Are oven manufacturers lying to us?

[Kkiernan09369]

So there’s a hotpoint oven hae60ks....

The manual states its10.7 kw....divided that by 240 is 45amps.

The manual also states is must be installed with a 6mm cable connected to a 32amp breaker.

Some people online are saying a 6mm cable is max rated at 32amp

But i read that clipped direct it’s max rated to 47

So my basic question is... I have a 6mm cable running up 2 meters stud wall, above the ceiling for 12meters no insulation and then 2 meters down another stud. It’s currently on a 32amp breaker.

Is this going to be sufficient enough? With diversity taken in to account it’s doable. But my missus cooks 3 different meals everyday for dinner.

I also read that a Type B 32amp breaker won’t trip out untill about 3-5 times it’s rating which is what? 90amps?

 

[Baddegg]

If that’s what MI says them that’s it....sounds like they’ve done the diversity for ya?

 

[rapparee]

But the thing is.

Your wife is unlikely to have 4 rings and two ovens on at once.

And a 32A breaker will trip long before 90A

 

[Silly Sausage]

But the thing is.

Your wife is unlikely to have 4 rings and two ovens on at once.

That could be misconstrued in so many ways ...

 

[telectrix]

So there’s a hotpoint oven hae60ks....

The manual states its10.7 kw....divided that by 240 is 45amps.

The manual also states is must be installed with a 6mm cable connected to a 32amp breaker.

Some people online are saying a 6mm cable is max rated at 32amp

But i read that clipped direct it’s max rated to 47 correct

So my basic question is... I have a 6mm cable running up 2 meters stud wall, above the ceiling for 12meters no insulation and then 2 meters down another stud. It’s currently on a 32amp breaker.should be fine

Is this going to be sufficient enough? With diversity taken in to account it’s doable. But my missus cooks 3 different meals everyday for dinner.

I also read that a Type B 32amp breaker won’t trip out untill about 3-5 times it’s rating which is what? 90amps? breaker will trip instantaneously @ 5x it's rating. it will wirthstand overload for a certain amount of time, the time being inversly proportional to the current. e.g. it can handle 1.4x rating for about 1 hour. even this ( 32 x 1.4 =45A) is within the capacityof 6.0mm cable clipped direct.

my comments in red. you need to expand the post to read.

hope that alleviates your fears. for 60+ years it's been accepted that a 32A circuit, 6mm cable will handle any cooker up to 15kW (diversity applies).

 

[rapparee]

That could be misconstrued in so many ways ...

I honestly don't get it, I'm searching for a double entendre somewhere

 

[AJshep]

Agree with tel. The only time you would take diversity out of the equation would be if it were a commercial kitchen.
Even with everything running flat out the thermostats would kick in a different times

 

[westward10]

Is this by any chance the same as this thread?

Need a different mcb

Hi al it’s not. DIY job I’m aware of that. But I have just purchased an electric range cooker. Had an electrician out to extend cooker cable and he told me the instructions Manila of the cooker required a 40amp MCB. I’m not really in the market as of yet to be changing the consumer unit and I...

www.electriciansforums.net

 

[Kkiernan09369]

Thank you all for the replies.

 

[Kkiernan09369]

It is the same principle of the post but different oven now. Much smaller. But I wanted to be clear about the manufactura installation guide crossed with the Part P wiring regs

Is this by any chance the same as this thread?

 

[westward10]

No worries. It would not have been a problem to carry on your old thread as it would become active again once you enter a new post, saves going over old ground.

 

[Simon47]

I think what's missing from the replies above and in the other thread is an explanation of diversity. ...
If you were to go along the knobs and turn them all on full as fast as you can, then the cooker will draw it's rated current - and this is likely to be higher than the supply MCB rating. However, it can't draw this current for long as the various elements will get hot and turn off (or get turned down) at some point - thus reducing the current drawn.
In general, things will get turned on at differnt times - eg oven goes on maybe hours before the meal, and different pans go on at different times (and get turned down so they don't boil over).
Now the typical "B curve" 32A MCB doesn't trip at 32.1A. The specs only require it to trip "instantly" at 5x it's rating which is 160A (that's for a fault, nominally short circuit). For overload, it'll carry 2x it's rating (64A) for "a while". This overload capability and the diversity described above means that you'd need to be trying in order to trip the MCB and you wouldn't do it in normal use.

Cable current carrying ratings take these factors into account . So drawing (say) 40A from a B32 MCB for a short time will not overload the cable if it's been correctly specified and installed according to the tables in our "bible" - BS7671, a.k.a. The Wiring Regs. That's for the UK, other countries have their own rules but with the same end result.

 

[Kkiernan09369]

I see what your saying. I’m a very paranoid person and a very tight person. So I’m paranoid of fire and I’m too tight to upgrade the CU and oven cable

So above all the above replies have settled my mind. Hopefully the electrician they send will plug it in this time.

 

[Simon47]

Better to be cautious and find out that it's OK than the other way round

 

[GeorgeCooke]

You don't even need 6mm cable. On a 32amp breaker 4mm is sufficient. Think 4mm radials on 32a breakers.