Change of cooker/oven

[Geoffsd]

There is no mention of 'like for like' in the regulations.
Will people please stop quoting it?

Because it is allowed, without notification, to replace a cooker with a hob and oven does not negate the need to know what you are doing.

A 32A circuit (without integral socket) is good for a combination of hob and oven of 19kW.

 

[Geoffsd]

Current is wattage divided by voltage. The wattage doesn't change which is determined by the resistance. Ohms law. Previous mr Owen is correct.

No he isn't.

The resistance (of the elements) is the only constant.

 

[ramonford]

Thanks to ever one for all the advise.

Just to try and make things clear the new oven is a separate unit and is to be connected into the existing ring which is a dedicated one for the kitchen. The hob which is also separate is to be connected to the old 6mm t &e rcd/mcb, the new hob is rated at 7.5 Kw, which is less that the total max load of the old cooker.
My installer is trying to push me into a full upgrade to make the cooker and earth wiring compliant with the latest regs.
This is going to cost upwards of £450.00 and seems difficult for me to justify.

Any further thoughts appreciated.

 

[Engineer54]

Thanks to ever one for all the advise.

Just to try and make things clear the new oven is a separate unit and is to be connected into the existing ring which is a dedicated one for the kitchen. The hob which is also separate is to be connected to the old 6mm t &e rcd/mcb, the new hob is rated at 7.5 Kw, which is less that the total max load of the old cooker.
My installer is trying to push me into a full upgrade to make the cooker and earth wiring compliant with the latest regs.
This is going to cost upwards of £450.00 and seems difficult for me to justify.

Any further thoughts appreciated.

So what does your installer actually want to do then?? What size earth (bonding) cable is presently existing in your home?? I take it this is what you mean by the term ''earth wiring'' above??

 

[lauriehurman]

Forgive me for going slightly off-topic but doesn't the principle of "discrimination" prevent you from putting a 45a fuse downstream of a 32a fuse?

Laurie

usually minimum 6mm T&E with 30a/32a protective device with a dual connection unit feeding both via a 45a switched FCU.

 

[jibjob]

Yes it would, I'm referring to the rating of switched FCU (fixed connection unit) as being 45a, double pole & often with integral 13a socket

 

[Deservices]

The 6mm t&e is fine for connecting to the new hob. What does the guy want to upgrade exactly? As the only thing I can think of from top of my head, may be the bonding to the water and gas.(should be 10mm).

 

[HandySparks]

Yes it would, I'm referring to the rating of switched FCU (fixed connection unit) as being 45a, double pole & often with integral 13a socket

I think the misunderstanding has arisen because the acronym "FCU" is generally taken to mean Fused Connection Unit.

 

[Engineer54]

Don't know what all the fuss is about, connect both oven and hob to the existing Cooker control panel via a dual connection unit, made for this very purpose!!! lol!!!

A 32A circuit (without integral socket) is good for a combination of hob and oven of 19kW.

A typical 6mm T&E on a 32A MCB is good for up to 15KW, ...not 19KW.

 

[ramonford]

Thanks for all the replies to my most recent post.

I will try and mop up all the questions asked in this single reply.

Please excuse if I do not always use the correct terms of the trade, but I am at the bottom of the learning curve so greatly appreciated all comments.

I have had 3 different quotes for the job of connecting the new hob/oven.
All all three quotations were for doing different things, by this I mean that no two quotes were for the same amount of work. Some wanted to fit a new separate RCD/MCC board, others a separate ring for the kitchen and some wanted to upgrade the existing 10mm bonding to 16mm. All quotes placed great importance on the need to have the kitchen electrical supply upgraded to the very latest regulations. When I asked further and said would this apply if I was to go and buy a new cooker off the shelf and have this installed. At this point things started to get nasty and I was told quite firmly that they had been in the trade for ## years and this was their advise and I should accept it with out question. I could go a lot further on this but feel it would serve no useful purpose. I do accept advise readily but consider it justifiable to be allowed to ask on the detail, in most cases this was not forth coming.

So the end result is I still do not known what if anything I should have done to get my appliances connected. By this I mean connect the oven the the existing kitchen ring and use the existing 6mm cooker circuit to the new hob.I would like to be in a position to be able to say this is the job spec that I want quoted and not have to enter into a protracted discussion over the ins and outs of many baffling alternates.

Thank you for staying with me on this post. Obversely price is always a consideration that is why I am trying to understand what is the most cost effective way for me to get the job done.

 

[Deservices]

Ast for a quote for. Main earth and gas 10mm bonding if not already done. Rcd/MCB protection for existing 6mm cooker point. Cooker connecting to existing main and hob to exciting 6mm cooker point. This would be up to existing regs.

 

[Geoffsd]

A typical 6mm T&E on a 32A MCB is good for up to 15KW, ...not 19KW.

That's with an integral socket. I did say without.

19000/230 = 82.61A - 10 = 72.61A x 0.3 = 21.78A + 10 = 31.78A

 

[ramonford]

Thank you.

I already have 10mm bonding at the main board connecting gas/water and distributing board. I already have a 6mm cooker feed backed up by a RCD/MCC. I also have a ring main available near to the new oven, so based on this is there any thing else I need to have done.

They say there is a new mug born every day and I don't want to be the next one.

 

[ramonford]

That's with an integral socket. I did say without.

19000/230 = 82.61A - 10 = 72.61A x 0.3 = 21.78A + 10 = 31.78A

Interesting arithmetic.

Please could you explain in a little more detail what it is trying to show.

 

[Deservices]

Interesting arithmetic.

Please could you explain in a little more detail what it is trying to show.

He is showing in regard to diversity with a oven. But saying a 6mm is good for 15kw is a invalid argument as its not.
seems to me all you need is the hob wiring to the cooker point.