3 phase supply, advice required

[lurch]

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.

 

[Ian1981]

Since when is it any business of the NICEIC what the regs state? Its either compliant or its not, yet they make a comment that neither confirms it or isnt. Yet people still fall over themselves for these scams.

Am not a QS so was not present during the inspection, this was just feed back from my supervisor.
It’s always stuck in the back of my mind tho.

 

[lurch]

Not a bad idea Steve, but if you relyon the Isolator you mention as the single point of isolation, problem occurs in one particular SP system, then you would isolate all three CUs. Just a thought.

. . . this is the case on any 3 phase installation with a TPN board

 

[lurch]

Not a bad idea Steve, but if you relyon the Isolator you mention as the single point of isolation, problem occurs in one particular SP system, then you would isolate all three CUs. Just a thought.

. . . this is the case on any 3 phase installation with a TPN board

 

[lurch]

Each consumer unit has a means of isolation to their respective circuits.
I can’t see how not having a single point of isolation may result in potential danger to the user of the installation of anyone else.

. . . picture this scenario. Fault on circuit 1 on DB 1. "quick isolate that circuit Dave!" Dave goes to cupboard and isolates first main switch he sees. "Done" . . . but is it??

 

[lurch]

As above, 'joe public' should not be messing with the boards.

I would not hesitate in asking a customer who has rung me to report a smell of burning to go to mains and isolate a main switch until I can get there. This is hardly messing with a board !!!

 

[Dillb]

. . . picture this scenario. Fault on circuit 1 on DB 1. "quick isolate that circuit Dave!" Dave goes to cupboard and isolates first main switch he sees. "Done" . . . but is it??

I would be asking why “Dave” didn’t ask which board in this instance.

 

[Spoon]

I would not hesitate in asking a customer who has rung me to report a smell of burning to go to mains and isolate a main switch until I can get there. This is hardly messing with a board !!!

But if they don't know what they are doing and which board to isolate then maybe you should be telling them to isolate all 3.

 

[Pete999]

I would not hesitate in asking a customer who has rung me to report a smell of burning to go to mains and isolate a main switch until I can get there. This is hardly messing with a board !!!

What's wrong with the Main Switch on the Consumers Unit? Not messing with a Board? but you will be messing with other peoples supply of electricity wouldn't you??

 

[Pete999]

. . . this is the case on any 3 phase installation with a TPN board

Not every TP&N board is supplying 3 SP&N different dwellings.

 

[Pete999]

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.

What for?

 

[Pete999]

Exactam

I would be asking why “Dave” didn’t ask which board in this instance.

Exactamundo, Dave goes to the Cupboard, switches OFF the TP&N isolator, Mrs Brown in the flat in question knows the juice is going OFF Mrs Smith and Mrs Jones in the other two flats call out an Electrician to find out the problem, because their Electric is no more, ergo confusion rules OK?