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[bazinthenorth]

I wish to transfer one lighting circuit and the central heating circuit (both < 5 amp) from the consumer unit to the generator. I require one 4 pole or two 2 pole changeover switch(es) with centre off (certainly break before make), but cannot find a suitable manufacturer/supplier. Does anyone know of such a switch(es)?

[ericmark]

There are change over switches but can't use links with this forum. I would use a plug and socket arrangement as that allows one to change the generator.
Normally the change over is arranged so it can't be done too quick. Fridge, freezers etc often need 3 mins for pressure to drop before reconnection and the unplugging and plugging in ensures the change over is not too fast.

[bazinthenorth]

[quote="ericmark"]There are change over switches but can't use links with this forum. I would use a plug and socket arrangement as that allows one to change the generator.
Normally the change over is arranged so it can't be done too quick. Fridge, freezers etc often need 3 mins for pressure to drop before reconnection and the unplugging and plugging in ensures the change over is not too fast.[/quote]
I do not need a weblink. A description sufficient for me to do a seach is enough. I understand what you say re plug and sockets but a switch is my ideal solution.Thanks for your interest.

[ericmark]

I did google "generator change over switch" and I got everything from a 32A change over switch from TLC "KM T338212I 32 Amp 3 Pole Change Over Switch - IP65" at £36.15 to a special.
One consideration that must be made is that with power failure one can't rely on any earth provided by supplier so earth rods will likely need fitting.

The problem is with a single item a good example is a shaver you can supply this from an isolated supply and to get a shock even without any earth protection it need two independent faults so is relatively safe which is whole idea of shaver socket.

However once you use multi-items the chance of a fault on two items combining to cause a shock becomes a real danger and the method to safeguard from this is the earth system.

The Earth and Neutral are normally not switched but with power failures which are normally caused by faults one could easy end up feeding dangerous voltages back down the earth and/or neutral and injuring electricians working on the supply.

Hence why I would normally use plug and socket unless going whole hog and installing something sold for the job as seen here. Google "justgenerators.co.uk/pages/powertransfer.htm"
I hope the link is left in. These are expensive and likely very little different than the cheaper switch from TLC but if it goes wrong and one ends up in court one can show you did all you could to ensure it was safe.

The same applies to getting an enclosure and fitting isolators and MCB's and RCD's to buying a consumer unit. Both likely will do the same job but if it goes wrong then buying the consumer unit is unlikely to require you to appear in court and explain why you did things that way.

And sorry to say I have seen things go wrong. One case was a fire involving a small generator where the generator could be changed from 110v to 230v at flick of a switch but unknown to guy using generator in 230v mode earth was connected to 55v different tapping than neutral so when there was a fault since no fuses on neutral it caused a fire. Not really something one tests for unless you have been warned and so I would be very wary of the switched change over system.