3 phase supply, advice required

lurch said:

Some advice please. . . I have a local community centre (old prefab) that has a 3 phase TNS supply from the local DNO. I have carried out a EICR which has unsatisfactory on various points, however I am trying to locate the regulation that covers isolation. . . . the scenario is 3 phases in to 3 phase meter, and then 3 separate single phase domestic Consumer units, all located within a cupboard.

My concern is that there is no single point of isolation on the 3 phase supply. I want to give this a C2 but not having come across this scenario before and want to know the regulation that covers this . . . if there is one. Or is it totally acceptable to have this setup as it is. . . . constructive answers always welcome.

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Pete999 said:

You have 3 points of isolation 1 on each Consumers Unit.

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lurch said:

agreed. . . but Ive always had it drummed into me from way back that there should be a single point of isolation in the event of an emergency

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lurch said:

Some advice please. . . I have a local community centre (old prefab) that has a 3 phase TNS supply from the local DNO. I have carried out a EICR which has unsatisfactory on various points, however I am trying to locate the regulation that covers isolation. . . . the scenario is 3 phases in to 3 phase meter, and then 3 separate single phase domestic Consumer units, all located within a cupboard.

My concern is that there is no single point of isolation on the 3 phase supply. I want to give this a C2 but not having come across this scenario before and want to know the regulation that covers this . . . if there is one. Or is it totally acceptable to have this setup as it is. . . . constructive answers always welcome.

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Pete999 said:

You would be extremely unlucky to have an emergency on all SP&N CUs at once Lurch, think the isolation matter is covered. Remember it may be a 3 phase supply, but all you have is 3 SP&N Systems

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Steve Bramah said:

If it was my job, i would fit a 4 pole 100a isolator, much the same as your electrical utilities supplier would fit. Not expensive, and sorts out the "one point of isolation" reg. Hope this helps.

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Pete999 said:

You would be extremely unlucky to have an emergency on all SP&N CUs at once Lurch, think the isolation matter is covered. Remember it may be a 3 phase supply, but all you have is 3 SP&N Systems

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Steve Bramah said:

Hi Pete, I don't think it makes any difference whether its a 3 phase supply or a single phase!
A local plumber in Prestwich,Manchester turned off the comsumer unit, because he was going to change the shower. What he didn't spot was a Wylex 104 in the corner of the mains cupboard. Consequently, the world is one pluber less.

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Steve Bramah said:

Hi Pete, I don't think it makes any difference whether its a 3 phase supply or a single phase!
A local plumber in Prestwich,Manchester turned off the consumer unit, because he was going to change the shower. What he didn't spot was a Wylex 104 in the corner of the mains cupboard. Consequently, the world is one plumber less.

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Pete999 said:

Could happen anywhere switching off the wrong Mains Switch, just an important question, was the Plumber trained in the Safe Isolation Procedure? seems not in this
instance.

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