electrical board safety

[nome]

hello

our old cooker has packed up and were looking to replace with like for like, A single electric fan oven that slides into a unit. The old cooker was just plugged into a socket and looking around most products seem to be hardwired in and require an electrician. Confusingly I can't find anything that explains why some are socket based and most are hardwired.

So we got an electrician in that quoted for, a hardwired oven, a wire running back to our board. Then looking at our board he said it did not meet current regs and recommended, if we want, a newer board either with a RCD on the main switch or RCDs on 2 separate sections. This work also required testing all our electrics. The total cost is a lot more than buying another socketed oven! :)

Looking at our board it says the following:

mk sentry consumer unit to BS 5486 PT13 1989

60a with rcd to 63a rated with current switch disconnection

googling BS 5486 PT13 found this

was wondering if we need to replace? And I believe our box has an RCD as well? Should we spend =A3300 on the cost of upgrade/hardwired oven or just get another socket oven? Our hob is gas by the way.

Hopeful of any advise

cheers

Nomit

[John]

our old cooker has packed up and were looking to replace with like for like, A single electric fan oven that slides into a unit. The old cooker was just plugged into a socket and looking around most products seem to be hardwired in and require an electrician. Confusingly I can't find anything that explains why some are socket based and most are hardwired.

So we got an electrician in that quoted for, a hardwired oven, a wire running back to our board. Then looking at our board he said it did not meet current regs and recommended, if we want, a newer board either with a RCD on the main switch or RCDs on 2 separate sections. This work also required testing all our electrics. The total cost is a lot more than buying another socketed oven! :)

Looking at our board it says the following:

mk sentry consumer unit to BS 5486 PT13 1989

60a with rcd to 63a rated with current switch disconnection

googling BS 5486 PT13 found this

was wondering if we need to replace? And I believe our box has an RCD as well? Should we spend £300 on the cost of upgrade/hardwired oven or just get another socket oven? Our hob is gas by the way.

Hopeful of any advise

cheers

Nomit

Have you noticed a difference in the wattages of the various ovens? Is there a co-relationship between plug and hardwired wattages?

[Andrew Gabriel]

IME, most ovens run from sockets with a max load of about 2.5kW. You need to go to really big ones before they have to be hardwired.

Your installation does not need to be brought up to current regs, providing it still conforms to the regs in place at the time it was last installed/modified, and isn't unsafe. Lots of electricians try this one on.

Put a picture of it up on a website somewhere.

I was wondering if we need to replace? And I believe our box has an

The new circuit needs to conform to current regs, and therefore is going to need to be on a 30mA RCD unless none of the wiring is buried in the walls. If you have a spare way which is on an RCD (can't tell from what you've said if that's the case), then electrician can use that (subject to checking loadings, etc). Earthing for the installation should be brought up to current regs too.

[David WE Roberts]

our old cooker has packed up and were looking to replace with like for like, A single electric fan oven that slides into a unit. The old cooker was just plugged into a socket and looking around most products seem to be hardwired in and require an electrician. Confusingly I can't find anything that explains why some are socket based and most are hardwired.

Have a look in B&Q - they always seem to have a load of single electric fan ovens on offer. The one we got a year or so ago could be connected to a standard 13 amp socket.

On the (volts * amps = watts) front a 13 amp socket should support at least

3 Kw and as Andrew has said most don't consume more than 2.5Kw.

I was expecting the electric cooker to require a dedicated circuit (we already had one in place) but all it required was a 13 amp socket.

I think that kickass double ovens may well require more go juice but you should be able to find a single oven to meet your requirements. Decline the services of the electrician :-)

[NT]

You've not supplied a pic of the setup, but if its post 1989 as you say then its not likely to need any work.

All ovens that eat less than 3kW max, ie nearly all single ovens, can go on a plug, regardless of what their fitting instructions say. Ovens of the type that include a built in hob usually draw too much power to run off a 13A plug.

NT

[The Medway Handyman]

I was also wondering if the OP meant 'oven' or 'cooker'. Usual case is oven plugged in, electric hob wired in.

[John Whitworth]

He said it was a single, electric fan oven.

Anyway, like most replies here, we have a single electric fan oven, which is plugged into a non-switched 13A socket at the back of the unit. That's then connected to a cooker switch and 13A socket above the work surface. That cooker switch/socket is then connected into a seperate 32A MCB at the CU. But the main thing is that the cooker itself came with a 13A plug connected to it when we bought it.

[John Whitworth]

Oops - oven not cooker...oven not cooker!!! ;-)

[S Viemeister]

What is usual with dual-fuel cookers? Is the oven part wired-in or plugged in?

[ARWadsworth]

I often get around this by installing a new CU next to the existing one if the existing one is not suitable.

A small inexpensive 2 way RCD main switch CU unit can save a customer quite a bit of money.

Adam

[Andrew Gabriel]

Usually plugged in IME.

[nome]

hello wonderful advice - cheers pix at

did twig that just under 3KW was going to be the limit on a socket but found some products that still require hardwiring even though less than 3kw so that confused me :) Cheers again!

[Andrew Gabriel]

with the perspex lid. It's even got the 100A switch (often the small ones are only fitted with the 63A switch).

There's a spare way at the end, and these will take MK's current RCBO's if you need RCD protection, so it should be quite easy.

[js.b1]

Some may require "hard wiring" by virtue of the thermal limitations of a BS1363(/A) plug.

- It is not good practice to wire a 3kW immersion off a 13A plug, since it can draw 3kW for prolonged periods (hours).

- It is reasonable to wire a 3kW oven off a 13A plug, because it will only draw 3kW for short periods unless the door is left open.

I'm not convinced the heating effect is down to pin contact area, I think a significant amount is the thermal dissipation of fuse holder- tabs & fuse (combined 8W or so) which heats both flex & fixed wiring. Hence using a fused-spur for "hard wiring" does not gain you much either. I found my JL tumble dryer plug was blazing, changed it to an MK 1363/A and it now runs almost cool.

Alternatively the requirement for "hard wiring" when 3kW may as much be to prevent it being plugged into a 2G socket (shared with say a tumble-dryer) or into a multi-way adapter (which should be fused but might not be if very old).

You can get larger MK Sentry-1 boards (12-way) incidentally - they are on Ebay currently about =A324. Note that Sentry-1 & Sentry-2 are incompatible, Sentry-1 seemed tougher than the flimsy later offerings. Getting spare Sentry-1 parts is difficult. To identify Sentry-1 the CPD cover is translucent smoked grey, Sentry-2 is a solid cream colour.

[nome]

Hello

Looking at the unit it mentions "60a with RCD to 63a" I'm presuming the unit already has an RCD albeit one that is for the whole installation? Is this correct?

So IF I just buy another socket based oven Do I need (additional) RCD/ MCB/RCBO protection?

Cheers

Nomit

[S Viemeister]

That's good - I'm awaiting the delivery of a dual-fuel cooker, and have been arranging for installation of LPG cylinders (no mains gas where I am) - nice if I can just plug the thing in!

[Mike Clarke]

Some suppliers seem to be far too cautious (or careless) when it comes to supplying this type of information. For example Ikea GAS hobs are described as "Wired-in installation. Installation to be made by a qualified electrician." (e.g.

- just for the fraction of an amp needed for the piezo spark generator, well within the capacity of a plug and socket. It's probably just standard boilerplate labelling which they apply to all hobs and ovens without thinking.

[Andrew Gabriel]

No. It looks like the CU was originally sold with an RCD, but there isn't one in there anymore.

Not if you can simply plug it in.

[John Rumm]

No, that's just telling you the maximum rating with two different alternative main switch devices. So with a main switch (what you have) is 60A, or with a RCD (which you don't) its 63A

No. You don't really need one for a hardwired one either, however that would require a new circuit, and due to the wording of the 17th edition of the wiring regs, it is hard to avoid the use of a RCD for most circuits.

[nome]

Cheers

Odd that it would have had the RCD taken out...

Anyway thanks for all that - I think I'll leave everything as it is and just buy a socket oven! cheers again for all your advice