ACS 300 User’s Manual 75
Chapter 8 - Fault Tracing
Table 8-1 Fault tracing.
Fault indication Possible cause Remedy
(1) NO FAULT This message only appears in
the fault memory.
(2) OVERVOLTAGE DC bus voltage has exceeded
130 % nominal voltage. Over-
voltage is generally caused
when the motor runs as a gen-
erator in drives where the load
inertia is high and the decelera-
tion time is set low. Too high
supply voltage may also be the
cause.
• In case of temporary supply
voltage peak, reset and start.
• Use longer deceleration time
or
• Use coasting stop function if it
is compatible with the applica-
tion.
• If short deceleration time is
needed, use external Braking
options.
• Check supply voltage (400 V)
(3) UNDERVOLTAGE DC bus voltage has gone
below 65 % of the nominal volt-
age. Most common reason for
low voltage trip is failure in the
AC line supply, loss of phase or
“brown out” condition.
• In case of temporary supply
voltage drop, reset and start.
• Check AC line input.
(4) OVERCURRENT Motor may be too small for the
application.
Motor current is too high due to
• high load inertia/short ramp
times
• sudden load torque change
• stalling motor
• motor wiring or motor failure
• long motor cable
• Check ramp times
• Remove mechanical problem
causing increased load torque.
• Check cables and motor
• Use optional output chokes
• Check dimensioning, use
larger ACS 300 and motor if
necessary.
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