ABB ACS480 Troubleshooting Manual page 10

Code
Warning / Aux. code
(hex)
A793 BR excess
temperature
A794 BR data
0000 0001 Resistance value too low.
0000 0002 Thermal time constant not
0000 0003 Maximum continuous power
A79C BC IGBT excess
temperature
A7A2 Mechanical brake
opening failed
A7AB Extension I/O
configuration failure
Cause
Brake resistor temperature has
exceeded warning limit defined
by parameter 43.12 Brake
resistor warning limit.
Brake resistor data has not
been given.
given.
not given.
Brake chopper IGBT
temperature has exceeded
internal warning limit.
Status of mechanical brake
acknowledgement is not as
expected during brake open.
I/O module is not connected to
the device or parameterization
conflict with connected I/O
module.
Fault tracing 09
What to do
Stop drive. Let resistor cool down.
Check resistor overload protection
function settings (parameter group
Brake chopper).
Check warning limit setting, parameter
43.12 Brake resistor warning
Check that the resistor has been
dimensioned correctly.
Check that braking cycle meets allowed
limits.
One or more of the resistor data settings
(parameters 43.08...43.10) is incorrect.
The parameter is specified by the
auxiliary code.
Check value of 43.10.
Check value of 43.08.
Check value of 43.09.
Let chopper cool down.
Check for excessive ambient
temperature.
Check for cooling fan failure.
Check for obstructions in the air flow.
Check the dimensioning and cooling of
the cabinet.
Check resistor overload protection
function settings (parameters
43.06...43.10).
Check minimum allowed resistor value
for the chopper being used.
Check that braking cycle meets allowed
limits.
Check that drive supply AC voltage is not
excessive.
Check mechanical brake connection.
Check mechanical brake settings in
parameter group 44 Mechanical brake
control.
Check that acknowledgement signal
matches the actual status of brake.
Check that the I/O module is connected
to the device.
Check that no parameters are connected
to non-existing I/O parameters.
43
limit.