cooker circuit, border line.

[jedisparks]

Hi to all

Just wanted to get some opinions if poss. Im doing a kitchen electrics instal at the moment.

The hob that has arrived is rated at 7500watts and the the oven is a combination oven/microwave and is rated at 1000 watts.

There is an existing 6mm t & e circuit in place backed up by a 32 amp mcb.

So loading requirements at 230 volts foe the hob is 32amps

oven is 4.3 amps ish

would you folks tend to use the 6mm for just the hob and take s/f/spur off the ring for the oven?
Im half tempted to run an additional 6mm radial from the board for the oven so as not too push the ring to much and also for future if the oven is changed for a higher rated unit.

Thanks for reading

 

[megthemaddog]

should be OK when you apply diversity to the cooker hob's and oven as all of it wont be on at the same time

Tim

 

[bugsy]

Seperate radial for hobb and oven . if your going to pull in another radial install 10mm for hobb and use existing for oven,

 

[flukey]

both the hob and oven will be fine on the existing 6mm

 

[jedisparks]

thanks so far, but how do you work out the diversity for an appliance? i assume thats how youve come to that thinking Flukey?

thanks again

 

[ezzzekiel]

for a cooker circ
take 1st 10A of load then 30% of remaining amps plus 5A if socket outlet incorporated

diversitity is applied in different ways for diff circuit types, but is pretty straightforward and uses the assumption that not all the loading will be on at the same time look in onsite guide for full explananation Appendix 1

 

[jedisparks]

great thanks. so for the design current would you use the load with diversity taken into account or before diversity. just tryin to work out if i can get away with the one 6mm radial or not.

total load of the 2 appliances is 37 amps at 230 volts. (before diversity).

thanks again

 

[ezzzekiel]

work out design current then appy diversity formula


you know IB and you got the formula, take 1st 10A of load then 30% of remaining amps plus 5A if socket outlet incorporated

=

 

[bugsy]

You cannot apply diversity to the hobb,

your circuit OCP is 32a and your connected load is 37a ( hobb and oven) 32.6a for your hobb

 

[jedisparks]

ok so that gives me 18.1 amps so all is good for one 6mm radial, right?

 

[flukey]

your 6mm will take the full load current before diversity is apllied assuming its a standard run etc etc so you dont need to worry too much about applying the diversity as your well in