8.3 Fault and system messages
The plant-side circuit-breaker must be equipped with an undervoltage trip to ensure the wire-
break protection for the circuit-breaker OFF command. If a circuit-breaker OFF command is
issued as a result of an overvoltage trip, the circuit-breaker is switched off so that it is fail-safe.
Fault and system messages
Indicating and rectifying faults
The drive provides many protection functions. These protection functions protect the drive
against damage in a fault situation. A distinction is made between the following messages:
The drive indicates a fault by displaying the corresponding fault and/or alarm on the operator
Faults are displayed as follows:
● By illuminating the red LED "FAULT"
● With a permanently jumped to fault mask on the display
Press the <F1> "Help " key function to call up information about the cause and remedial
measures. Press the <F5> "Quitt." key to acknowledge a stored fault.
Alarms are indicated as follows:
● The yellow LED "Alarm" flashes
Every fault and alarm is entered in the fault/alarm buffer along with time the fault occurred.
The time stamp refers to the relative system time in milliseconds (r0969).
A fault is a message from the drive indicating a fault or other exceptional (unwanted) state.
The cause can be a fault in the drive itself or also an external fault. This fault, for example,
could have been issued by the winding temperature monitoring of the asynchronous motor.
The faults are displayed and can be reported to a higher-level control system. Once you
have eliminated the cause of the fault, you must acknowledge the fault message.
An alarm is the response to a fault condition identified by the drive, that does not result in
the drive being shutdown. Alarms acknowledge themselves. If the cause is no longer
present, the alarms reset themselves automatically.
Additionally, a note relating to the cause of the alarm is displayed in the status bar of the
SINAMICS SM120 6SL38715
Operating Instructions 07/2015