Replacement hob wires too large

[Whingell]

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Hello, we have just had a replacement hob through warranty, the electrician who came to fit it said it needs ho5rrf cable when we have 6mm. He wants to replace the entire cables. My house was only rewired 3 years ago. Does this sound ok, or would it be cheaper to buy adifferent hob that accepts the 6 mm..
Theres also confusion over wether its a induction or ceramic, from what i can remember the original electrian said we needed 10mm for induction so we bought ceramic.

Thanks in advance for any advice

 

[Dartlec]

I take it you mean the 6mm in place is 6mm Twin and Earth and the electrician wants H05-RR-F flex instead?

There is no specific reason why twin and earth can't be connected into a hob, it is very commonly done. The manufacturer will usually specify flex purely because it is the best choice - but that doesn't mean than a sensible electrician can't decide alternatives are also safe.

Is there a cooker connection unit or similar junction box local to the hob as is commonly done? If so flex could be used for the last part to the hob, without replacing the main run of cable.

The size of the cable needed will be down to the rating of the new hob, the protective device at the consumer unit, and the method of installation.

If the hob is being replaced through warranty, then I would expect them to replace with something of the same rating, or cover the installation changes required for what they have supplied.

Do you know the rating of the new hob? What size breaker is protecting the circuit that feeds the hob?

 

[brianmoooore]

The only HO5 cable you'll need is a metre or so length from a conveniently sited cooker connection plate to the hob.
This is a common problem with modern cooking appliances that are designed for use with the 3 phase supplies used in most European countries, then 'modified' for the UK by including a couple of copper links with them.
The required cable size for 3 phase would probably be 1.5mm2, so this is what the connector boxes are designed to accommodate, rather than the 6mm2 required for single phase.
I doubt if the induction hob would require 10mm2 - there's a thing called diversity to apply to the calculations.

 

[Whingell]

The only HO5 cable you'll need is a metre or so length from a conveniently sited cooker connection plate to the hob.
This is a common problem with modern cooking appliances that are designed for use with the 3 phase supplies used in most European countries, then 'modified' for the UK by including a couple of copper links with them.
The required cable size for 3 phase would probably be 1.5mm2, so this is what the connector boxes are designed to accommodate, rather than the 6mm2 required for single phase.
I doubt if the induction hob would require 10mm2 - there's a thing called diversity to apply to the calculations.

Ok. Thank you. Much appreciated