Quick Cooker Question

[timo]

Went to a job last week. No cooker feed to a new kitchen that been fitted this week. Customer thought they could use the socket that the old oven used. (old hob was gas) anyways i ran a 6mm to the kitchen and 6mm tail for the hob to connect to as the customer didnt know the rating etc and just said it would be a normal cheap ish cooker.

Been back today and the hob is noraml as she said but the instructions say 2.5mm to the terminals on the hob ??????? no way will the 6mm twin i put in fit in the terminals its just too damn big.

Am i right thinking that the manaul is onabout using 2.5mm Flex and not twin. How do i go on with the 6mm feed i put in for the supply and the 6mm s/w to the hob.

Looked in the onsite guide at diversity and i get the following.
10A + 30% of the remaining + 5A if there is a socket (there is) outlet on the switch.

Hob is 6200watts

6200/240 = 25.83A

so i have 10A for a start + 30% of remaining 15.83A = 4.79A + 5A

total = 19.79A

Is this correct?

What size breaker would be best to use. Wouldnt it trip with a 20A ?

Bit lost here guys... thanks

 

[bugsy]

I would not apply any diversity for the hobb use the 6mm and fit crimp ring terminals

 

[pennywise]

The manufacturer means 2.5mm HO7RN-F Cable heavy duty appliance flex for the connection between the outlet plate and the hob.

 

[PC Electrics]

I too would use 2.5mm H07RN-F from the outlet plate to the hob. Make sure you use either cord end terminals or ring crimp terminals and not just put the flex under screw heads.
A 32A MCB will be fine.

 

[timo]

Thanks allot for your replies guys.

Is there no diversity for cooker hobs?

 

[pennywise]

Diversity applies to cooker hobs as well.

 

[timo]

Thanks penny.

Would my working out be correct ?

Also i have just looked and the rating of H07RN-F is 29A @ 2.5mm
Heat resistant 2.5mm is 25A

 

[pennywise]

Your calcs seem Ok I use 230v in mine but the difference is negligible , The current rating you've found seems fine for the HO7 its got a bit tougher rubber sheath so it wears better where abrasion is likely and it's heat resistant which gives it the higher current carrying capacity than the normal flex.

 

[PC Electrics]

I would use 4mm H07RN-F if it will fit in the terminals, but when the destructions say to use 2.5mm this is usually code for "don't even bother with 4mm cos it won't fit mate". The manufacturers use small terminals to save on costs.

Yes, discrimination can be applied to hobs. I get 15A, 20A with a socket.