To relocate supply of a c.breaker 11 kV from a common busbar

[SA07]

Hi
We have a series of 11 kV c.breakers all connected next to each other. In future, due to some some changes in operation, our turbo-alternator will generate less kW and it will not be able to island and supply all the loads connected to the 11 kV busbar. We want to disconnect the supply of 1 c.breaker for a load from the 11 kV busbar and connect it with a cable before the tie breaker.By reducing the load on the common busbar, the alternator will be able to island.
We want to keep the c.breaker 11 kV physically at the same place.
Is this possible with ABB c.breaker 11 kV VD4 Unigear?

 

[SolarPrestige]

Your Unigear switchboard has an IAC rating (internal arc containment) to match the IEC standard requirements. This means that flash-overs inside the switchboard in the cable compartment or the CB compartment are safely vented. I can see this in the system you have, ducting installed overhead. Even the busbar compartment can vent to the top, although it is designed to have a very low risk of failure. What you want to do will destroy that rating and make the switchboard unsafe to operators and maintainers.

There is also realistically no room to do what you want to do, or I expect you will do damage to the busbars achieving this change.

I can see reconfiguring your switchgear by adding a bus-coupler to join the incomer to your separated load, while being able to disconnect it from the other loads, would work. But that needs another 2 x panels for a bus-coupler and moving other loads around.

 

[SA07]

Thks SolarPrestige