Re-wire questions

Hi Seneca

where is this recomendation found..?? I had flick through the book but didnt come across it.. Mind you its hard enough at times to find something you know is in there..

 

Red Book
appendix 15.

 

Thanks..

 

Appendix 15 of BS 7671: 2008 gives advice on ring final circuits and sharing/spreading the load around the circuit. Item (iii) suggests that cookers, ovens and hobs over 2 kW should be on their own dedicated circuit. Why can?t ovens of less than 3 kW be connected to a ring final circuit via a suitable connection point such as a socket-outlet or fused connection unit?

Appendix 15 is intended to give guidance only. Such connection is not prohibited, provided that no part of the ring final circuit will be overloaded as a result.

Regulation number(s)

• 433.1.5

 

6mm dedicated break at 32 (rcbo in split loader non rcd side, or on side of dual rcd etc etc - don't know what DB you have)- run to 45 Amp cooker switch with socket if you want (observing 2 meter rule) - down to dual box observing zones (might have to fit a double backbox and loop through and plate to maintain zone observation) - one side cooker connection unit for hob and other side 13 Amp socket for oven - upgrade oven in future? - no probs..

That's the way to do it..

Don't forget to test the circuit op.

Zone Observation (scuse cruddy picture)

 

hi JP,

The two metre rule being the maximum distance from the Isolator and cooker connection plate?

Cheers
Fats

 

Afternoon Fats. I only put the two meters rule in because it has been said on the forum - tbqh I dont know anything about the rule as I do not read about them as such. To me the more important thing is how far away from the hob the cooker switch is - to close and its not good, and to far not really very good..so its a common sense thing really I suppose. I forgot what I usually measure - hang on let me check..not fitted units but its 330mm. Maybe 200mm is ok, maybe 150mm (but no nearer)

I don't know.

Draining board to socket edge? - I try and always work to a min of 500mm - but then again maybe 300mm is ok - certainly no nearer tbqh (not in my books anyway - don't care what the regs say tbqh - unless I am encroaching on them)

 

It should be within 2 meters from the Hob / Oven to the switch.. If you have two items connected to one switch each item should be within 2 meters of the switch.. As for sockets as JP said there is a guide of 300mm but no regulation for it other then all installed acessories have to be suitable for the enviroment they are installed in.

 

So gentlemen.... and I use the term very loosly........
When an MK Grid Plus sytem is used in a nice new largish kitchen....is the 2 meter rule applied ?
I think not.
RS

 

Hi RS. I was thinking that also (last night actually)

Bit loose all this isolation malarkey I've put local isolation switches in which I'm sure as heck I don't think I need (of course cooker /hob isolation switch is needed)- its not up to me though - the inspector has the final word.

I have got to cross bond my boiler in 10mm - just get on with it I suppose. Thats the way it is.

 

JP
If you have a double RCD board with MEB in place on main services(and including steel flues and metal waste pipes in contact with earth) there is no need to cross bond sinks,sink pipes, metal furniture in kitchens, bathrooms, kitchens, rads or boilers.
Hope this saves you work.
RS

 

JP

I thought it was only gas and water in 10mm.

If using 17th edition board, no supplementary bonding required on other metallic extraneousness parts??

 

Hi RS/Jitender. My extension wire is under BC and this is what the inspector wants - I cant argue, but I do know all the cross bonding etc is not needed. But hey ho that's the way it is. Messy clamps and 10mm - flipping heck.

 

if your BCO is asking you to carry out works that aren't required, you simply don't have to do them - he's just wasting your time and money

he'll be wanting to dictate the style of light fittings next

 

Hi RS

Must admit mate, cross bonding boilers seems a waste of time owing to the fact all the wrokings of the boiler were metallic!

Thank god its gone!

Do heating engineers still practise this???

 

Si FI
They probably do... as even the BC people dont know what they are doing.
But dont worry, by the next reg book it will be required again...probably.


Jitender
As noted above...Main Equipotential Bonding (now called Main Protective Bonding) is "generally" (unless the installation is supplied by plastic and run in plastic) required for gas, oil, water, metal flues, metal soil pipes if in contact with ground, metal frame of house (if its that style).
It is 'recommended' that if there is a plastic supply but metal system within the premise that the metal system be bonded on the metal side.  But some people will argue no doubt.
RS

 

Tbqh Sean I'll just do it - what the heck. The inspector comes form a company appointed by BC - I'm not really that bothered and the chap is a decent fellow. BC generally just lets me get on with things, and I must say it is well worth the fees they charge for inspecting the building sequences of my extension. The electrical inspection fee is seperate but again the price is not bad what they are charging. All in all very impressed with my local BC and electrical inspection company.

 

New forum format..

 

Well the post is in relation to a cooker / Hob and not general isolation points that you would find on a grid system.. The 2m rule applies to cooker hob isolation not general isolation of other appliances