7EN02-0423-00

Example: injection exclusion with three incoming feeders

You can use injection exclusion to monitor three incoming feeders.

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

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

The device priority is as follows:

  • Device no.1 is the device with the highest priority 1: it always injects into the system if D1 is closed or open.

  • Device no.2 is the device with priority 2: it always injects into the system except when there is a closed path between the device and one device with a higher priority, in this case device no.1. Therefore, device no.2 is inhibited when D2 and D1 are closed.

    Device no.2 injection inhibition = D1AND D2

    To implement this logic, wire the injection inhibition of device no.2 to the 2 auxiliary contacts of D1 and D2.

  • Device no.3 is the device with priority 3: it always injects into the system except when there is a closed path between the device and one device with a higher priority, in this case device no.1 or device no.2. Therefore, device no.2 is inhibited when D3 and D2 are closed, or D3 and D1 are closed.

    Device no.3 injection inhibition = (D3 AND D1) OR (D3 AND D2) = D3 AND (D1 OR D2)

    To implement this logic, wire the injection inhibition of device no.3 to the auxiliary contacts of D1, D2 and D3.

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