Shower Earth Cable

[weeman750]

I am going to fit a new electric shower, 8.5 or 9kw, not bought it yet. I am going to use 10mm T&E cable. Do I have to use 10mm earth cable as well or would 6mm earth cable be ok.

 

[RF Lighting]

What is this earth cable for?

Do you mean the supplimentary bonding conductor? (to connect all the extraneous parts in the bathroom)

 

[Spark123]

The twin and earth cable has an earth core in it, you don't generally need to run another one to the shower. It is also advisable to fit an RCD to the shower supply.
You do however need to make sure your main and supplementary bonding are both up to scratch:
//wiki.diynot.com/electrics:main_equipotential_bonding
//wiki.diynot.com/electrics:sp...l_bonding:supplementary_equipotential_bonding

beaten by RF lol

 

[weeman750]

The earth cable would just be for the shower. The earth on the 10mm T&E cable is not the same size as the live & neutral cores. The rest of the bathroom is already bonded.

 

[RF Lighting]

The earth in the T&E cable is sufficient without any addition.

This is because the 10.0mm² conductors will be carrying the 40A+ which your shower requires for a sustained period.

The earth will only carry a current in the event of a fault, and at the worst the fault will clear in a maximum of 5 seconds, (although is usually far quicker than this) so a smaller CPC (earth) is sufficient.

 

[weeman750]

Thanks for the info. I will be fitting an RCD .

 

[securespark]

Another throwback to olden times!

I know not quite why, but in the 70's and 80's (and obviously still today!) it was often found that a 6/10mm² earth would be run in along with the t&e for the shower.

 

[weeman750]

I am a qualified electrician but have not worked at my trade for quite a few years, hence "Another throwback to olden times!"