Extension of main switchboard or Distribution board?

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Dan L
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Extension of main switchboard or Distribution board?

Post by Dan L »

It's not uncommon to see a main switchboard made up of seperate enclosures and bars etc mounted next to each other. (usually old)


Can you have an enclosure a meter away or 2 meters away from msb will it still be an extension of main switchboard or will it then have to be a DB.

if its supplied from installation wiring as apposed to switchboard wiring due to distance or it it simply if its supplied from the main switch or a sub circuits that defies it.

Ideally it would be one board or at least hard up against each other but technically what is the cut off point?

Thanks in advance
AlecK
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Re: Extension of main switchboard or Distribution board?

Post by AlecK »

Based on definition of 'switchboard" [1.4.91]; If the enclosures aren't touching it isn't the same "assembly" .
Which would make the second one a DB

But there's very little difference in requirements between MSB & DB;
Main switches have to be at MSB (unless for alternative supply).
Each assembly has to have its own N&E bars for the circuits it supplies, can't use a common set.
and the supply (submains) to a DB has to include a PEC (unless in an outbuilding)
Dan L
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Re: Extension of main switchboard or Distribution board?

Post by Dan L »

I read that definition many times and never picked up on that.

Makes sense though, thanks.
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