
338 Fault tracing
A784
Motor disconnect
All three output phases are
disconnected from motor.
Check if parameter
enables the
use of a motor disconnect switch. If not,
check the following:
• All switches between drive and motor
are closed.
• All cables between drive and motor
are connected and secured.
If no issue was detected and drive output
was actually connected to motor, contact
ABB.
A780
Motor stall
Programmable warning:
Motor is operating in stall
region because of e.g.
excessive load or insufficient
motor power.
Check motor load and drive ratings.
Check fault function parameters.
A791
Brake resistor
Brake resistor broken or not
connected.
Check that a brake resistor has been
connected.
Check the condition of the brake resistor.
A7CE EFB comm loss
Programmable warning:
Communication break in
embedded fieldbus (EFB)
communication.
Check the status of the fieldbus master
(online/offline/error etc.).
Check cable connections to the EIA-485
terminals 25, 26, 27 and 28 on the
control unit.
A7EE Panel loss
Programmable warning:
Control panel or PC tool
selected as active control
location for drive has ceased
communicating.
Check PC tool or control panel
connection.
Check control panel connector.
Check mounting platform if being used.
Disconnect and reconnect the control
panel.
A71C
I/O Module internal
error
Calibration data is not stored in
the IO module. Analog signals
are not working with full
accuracy.
Replace drive.
A8A0
AI supervision
Programmable warning:
An analog signal is outside the
limits specified for the analog
input.
Check signal level at the analog input.
Check the wiring connected to the input.
Check the minimum and maximum limits
of the input in parameter group
.
A8A1
RO life warning
The relay has changed states
more than the recommended
number of times.
Change the control board or stop using
the relay output.
0001 Relay output 1
Change the control board or stop using
relay output 1.
A8A2
RO toggle warning
The relay output is changing
states faster than
recommended, eg. if a fast
changing frequency signal is
connected to it. The relay
lifetime will be exceeded
shortly.
Replace the signal connected to the relay
output source with a less frequently
changing signal.
0001 Relay output 1
Select a different signal with parameter
.
Code
(hex)
Warning / Aux. code
Cause
What to do
ACS180 FW.book Page 338 Tuesday, March 9, 2021 2:25 PM