ACS 300 User’s Manual 79
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. Overvolt-
age is generally caused when the
motor runs as a generator in
drives where the load inertia is
high and the deceleration time is
set low. Too high mains 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 voltage. Most
common reason for low voltage
trip is failure in the mains supply,
loss of phase or “brown out” con-
dition.
• In case of temporary supply
voltage drop, reset and start.
• Check mains 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 cabling 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.
(5) LOW AI-SIGNAL Analogue input less than 2 V/4mA
and minimum has been set to
2 V/4 mA or Analogue Input less
than selected “customised
minimum”.
• Input reference has failed or
control cable is broken. Check
the reference circuit.