induction hob wiring

[dapex]

Hey all.. I am having an induction hob installed instead of my current gas hob.. Currently I have my cooker power switch approx 4m from my fuse box (6mm cabling to a 32Amp breaker) . This then has 6mm cabling to a single power socket that my oven is plugged into.. I had presumed that when i get a sparky round he would change the single power socket to a cooker switch with socket and wire the hob in...

BUT he is adamant I need a whole new 6mm cable to the new hob... The hob is 7.4KW and the oven is rated at 2.1 KW...

The question is... is he trying to get one over on me and charge me for work that really isnt needed, or he is correct in his statement.. Reading various places it appears most people say its fine to run them both on the same 6mm because of diversity (although i gather diversity is about not all the hob rings and oven being in use at the same time... but what happens that one time on xmas when they are?

If it matters the house is 18 years old, and the wiring hasnt been touched since the house was built.

Cheers all

 

[securespark]

Ask him why he needs to install a whole new circuit and which regulations apply.
Then watch him climb back on his horse and trot away.

 

[winston1]

but what happens that one time on xmas when they are?

Everything carries on working as normal as the oven and hobs cycle on and off under their thermostats.

 

[ericmark]

As said diversity covers it. Look at it this way, in the old days 32A would feed a stand alone cooker without a problem, today we have more efficient appliances meaning they use less energy, so if 32A did do it now we should get away with less say a 25A supply.

Point is of course if you switch on everything together then for a short time it can use more, although once the devices start to cycle on/off they will use less, however even with that initial switch on the worse case scenario is it trips the MCB, so no real harm done.

So both on one double cooker connection unit is OK, that's why they make double cooker connection units.

 

[ban-all-sheds]

is he trying to get one over on me and charge me for work that really isnt needed, or he is correct in his statement..

Yes, yes, and no.

Ask him why he needs to install a whole new circuit and which regulations apply.

If you do, please let us know what he says.

 

[JohnW2]

As said diversity covers it. Look at it this way, in the old days 32A would feed a stand alone cooker without a problem, today we have more efficient appliances meaning they use less energy, so if 32A did do it now we should get away with less say a 25A supply.

Indeed - and many modern cookers would probably be fine on a 16A circuit, since that can support a cooker with a pre-diversity power of about 6.9 kW.

Kind Regards, John

 

[dapex]

Cheers for the helpful replies.. I will get someone else round for another quote.

Cheers

 

[ban-all-sheds]

Ask him why he needs to install a whole new circuit and which regulations apply.

Dapex - did you ask him?

 

[dapex]

Dapex - did you ask him?

when i rang him, he says he suddenly realised he may not need to fit a new circuit

Went with someone else to be honest... next guy i rang openly said it should be fine, but pointed out that if everything was on at the same time then it could potenially trip the fuse.. SO he recommended running a spur from washing machine power socket at that was under the worktop already

 

[OwainDIYer]

In many cases induction hobs have an installers setting that limits the maximum power the hob can draw overall.

Is he going to fit a new oven isolator switch above the worktop?

 

[Taylortwocities]

Is he going to fit a new oven isolator switch above the worktop?

WHy would that be necessary?

 

[OwainDIYer]

Good practice, surely, (along with grommets).

Especially if someone might otherwise assume that the cooker swithc controls the oven as well as the hob.

May be required by the manufacturers instructions.

I am one of those people who find a Big Red Switch next to the cooker comforting. (And on a few occasions the neon has alerted me to a ring left on unattended.)

 

[Taylortwocities]

I think that any additional terminations,switches and other stuff in high current circuits are a disadvantage. The stream of problems with shower pull switches bears this out.

 

[OwainDIYer]

Shower pull switches try to cram a 45A switch and all the cables into a single back box. And a shower is a full steady load. I'm not a fan of them either.

 

[ban-all-sheds]

I wonder why I've had no problems with my shower switch which has been in place now for nearly 15 years, gets 2-3 cycles per day.....

I wonder if quality product and competent installation might have any bearing on it?