4 pole 160 / 200a isolator

Has anyone a 4 pole (ie 3 phase with switched neutral) isolator / switch disconnector / switch fuse with a rating of 160a - 200a or greater kicking arround that they'd like to convert to folding money? I'm having a somewhat larger than normal 3 phase supply installed and would like it's first point of calling to be an isolator - being 'TT' it needs to be four pole.

AWEM

Reply to
Andrew Mawson
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What is 'TT' ?? and why do you need to break the Neutral, which should be tied to ground anyway?

Peter

-- Peter A Forbes Prepair Ltd, Rushden, UK snipped-for-privacy@prepair.co.uk

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Reply to
Peter A Forbes

money?

should be tied

Overhead supply - ground is by earth electrode, EDF do not guarantee neutral will stay near earth despite the fact I can see the main bond between neutral and earth on the transformer on my land 20 yds from where the supply will terminate ! With TT supplies Neutral has to be treated like a live conductor.

See:

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AWEM

Reply to
Andrew Mawson

TT is a supply where the supplier does not provide an earth.Earthing on the customer premises is by ground rod.Neutral must never be tied to earth in these circumstances. I did not know there was a requirement to switch the neutral and would be very surprised if the board is asking for that,but wait to be corrected. I think there is also a requirement for an RCD on the incomer. TT is quite common in rural situations. Mark.

Mark.

Reply to
mark

snipped-for-privacy@prepair.co.ukhttp://www.prepair.co.ukhttp://www.prepair.eu>

Correct - there is no EDF requirement to switch any of the incoming cables, but for testing purposes on a TT system Neutral has to be treated as a potentially live conductor so must be isolated. Also correct that an RCD is required - 100mA trip on the whole system, and the 30mA type on all sockets.

AWEM

ps anyone got an isolator???????

Reply to
Andrew Mawson

Andrew,all three phase isolators have a detachable link on the neutral terminal block for testing purposes. Mark.

Reply to
mark

You`ve probably seen this.I`ve bought from this guy and he`s sound.

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Reply to
mark

Haven't got one you can have, but if you can put up with new then you can use one of these:-

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Never had any problems with these folk.

The other thing to do is to just ask the frogs to fit an isolator when they install the supply. Worked for me when I got my meter changed (not by edf and not three phase though...)

Mark Rand RTFM

Reply to
Mark Rand

There is a requirement in the wiring regs requiring that all circuit conductors can be disconnected from the supply by a "linked switch". ie phase(s) and neutral, but there's an easement such that if one conductor is effectively earthed, the you need only switch the live conductor(s) and provide a bolted neutral isolating link. Dunno where it is in the madness that passes for the regs these days, but it's A2 in the 14th edition.

Regards,

David P.

Reply to
David Powell

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