Figure 52: Single Line Diagram, The Earthing Switch Shutter Is Open; Figure 53: Single Line Diagram, The Earthing Switch Shutter Is Closed - ABB UniGear Digital Commissioning And Testing Manual

AP PAR ATU S CO NTR O L T E S TI NG
Step 2/6
Insert the earthing switch crank on the shaft. Check the status on the protection relay LHMI.

Figure 52: Single line diagram, the earthing switch shutter is open

Step 3/6
Check that the circuit breaker cannot be moved into service position when the earthing
switch crank is inserted.
Step 4/6
Remove the earthing switch crank from the shaft. The shutter must be closed. Check the
earthing switch status on the protection relay LHMI.

Figure 53: Single line diagram, the earthing switch shutter is closed

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