Example: injection exclusion with two incoming feeders and one coupling

You can use exclusion injection and a coupling to monitor two incoming feeders.

Use of circuit breakers with normally open (NO) auxiliary contacts:

Use of circuit breakers with normally closed (NC) auxiliary contacts:

If	Then
The coupling is closed	The same applies as in the example for injection exclusion with two incoming feeders. See Example: injection exclusion with two incoming feeders for example of injection exclusion with two incoming feeders.
The coupling is open: D1 is closed AND D2 is closed	Both devices are active: Device no.1 monitors the insulation of system 1, Device no.2 monitors the insulation of system 2.

Then

The coupling is closed

The same applies as in the example for injection exclusion with two incoming feeders. See Example: injection exclusion with two incoming feeders for example of injection exclusion with two incoming feeders.

The coupling is open:

Both devices are active:

Device no.2 must be inhibited when the following three conditions are met: