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Have I got 3-phase?

Probably a silly question here, as most of you know how electrically dyslexic I am.

Just putting the final touches to the workshop floor repairs etc. and happened to glance up at the distribution board, noticed that the SWA cable coming in goes through a box with a rather large fuse that is labelled "60/80A 415V".

The top of the box has outlets for 4 cables to the distribution board, but obviously only 2 of these plus earth are coming out. As you can get single phase from a 3 phase supply by coming off one live and the neutral, does this mean I may have a 3 -phase supply into the workshop?

Picture here:

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Can you tell anything from this, or would it need opening up and checking by a professional (i.e. not me..)?

Peter

Reply to
Peter Neill
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I'd guess that is a single-phase incoming cable, a three-phase main fuse box would be larger and wider than that, and most are 100A per phase, going back to the early 1980's.

The 415V rating is just that, it is rated for use on 415V but is actually on one leg of the 3-phase street supply.

If it 'is' a 3-phase cable with just one phase used, then you're in business! get a new header box and off you go.

A 3-phase 100A per phase street cable is about 1.25" diameter, more if it an old cable. Single-phase street vfeeders are about 7/8" or so in diameter.

Peter

-- Peter & Rita Forbes Email: snipped-for-privacy@easynet.co.uk Web:

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Reply to
Peter A Forbes

Thanks Peter.

I'm at work now so I can't check, but I'm pretty sure the cable is around 7/8" or so, certainly not as large as 1.25". I guess I was probably being a bit hopeful, but thought it may have solved a few problems or the cost of more inverters/convertors.

Peter

Reply to
Peter Neill

You would have three fuse holes for three phase ;) The second pair of outlets at the top are probably for a feed to second meter for split accommodation.

Reply to
Lester Caine

board,

Peter,

A three phase incommer would look more like this:

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Which was a nice surprise I found in the property we are hoping to buy in East Sussex. Would anyone like to hazzard a guess what size the tails are, as I know from experiance 100 amp fuse carriers don't necessarily have 100 amp fuses in them (having recently blown a 60 amp in my present house )

AWEM

Reply to
Andrew Mawson

They would have 100A fuses, those tails are probably 16mm or maybe 25mm, but be careful, the meter tails are usually double-insulated and look bigger than they are.

Picture of ours is at:

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Note that the electricity board didn't ever colour-code the wires from the main fuses to the meter, and even when the meter was changed a few years ago for an electronic one, they still didn't comment or suggest a change.

Peter

-- Peter A Forbes Prepair Ltd, Luton, UK snipped-for-privacy@easynet.co.uk

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Reply to
Prepair Ltd

hello Peter if you really want proper three phase have a look at how far you are from the middle of the road where the supply comes in if it's a resonable distance it's not that hard or that expensive to have it put in contact the electricity service provider say that you want it for model engineering and get them to give you a quote could be cheaper than converters and inverters on three occasions on moving house I've had this done and it works out alot cheaper cheers Colin

Reply to
Colin Wildgust

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