Rewiring Bungalow and circuit design for Kitchen.

[sweeneyuk]

Hello,

I am getting a bit bogged down with detail as I always try my best to meet every best practice but I am very out of practice as I have been working outside the industry for 15yrs. All help appreciated.

I am refurbishing my small 2 bed bungalow and have some questions for all the experts out there.

I have fitted a new metal 10 way consumer unit and have already run a separate 6amcb circuit for the loft mounted boiler, a 16a mcb to a general purpose & AV cupboard/ room.
I have run a ring main for the 2 bedrooms and am considering extending this for the living room or should I just run a 16a radial for living room?

My main issue is the kitchen!
Wife wants a double oven and induction hob and is the kind to have both ovens and most hobs on the go being a bit foody.
I have read on NEF site that you dont apply diversity to an induction hob, correct?
As both ovens are likely to be on at the same time I have come to conclusion I will run 2 x 6mm radials, 1 for each. Oven =6.5kw & hob 7kw, ok so far?

I have got in a muddle with regards to applying diversity to remaining kitchen appliances.
Microwave is a 800kw grill too but understand its only one at a time so consumption is rated at 1.4kw.
Washine machine=1.5kw
Dishwasher= 2 kw
Fridge/freezer=0.4kw
Wine cooler= 0.1kw
then theres the 2.2kw toaster and 3 kw kettle!
Thats 10.6Kw / 46A!!! before any other stuff is plugged in!

I've been trying to find details on how to properly diversify kitchen but only ever get the cooker calculation (on separate in my case) or the total dwelling design current.

I know it's neigh on impossible that all these will be on at the same time but what is the correct way to calculate the diversity???

I have considered running a separate 2.5mm 16a radial for the microwave and poss another for dishwasher & washing machine?

If I did this could I run just a radial to supply rest of kitchen?

Also wanted to fit the scolmore click minigrid control panel which will now have 2x 6mm for hob/oven supply, 2x2.5 for microwave &washing machine/dishwasher, 1x2.5 if radial or 2 if ring to supply remaining modules like wine cooler, fridge freezer.
I understand you can no longer have the fridge freezer on a separate cct before the rcd?

to summarise.

How do I diversify the cable calc for kitchen & should I run more ccts?
Do I put remaining kitchen on ring or radial?
Do extend rear rfc to incorporate living room or run another radial (remember all AV will be in dedicated AV cupboard on its own radial)?

Then I have the next biggy, loft insulation!
Can I lay cable over it rather than secure to joists which will result in needing 2x 10mm cooker cable (wont work with minigrid)?
Is there a way to bypass this by running cable through some plastic pipe to avoid contact with insulation?
Do I remove all insulation and have to go to extra expense of insulating rafters?

I know its a lot but all help really appreciated.

 

[SJD]

There is a bit too much in the post to reply to every point, but a few comments re your "to summarise":

How do I diversify the cable calc for kitchen & should I run more ccts?
Do I put remaining kitchen on ring or radial?
Do extend rear rfc to incorporate living room or run another radial (remember all AV will be in dedicated AV cupboard on its own radial)?

Apart from the ovens/hob, I suspect most people (in the UK) would just put in a 32A RFC for all the rest of the kitchen stuff for a domestic house. I doubt you'd ever draw as much as 32A unless you made a point of switching everything on at once to try and trip the MCB.

The living room power will be pretty minimal unless you are powering anything large such as heaters, and probably doesn't matter which way you do it. But I am starting to think you might have been better installing a larger consumer unit, so perhaps extend the RFC to save using up a way in the unit.

Then I have the next biggy, loft insulation!
Can I lay cable over it rather than secure to joists which will result in needing 2x 10mm cooker cable (wont work with minigrid)?
Is there a way to bypass this by running cable through some plastic pipe to avoid contact with insulation?
Do I remove all insulation and have to go to extra expense of insulating rafters?

Can't you just route any cables that matter to avoid being buried under insulation? I'm not particularly a fan of just throwing the cables across the top of insulation. Some bunglalow lofts have purlins that you could clip cables to, or add one or more additional timber supports clear of the insulation?

 

[Williamshoeste]

hi, i was wanting to rewire my bungalow too but replacement of a db and rewiring healthy cables are notifiable jobs and I'm not part of any schemes.

how do you plan on achieving the part p bit? just so that it might be something i could do as well

 

[Ed Evans]

Hello,

I am getting a bit bogged down with detail as I always try my best to meet every best practice but I am very out of practice as I have been working outside the industry for 15yrs. All help appreciated.

I am refurbishing my small 2 bed bungalow and have some questions for all the experts out there.

I have fitted a new metal 10 way consumer unit and have already run a separate 6amcb circuit for the loft mounted boiler, a 16a mcb to a general purpose & AV cupboard/ room.
I have run a ring main for the 2 bedrooms and am considering extending this for the living room or should I just run a 16a radial for living room?

My main issue is the kitchen!
Wife wants a double oven and induction hob and is the kind to have both ovens and most hobs on the go being a bit foody.
I have read on NEF site that you dont apply diversity to an induction hob, correct?
As both ovens are likely to be on at the same time I have come to conclusion I will run 2 x 6mm radials, 1 for each. Oven =6.5kw & hob 7kw, ok so far?

I have got in a muddle with regards to applying diversity to remaining kitchen appliances.
Microwave is a 800kw grill too but understand its only one at a time so consumption is rated at 1.4kw.
Washine machine=1.5kw
Dishwasher= 2 kw
Fridge/freezer=0.4kw
Wine cooler= 0.1kw
then theres the 2.2kw toaster and 3 kw kettle!
Thats 10.6Kw / 46A!!! before any other stuff is plugged in!

I've been trying to find details on how to properly diversify kitchen but only ever get the cooker calculation (on separate in my case) or the total dwelling design current.

I know it's neigh on impossible that all these will be on at the same time but what is the correct way to calculate the diversity???

I have considered running a separate 2.5mm 16a radial for the microwave and poss another for dishwasher & washing machine?

If I did this could I run just a radial to supply rest of kitchen?

Also wanted to fit the scolmore click minigrid control panel which will now have 2x 6mm for hob/oven supply, 2x2.5 for microwave &washing machine/dishwasher, 1x2.5 if radial or 2 if ring to supply remaining modules like wine cooler, fridge freezer.
I understand you can no longer have the fridge freezer on a separate cct before the rcd?

to summarise.

How do I diversify the cable calc for kitchen & should I run more ccts?
Do I put remaining kitchen on ring or radial?
Do extend rear rfc to incorporate living room or run another radial (remember all AV will be in dedicated AV cupboard on its own radial)?

Then I have the next biggy, loft insulation!
Can I lay cable over it rather than secure to joists which will result in needing 2x 10mm cooker cable (wont work with minigrid)?
Is there a way to bypass this by running cable through some plastic pipe to avoid contact with insulation?
Do I remove all insulation and have to go to extra expense of insulating rafters?

I know its a lot but all help really appreciated.

On site guide page 122 read it a few times and it down rates things quite a lot.
If you put the cable through some conduit it is still insulated although not touching as there is no air flow.
Kitchen should be on its own ring main. If ant other appliance is 2kw or more put it on its own radial.
Avoid radials a s if at a later date you want to add some more load the radial may not cope but a ring probably could.

 

[telectrix]

going back to OP,

Also wanted to fit the scolmore click minigrid control panel

what's the current rating of these. I'm sure they aren't capable of supplying cooking equipment.

 

[sweeneyuk]

going back to OP,

Also wanted to fit the scolmore click minigrid control panel

what's the current rating of these. I'm sure they aren't capable of supplying cooking equipment.

They do a 32a double pole specifically for oven and hob. 1 for each.
was going to run 2 x 6mm radials for oven/hob as manual for induction hob says no diversity should be applied.
[automerge]1588155964[/automerge]

On site guide page 122 read it a few times and it down rates things quite a lot.
If you put the cable through some conduit it is still insulated although not touching as there is no air flow.
Kitchen should be on its own ring main. If ant other appliance is 2kw or more put it on its own radial.
Avoid radials a s if at a later date you want to add some more load the radial may not cope but a ring probably could.

Was thinking of putting the washing machine & dishwasher on a separate 20a radial, 2.5 or 4mm? Insulation factor leans towards 4mm?
[automerge]1588156268[/automerge]

hi, i was wanting to rewire my bungalow too but replacement of a db and rewiring healthy cables are notifiable jobs and I'm not part of any schemes.

how do you plan on achieving the part p bit? just so that it might be something i could do as well

I completed c&g 2360 15yrs back and plan to do 18th edition then inspection & testing. Will ultimately sign it off my self at later date. Not how it should be done but I’ve seen some of the work out there, removed some seriously dodgy stuff from my bungalow already. Terminals tightened onto insulation, Spurs of Spurs, loosed wires just hanging out of terminals, wires joined by twisting together to name some.

 

[telectrix]

the important thing is to do it safely. OK you may be a bit rusty on the regs, but the basics haven't altered. and i didn't know about the 32A minigrid switches.