Cooker and Hob Query?

[whazza2]

When taking into account diversity, one 6mm 32A circuit is sufficient but what if they are both on at same time and causes MCB to trip?

 

[Theorysparky]

Whazza

you are assuming both hob and cooker on full at the same time ????

if you feel there is a chance of this happening then you would need to rethink the requirements for both items

a 6mm and 4mm radial.....on 2 seperate 32amp mcb's

everybody is right with the diversity figures but

its your assessment of the circuit requirements,,,,,

what use is the kitchen for ??? a family of 20 ????

a catering company working from home (ie hot food sandwich van type)

there is also the cost involved....

 

[tom1]

post 6 pg 160 specs has sumed it up

i will sum it up further

a 30 or 32 amp circuit is USUALLY appropriate for up to 15kw and thats with a socket

i think induction hobs are an exception but USUALLY the hob and oven will be fine on a 32 amp 6mm cable

i rarely see 2 circuits for hob and oven except for next week were there are 2 which will most likly become 1.

patch has given you the diversity calc also

 

[PC Electrics]

Would it be better to go for a 32A 6mm for hob and a 25A 4mm for cooker?

Better how?

Better for you, more materials profit, extra installation work.

How better for the client, though?

 

[PC Electrics]

When taking into account diversity, one 6mm 32A circuit is sufficient but what if they are both on at same time and causes MCB to trip?

Well, yes there is an outside chance that the client could turn all hob points and oven and grille on at the same time from cold

However, there are 100s of 000's of cooking circuits out there with a 32A/6mm combo. I think it's fair to say the design is proven as being reliable.

As Specs suggests, follow the guidance given in the OSG.

Also have a think about diversity and why this circuit design works despite the (apparently) massive load. It really shouldn't be a difficult concept to grapple with.

 

[Apache]

Also have a think about diversity and why this circuit design works despite the (apparently) massive load. It really shouldn't be a difficult concept to grapple with.

Think how a hob or oven works - it has a thermostat on the ovens and the rings. Even though if you switched EVERYTHING on at once you could draw 56A

it's very unlikely. I don't have a copy of the BRB but we all know a 32A breaker can handle more than 32A for a time.

 

[whazza2]

I do agree with everything, the client stated they will probably use it all at once for christmas or big meals, just dont want to get a call saying its trip

They have also said that they are not keen on having an isolator as they would not use it and dont want it to be seen.

Could I just wire straight to an outlet plate?

 

[Apache]

They have also said that they are not keen on having an isolator as they would not use it and dont want it to be seen.Could I just wire straight to an outlet plate?

No - it's a regulation, local means of isolation within 2 meters. I have no regs book, but it's in there. You could put it in a cupboard if you must?

 

[Apache]

No - it's a regulation, local means of isolation within 2 meters. I have no regs book, but it's in there. You could put it in a cupboard if you must?

Been digging in the archive:

132.15.1 Effective means, suitably placed for ready operation, shall be provided so that all voltage may be cut off from every installation, from every circuit thereof and from all equipment, as may be necessary to prevent or remove danger.

OSG says should be within 2 meters.

 

[m4tty]

Mines in the cupboard next to the cooker

 

[batty]

I generally like to have them accessible but I am doing a couple of circuits in an existing kitchen at present they have an Aga but when its not being used they want a seperate hob and oven. I am putting the switches at the front of a couple of cupboards that way they are accessible if necessary and the decor does not have to be destroyed. I am happy with this as its the best I can do with the situation.

 

[whazza2]

Is it acceptable to chase cables into concrete floor?

 

[Badger]

Is it acceptable to chase cables into concrete floor?

yes no problem putting a cable through a concrete floor, BUT a conduit system or electrical ducting should be used to protect pvc cabling fromt he concrete.

 

[Bacon]

yes no problem putting a cable through a concrete floor, BUT a conduit system or electrical ducting should be used to protect pvc cabling fromt he concrete.

Plus cable can be drawn back out if you need to replace cables at some time.

 

[initforthemoney]

Separate radials every time.

Purely for convenience in the case of a fault with either appliance.