Wiring for 2x 3.6kw ovens, & “Currys Team (don’t) Know How”

[BaldOldMan]

beedj said:

Agreed, except they shouldn’t have sold me an installation service for a hard-wired oven when the service appears to be limited to plugging in to a socket (which is what the guys said)

Did you read the link ?

It could well have been that they realised they shouldn't connect 2x16A ovens to a single 32A MCB - per the instructions it needs a 16A supply.

I'm sure there are many out there connected to 32A as many people have swapped from double to twin ovens - and it's probably how a double oven is wired internally.....

Do you have a full transcript of the conversation ?

They might have said something along the lines of they can't even swap to sockets - are you sure that is what they were actually proposing from the outset ?

The instructions say hard wire because you may need 16A one day and that's the only way to get it,. There's nothing dangerous about having a plug rated for 13A with a 13A fuse in it.

Anyway - it's up to whatever your electrician advises now.

[Sheepshanks]

BaldOldMan said:

There's nothing dangerous about having a plug rated for 13A with a 13A fuse in it.

Some experience in practice:

https://www.diynot.com/diy/threads/13a-plugs-will-...

[beedj]

BaldOldMan said:

They might have said something along the lines of they can't even swap to sockets - are you sure that is what they were actually proposing from the outset ?

The instructions say hard wire because you may need 16A one day and that's the only way to get it,. There's nothing dangerous about having a plug rated for 13A with a 13A fuse in it.

Anyway - it's up to whatever your electrician advises now.

They definitely said 3-pin sockets/plugs - my wife even queried it with them and they referred to the regular kitchen sockets and said 'like these'

[EarlofDrift]

Better they told you they weren't qualified than bodged it and left a heap of problems, sometimes you just can't win. If they were electricians then I doubt they'd be working for not much more than minimum wage for Currys.

I once worked for a company that sold power showers and had a customer ask me to do a drawing of how to connect his shower up to run on mains gas. He actually got quite irate when I told him he'd need a gas safe registered plumber to do it.

'But I know roughly what to do ' he said.

'Well roughly won't rebuild your house if you blow it up'

[Aluminati]

Initforthemoney said:

Sheepshanks said:

Appreciate what you're saying re plugging it in, but it's not considered good practice to use a plug and socket for ovens even within the rating.

Really?

It was always my understanding that a single oven will come supplied with a 3 pin plug.

Doubles which usually have a grill as well require hard wiring in cable suitable for the task.

I would not expect Currys to have a sparks delivering ovens, and i would want anyone hard wiring my oven (s) to be suitably qualified to do so.

Basically, Currys mugged you for £90 oven disposal ?

[Mr Pointy]

Aluminati said:

It was always my understanding that a single oven will come supplied with a 3 pin plug.

Doubles which usually have a grill as well require hard wiring in cable suitable for the task.

I would not expect Currys to have a sparks delivering ovens, and i would want anyone hard wiring my oven (s) to be suitably qualified to do so.

Basically, Currys mugged you for £90 oven disposal ?

Try reading this which was posted already:
https://www.currys.co.uk/gbuk/cooker-install-426-c...

Then maybe come back with something useful?

[beedj]

Aluminati said:

It was always my understanding that a single oven will come supplied with a 3 pin plug.

Doubles which usually have a grill as well require hard wiring in cable suitable for the task.

I would not expect Currys to have a sparks delivering ovens, and i would want anyone hard wiring my oven (s) to be suitably qualified to do so.

Basically, Currys mugged you for £90 oven disposal ?

No plug fitted - came with bare wires ready to be hard wired - as per instructions. The Currys guys wanted to fit a plug

I didn’t even get disposal of the old ovens hor the packaging for the new) - I forgot to say they wouldn’t remove the old ones either, as they were hard wired . I’ll be getting my £90 back

[BaldOldMan]

I think they did the best they could in the circumstances.....

They identified that they could not connect the two 16A ovens to a single 32A supply.

What would you have liked them to do next ?

I'm guessing that removing the old ones & leaving you without an oven is not the right answer.....

[Aluminati]

Mr Pointy said:

Try reading this which was posted already:
https://www.currys.co.uk/gbuk/cooker-install-426-c...

Then maybe come back with something useful?

The link you post mentions fitting “ By our qualified electrical engineers”

The ‘Qualified electrical engineers’ delivering the op’s ovens informed him, “ We’re not qualified electricians”

Is there a difference ?

Do you have anything useful to add, or just in the mood for being a rude prick ?

[BaldOldMan]

OP has a second hand account of the conversation and has jumped to some conclusions.....

I'd suggest that OP starts by inquiring as to the reason that they didn't complete the install rather than continuing with the assumption that the installers were dangerously incompetent - and take it from there.

The Curry's site clearly states that the installers should be qualified enough to install and issue a certificate if hard wired.

They are not offering a full electrician service, regardless of what qualifications the installer may or may not have - we are not electricians - we are not fully qualified electricians - etc etc may well be true - but equally, isn't relevant.

[beedj]

BaldOldMan said:

I'd suggest that OP starts by inquiring as to the reason that they didn't complete the install rather than continuing with the assumption that the installers were dangerously incompetent - and take it from there.

Yes I'll be doing this tomorrow, but (categorically) they told my wife we needed two 13A plug sockets in order to proceed - despite the appliance lead not having a plug fitted. They wouldn't have known this as they didn't remove the oven from packaging - but it's clearly stated on the oven spec on Currys website

I will report back on progress with Currys and with my electrician :-)

Edited by beedj on Sunday 20th October 19:35

[Initforthemoney]

Let’s face it op.

The first mistake was buying from currys

[BaldOldMan]

Initforthemoney said:

Let’s face it op.

The first mistake was buying from currys

LOL

OP - I hope your complaint is successful - but always useful to consider their perspective when preparing - and it seems they did send 2 guys, so have incurred costs

They seem to be providing 3 services - delivery - installation & removal.

Would delivery have been free or charged otherwise ?

You know the questions to ask regarding installation.....

Did they offer removal ? Seems like there's no reason they couldn't have removed the old ovens & packaging if you'd wanted them to.

[Black_S3]

Aluminati said:

Mr Pointy said:

Try reading this which was posted already:
https://www.currys.co.uk/gbuk/cooker-install-426-c...

Then maybe come back with something useful?

The link you post mentions fitting “ By our qualified electrical engineers”

The ‘Qualified electrical engineers’ delivering the op’s ovens informed him, “ We’re not qualified electricians”

Is there a difference ?

Yes. They’re domestic electrical installers.... it’s just a few weeks worth of courses.

[talksthetorque]

Curry's ts and cs said:

The specification section on each of our products lists the electrical power rating along with the fuse requirement. Our product pages also let you know if the appliance comes with a plug fitted or if this should be installed by a qualified electrical installer, like one of our Team Knowhow Experts.

Should Curry's have sent someone qualified to fit hard wired cookers, who would then have identifed that you didn't have the correct protection devices, rather than incorrectly asking for somewhere to plug a 3 pin 13A plug in.

[Aluminati]

Black_S3 said:

Yes. They’re domestic electrical installers.... it’s just a few weeks worth of courses.

Don’t need to comply with Part P ?

[beedj]

Update #1 : Spoke to Currys, full refund issued for installation - no quibble whatsoever ("Judging by the notes we've clearly sent somebody not qualified to do the job")

[ruggedscotty]

Ive done this before.....

bring supply to a small local consumer unit, use 2 16A MCB's and feed the cookers from the 16A MCB's via 20A DP local switches. Simple solution and will get it up and running for you. using 13A sockets I would not advise. A 13A socket plug at 13A will if run at 13A for a long time get warm. It is also not being plugged in and unplugged so the natural self cleaning of the pins and wipers in the plug / socket is not happening and as a result of that contact resistance will build and you will get heat produced in the socket plug combo.

Try to keep it fixed wiring if you can.

[MJNewton]

I am surprised that no one has mentioned 'diversity' yet (apologies if I missed it!) as this is the key starting point when working out the current capacity requirements of cables for ovens. Basically, it reflects the fact that ovens are intermittent heating devices (the heat input far outweighs the heat losses so a thermostat is employed to cycle the power once up to temperature) and hence they do not draw the full rated capacity continuously. The supply cable does not therefore need to be sized to accommodate the full load continuously.

The calculation for working out the current carrying capacity requirement of the supply is 10A + 30% Remainder of the Full Load Current (+5A if a 13A socket is provided at the outlet). In this instance it is:

10A + (0.3 x ((2 x 3600W/230V)-10A)

= 10A + (0.3 x ((2 x 15.65A)-10A)

= 10A + (0.3 x (31.3A-10A))

= 10A + (0.3 x 21.3A)

= 10A + 6.39A

= 16.39A

A 6mm2 cable is rated to carry 29A in the worst-case installation environment (enclosed in an insulated wall) and thus this, with a 45A-rated DP isolator, is more than adequate to supply the two ovens together. This was to be expected at the outset as 6mm2 is by far and away the most common ‘cooker’ (hob and oven in any combination, whether combined or separate) supply cable size and ovens take the minor share of this. A dual cooker outlet plate is the easiest way to supply to multiple appliances rather than trying to squeeze everything into a single outlet.

Edited by MJNewton on Monday 21st October 14:29

Edited by MJNewton on Monday 21st October 14:31

[BaldOldMan]

You've answered a different question

I don't think anyone questioned the 32A supply - but is it OK to wire 2 x 16A governs directly to that with no additional protection as is OP's existing installation.

The probability of a fault occurring & drawing >16A but <32A is low - so arguably OK just to connect them up. However, to do it properly, each appliance should have it's own protection.