Earthing Switch; Figure 60: Blocking Conditions Of The Earthing Switch In Pcm600; Figure 61: Single Line Diagram, The Circuit Breaker Is Open And In The Test Position; Figure 62: Single Line Diagram, The Circuit Breaker Is In The Intermediate Position - ABB UniGear Digital Commissioning And Testing Manual

PA N E L I NT ER N A L I NT ER LO C KI NG
5.1.3

Earthing switch

The earthing switch can only be closed if the circuit breaker is in the test position or
the plug is out.
The dedicated protection function for supervision of the earthing operation is ESSXWI or
ESSXSWI.
Relay control access to the shutter of the earthing switch shaft by means of blocking coil RL3.

Figure 60: Blocking conditions of the earthing switch in PCM600

Step 1/7
Move the circuit breaker into the test position and keep it open. Check the circuit breaker sta-
tus on the protection relay LHMI.

Figure 61: Single line diagram, the circuit breaker is open and in the test position

Step 2/7
Move the circuit breaker truck out of the test position about a half turn of the crank. Check
the circuit breaker truck status on the protection relay LHMI.

Figure 62: Single line diagram, the circuit breaker is in the intermediate position

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AP PAR ATU S CO NTR O L T E S TI NG
1 VLG 5000 17 C