Possible
Causes
Suggested
Solutions
Fuse blows or circuit
breaker trips
Line fuse does not
blow or circuit
breaker does not
trip, but the motor
does not run
1. Line fuses or circuit
breakers are the
wrong size.
2. Motor cable or
armature is shorted to
ground.
3. Nuisance tripping
caused by a
combination of
ambient conditions
and high-current
spikes.
1. Reference signal or
speed adjust pot is set
to zero speed.
2. Reference signal or
speed adjust
potentiometer
connections are open.
1. Check that line fuses
or circuit breakers
are the proper size.
2. Check motor cable
and armature for
shorts.
3. Add a blower to cool
the drive
components;
decrease TORQUE
settings, or resize
motor and drive for
actual load demand,
or check for
incorrectly aligned
mechanical
components or
“jams”. See page 14
for information on
adjusting the
TORQUE trimpot.
1. Increase reference
signal or speed
adjust potentiometer
setting.
2. Check that the
reference signal or
speed adjust
potentiometer
connections are not
open.