100A 3 pole, 2 way switch

[Chris Styles]

Hi,

My brother is fitting a generator to his house (very rural), and needs to source a 100A 250VAC 3 pole changeover switch...

Any idea where he's likely to find such a thing??

Cheers

Chris

[jim_in_sussex]

Talk to A1 Electrical (an independant unit trading within the TLC umbrella), Tunbridge Wells tel [phone]

You'll get good advice & even if you live nowhere near you still might be able to have it delivered via TLC.

HTH

[Andrew Mawson]

I think the conventional method is a cross connected and mechanically interlocked pair of contactors so arranged that when one is operated the other is electrically and physically prevented from energising. Same system is used for reversing three phase motors.

AWEM

[Sparks]

What power is the generator? You can get one of these, but the generator side is only rated at 40A

think you could just uprate the RCD and cables inside if the generator is bigger, but haven't taken mine apart to look :-)

Sparks...

[Dave Liquorice]

You mean something like this:

[Colin Wilson]

I can`t be sure of the protection required on a generation setup, but IIRC its something like "G58 protection" - although this may only apply to the export of electricity back into the network.

[Ian_m]

friend in New Forest with intermittant electric supply had a generator fitted that supplied just the boiler, fridge/freezer, kitchen lights and single socket for TV/Sky box. Uses a tiny Honda generator.

I think this was done with a feed from CU via a contactor (?) with generertor power to a small CU with a 16A (boiler, socket and fridge) and 6A (lights) radially wired to the items in the house. He was having major building work done at the time so cable running was not an issue. I think the function of the contactor was to isolate the incoming mains and connect the generator power when generator was started. All done by an electrician, I think also some pavement was dug up as well to provide and earth spike/connection. And a battery powered emergency light thing in the generator cupboard (outside) that comes on if the mains fails so that you are a*sing around in the dark trying to get the generator started.

Only needed it once since fitting, 3 years ago, but thats life.....

[Ian Stirling]

I'm planning - at some time in the near future to do a slightly similar thing. UPS connected to small CU near the main CU, plugged into a socket. With assorted 1, 0.5A MCBs.

Ring, with 1,2A round-pin sockets, for small loads (TV, ...) Another, with 10A sockets, for freezers/... On extended power cuts, unplug UPS from mains socket, plug UPS into generator socket, and throw the changeover switch to activate the freezer circuit.