Tripping Of The Circuit-Breaker In Case Of Undervoltage; Fault And System Messages; Diagnostics Via Leds; Leds Of The Power Stack Adapters - Siemens SINAMICS SM120 Operating Instructions & Installation Instructions

8.2.1.1

Tripping of the circuit-breaker in case of undervoltage

If a serious fault occurs (e.g. overload in the DC link), the drive is immediately disconnected
from the power supply by means of the safety shutdown function.
Residual voltages
This function cannot ensure that the drive stops immediately, nor can it ensure that residual
voltages do not still exist at the output terminals and within the unit.
High voltages can cause death or serious injury if the safety rules are not observed or if the
equipment is handled incorrectly.
Always carefully observe the "five safety rules (Page 13)".
The shutdown of the circuit-breaker is triggered by a safety contactor combination.
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.
8.3

Fault and system messages

8.3.1

Diagnostics via LEDs

8.3.1.1

LEDs of the Power Stack Adapters

Table 8-1 LEDs of the Power Stack Adapters
LED Color
PWR -
Red
Green
SINAMICS SM120 6SL38855?B
Operating Instructions 12/2015
WARNING
Status Description; cause
Off 24 V power supply has failed or is too low
(< 14 V) or internal fuse defective.
Continuous 24 V power supply is available (>14 V);
light internal board voltage fault.
Continuous 24 V power supply OK.
light
Internal board voltages OK.
8.3 Fault and system messages
Remedy
Check input voltage.
If input voltage is > 18 V and LED off:
Return component for repair.
Check input voltage.
If input voltage is > 18 V and LED red:
Return component for repair.
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Operation
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