3 phase distribution board

[Jako13!]

I’ve got an old DB at work that I’ve had a look at and can see they’ve used the main earth into it and tied it to the neutral connection at the board is this correct?

 

[pc1966]

Today - very much a no as that is TN-C within the installation which is no prohibited by the regulations (not sure if just BBB or under the ESQCR).

But I believe historically there are some TN-C installations from long ago, hopefully others on this forum know a lot more about that than me!

 

[davesparks]

Not normally correct for a standard DB, you may find this on big industrial type switchboards with a TNS incomer (often with a private transformer not a DNO supply)

Can you post some pictures and more details please?

 

[Lucien Nunes]

Or might be correct when fed from a generator. Pics and/or some more context would be helpful.

 

[pc1966]

Good points there - had not though of a private supply arrangement!

 

[Jako13!]

Thanks guys I shall get a picture it is of a private supply!

 

[Jako13!]

Pictures of DB

 

[Lucien Nunes]

And the source of energy is?

 

[Jako13!]

I coul

And the source of energy is?

I’m struggling to find the supply but think I’ve found the isolator which the armoured runs too.