De-Energize

[Alwayslearningelec]

Hello. So have to replace the 100A disconnect switch tied into the last cubicle of this switchboard. Assume right way to do it is to shutdown this board.

Looks like drawout breakers feeding this board.....actually looks like a few breakers feeding this board, not sure how that could be.

 

[infinity]

Part of your drawing is truncated can you give us a brief explanation as what we're looking at?

 

[ModbusMan]

I would expect to see some kind of kirk key or other interlock mechanism higher up on the drawing. From the portion provided, there are potentially eight breakers and (at least) four different upstream panels all paralleled as inputs to that bus with no cross- or back-feed prevention.

 

[Alwayslearningelec]

 

[ModbusMan]

Assume right way to do it is to shutdown this board.

Looks like it... the added detail, to me, appears to be a combination of on-site solar- and fuel cell-based generation, together with redundant parallel feeds off the (probably diesel) generator, all three of which likely have a central paralleling controller. Odd that they'd do all that work to ensure the thing never loses power, only to still be forced into shutting the whole thing down to replace a disconnect. If you're able, I'd ask if they have disconnects on the sections that aren't marked here, just to be sure there isn't a way to isolate the cubicle you're working in from the rest of the bus.

 

[don_resqcapt19]

The line side of that disconnect is connected to the conductors on the line side of the service disconnect. The service will have to be disconnected by the utility to do that work.