10mm t&e submain cpc

[JakeF]

I know there’s the adiabatic equation to work earth size but generally if you install a twin and earth cable for distribution, do you need to worry about the smaller cpc size

My situation is 20 metre 10mm t and e run and not using it to provide earth bonding. Will the 4mm cpc be adequate. 50A mcb not many circuits to feed.

 

[telectrix]

what's the earthing arrangement?

 

[Risteard]

not using it to provide earth bonding.

Can you clarify what you mean by this? Earthing and bonding are completely different things, and "earth bonding" does not exist.

 

[JakeF]

what's the earthing arrangement?

Tncs

 

[JakeF]

Can you clarify what you mean by this? Earthing and bonding are completely different things, and "earth bonding" does not exist.

Will the 4mm in the t and e suffice.

Won’t be used for water and gas bond

 

[Risteard]

So it's just being used as a cpc then?

Apply the adiabatic calculation to verify its adequacy then.

 

[Pete999]

Show your calculations Jake.

 

[Strima]

What's the Ze at source of circuit?

Type/rating of OCPD etc?

Installation method?

 

[davesparks]

I know there’s the adiabatic equation to work earth size but generally if you install a twin and earth cable for distribution, do you need to worry about the smaller cpc size

Yes you do need to worry about it, whether it be a final or distribution circuit.

 

[Deleted member 26818]

The term ‘sub main’ suggests a distribution circuit.

 

[davesparks]

The term ‘sub main’ suggests a distribution circuit.

Yes I saw that, my point was that the same consideration needs to be given to both types of circuit.

 

[Taylortwocities]

20metre run of 10mm T&E?
is this an inside or outdoor run?

 

[buzzlightyear]

sub mains to and from would be help full .