KEB COMBIVERT F5, Operation Manual, Page: 96 / 138

96
Drive Faults
Error/Message Alt. /
(NUM)
Description Cause/Solution/Troubleshoot
Error Over Cur-
rent EOC
(4)
Occurs when the
specified peak
output current is
exceeded or if
there is a ground
fault. The current and peak current may be viewed in Diagnos-
tic Screen #1 or DG06 and DG31. To reset the logged
peak value, press the F4 Reset key from the Diagnostic
Screen.
Causes for over current errors:
If the error occurs instantly at the start of each run, the
issue may be:
Ground fault on motor leads.
Damaged or slow to close motor contactor.
Shorted output transistor.
Motor failure.
If the error is intermittent, the issue may be due to:
Damaged or slow to close motor contactor.
Loose motor connections.
Electrical noise, faulty grounding.
To determine if the over current is caused by the inverter,
motor, or intermediate component (e.g. motor contactor),
systematically remove these items from the system.
Start by bypassing the motor contactor (do not simply
jumper!).
Checking of the motor and motor cables for short cir-
cuits or opens:
Resistance checks should be done with the motor
disconnected from the inverter. With the motor cable
disconnected from the inverter, make a resistance
check from phase to phase. This should read the
winding resistance, as specified by the motor manu-
facturer. Phase to ground resistance should read
an open circuit. If measurements indicate a fault,
disconnect cables at motor side and remake the test
to determine if the fault is with the motor or cabling.
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