Alarms, faults and system messages
9.4 Faults
The fault buffer can accept up to eight actual faults. The next to last fault is overwritten if an
additional fault occurs after the eighth fault.
Figure 9-7
Fault acknowledgement
In most cases, you have the following options to acknowledge a fault:
● Switch the inverter off and then on again
● (switch off the main power supply and the external 24 V supply for the Control Unit and
● Press the acknowledgement button on the operator panel
● Acknowledgement signal at digital input 2
● Acknowledgement signal in bit 7 of control word 1 (r0054) for Control Units with fieldbus
Faults that are triggered by monitoring of hardware and firmware inside the inverter can only
be acknowledged by switching off and on again. You will find a note about this restricted
option to acknowledge faults in the fault list of the List Manual.
252
Complete fault buffer
switch it on again).
interface
Inverter with CU240B-2 and CU240E-2 Control Units
Operating Instructions, 07/2010, FW 4.3.2, A5E02299792B AA