Zener MSC-3 Instruction Manual page 151

Symptom
Motor does not
decelerate in the time
set by the DECEL ramp
and V LIMIT message
appears.
V LIMIT message
appears continuously.
OPT SC message
appears
OC
OV
message appears.
OT message
Motor is unstable.
Excessive Motor
Heating.
Cause
Voltage limit circuit is
operating.
Input voltage has exceeded
maximum rating.
Short circuit on motor
terminals.
Earth Fault on motor
terminals
Motor current was greater
than the MSC-3's maximum
current.
Input voltage has exceeded
maximum ratings.
Motor is overhauling.
Ventilation problem.
Drive is constantly
overloaded.
SLIP COMP is set too high.
FLUX PLUS set too high.
Incorrect motor voltage
selected.
Incorrect motor frequency
selected.
CURRENT LIMIT is set too
low.
Motor is running at low
speeds for long times.
Motor damaged or incorrectly
wired.
Incorrect motor voltage
selected.
Incorrect motor frequency
selected.
IM00120 IM00120
MSC-3 Instruction Manual
Remedy
This is a normal operating mode for the
MSC-3. When the load is being decelerated
too fast, the MSC-3 limits the voltage
regenerated by the motor by extending the
deceleration ramp time. Increase the DECEL
time to make this message disappear.
If faster or controlled deceleration is required
fit a dynamic braking module.
See MSC-3 General Specifications for input
voltage ratings.
Check wiring to motor terminals.
Check wiring to motor terminals.
Check drive and motor current ratings.
See general specification and check the
input is within ratings.
Check input supply for voltage transients. Fix
the external source.
Ensure load cannot overdrive the motor. If
necessary fit dynamic braking.
Ensure operating ambient temperature is
within specification.
Check fans are rotating freely and there is no
build up of dust or debris in blades.
Visually examine the heatsink fins for build
up of dust and debris.
Check the MSC-3 continuous current and
ambient temperature rating.
Check that MOTOR NAMEPLATE RPM
setting is equal to the motor rated speed.
Check that NAMEPLATE CURRENT setting
is equal to the motor nameplate current.
Reduce SLIP COMP setting.
Reduce FLUX PLUS setting.
Enter correct MOTOR VOLTAGE from the
MOTOR menu.
Enter correct MOTOR FREQUENCY from the
MOTOR menu.
Increase CURRENT LIMIT setting.
Do not run the motor heavily loaded at low
speeds for long periods unless the motor has
been suitably de-rated or is force cooled.
Check the motor and motor wiring for faults.
Enter correct MOTOR VOLTAGE from the
MOTOR menu.
Enter correct MOTOR FREQUENCY from the
MOTOR menu.
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