Electrical Question

Cable for a electric shower

hi can you tell if a 10mm electric cable is suitable for a 9.5kw shower please/ thanks

3 Answers

Best Answer

To be able to confirm its suitability 100% the length of cable also needs to be factored into the caclucaltion. But in simple terms 10,000 watts divided by the supply voltage of 230volts = 43.47amps

As 10mm cable installed to reference Method A (i.e. enclosed in a conduit and buried in the wall below plaster level) is 46amps, a 10mm cable is fine. But the volt drop for a long run say over 12m would need to be considered.

Remember if you are planning on installing the shower cable yourself you will need building regulation approval from your local authority as it is notifiable works under part P of the building regulations.

Answered 9th Jan 2013

Electrical Safety Services

Member since 17 Oct 2011

For standard domestic installation 10mm cable is fine but get a qualified Electrician to carry out the job

Answered 11th Jan 2013

CIVIL Electrical Services

Member since 2 Nov 2008

As others have stated here, it does depend on how the cable is routed and the distance of the circuit in question.

Hopefully you’re buying the cable for an Electrician to install and I’m not helping a DIY enthusiast break the law here.

This needs to be certified, as I guess you probably already know. A Bathroom is a special location.

The certificate is not just a piece of paper, it’s a statement that the circuit has been installed and tested correctly, along with other parts of the Installation. It will also show that the circuit will disconnect in the required time (ms) in the event of a fault.

If the load is 9.5kw and the reference method was B, then 10mm PVC PVC Twin and Earth cable would be OK up to about 40mtrs. The voltage drop would be 3% (7.1 Volts) and the total load is just under 40amps.

In most Domestic circumstances, the consumer unit is never this far away from the shower being installed, so 10mm is adequate providing it’s routed correctly, mechanically protected if exposed and in the correct zones.

Hope this helps you.
GPS Electrical

Answered 12th Jan 2013


Member since 16 Oct 2012

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