9
Service
Motor malfunctions
Operating Instructions – Explosion-Protected MOVI-SWITCH
®
Drives
43
Fault
Possible cause
Measure
Severe speed loss un-
der load
Motor overload
Measure power, check project planning and
use larger motor or reduce load if necessary
Voltage drops
Check cross section of supply cable, replace
with cable of larger cross section if necessary
Motor heats up exces-
sively (measure tem-
perature)
Overload
Measure power, check project planning and
use larger motor or reduce load if necessary
Insufficient cooling
Provide for cooling air supply or clear cooling
air passages, retrofit forced cooling fan if ne-
cessary. Check the air filter, clean or replace if
necessary
Ambient temperature too high
Observe the permitted temperature range, re-
duce the load if necessary
Motor in delta connection instead
of star connection as intended
Correct the wiring, observe the wiring diagram
Loose contact in supply cable (one
phase missing)
Tighten loose contact, check connections, ob-
serve wiring diagram
Fuse blown
Look for and rectify cause; replace fuse
Line voltage deviates from the
rated motor voltage by more than
5% (range A) / 10% (range B).
Adjust motor to line voltage
Nominal duty cycle (S1 to S10,
DIN 57530) exceeded, e.g. caused
by excessive starting frequency
Adjust the nominal duty cycle of the motor to
the required operating conditions; consult a
professional to determine the proper drive, if
necessary
Excessively loud
Ball bearing compressed, dirty or
damaged
Re-align motor and the driven machine, in-
spect rolling bearing and replace if necessary.
Vibration of rotating parts
Look for the case, possibly an imbalance; cor-
rect the cause, observe method for balancing
Foreign bodies in cooling air ducts Clean cooling air ducts
25988670/EN – 04/2020
