Using pre installed cooker circuit for 13amp or 16amp oven.

[SUNRAY]

Yes it's a domestic kitchen there is already a dedicated circuit with 6mm cable going from 32mcb to 45cooker switch then 45a cooker connection plate then 6mm cable to cooker. But we are getting a smaller single oven which is only 16amp but need be hardwired. So should I change 32mcb to 16mcb I'm consumer unit or just get electrician to wire it straight into connection plate with cable supplied.

Hi Mark.

Please be aware winston1 is renowned for giving incorrect and sometimes unsafe advice.

Does the new new oven come with a flexible cable attatched?

The 'official circuit design criteria in the regulations' is all about protecting the electrical installation. ie; primarily to protect the cable and switches against overloads.
On that basis if the oven has terminals for a cable to be connected to and you are able to use the existing 6mm² cable, then the MCB may be left at 32A.

If the oven has a flex attatched which is then terminated in the wall connexion plate, the MCB rating should be chosen to protect that size of cable. IE if it's a 1.5mm² flexible cable (fairly likely) the MCB should be changed to 16A. This is often reflected in the manufacturers instructions where they may state a 15 or 16A fuse or MCB. Manufacturers will of course deny responsibility if something goes wrong and their instructions have not been followed.

A lot of my work is maintenance and too many times I've seen the excessive damage as a result of a fault with incorrect protection.

As has been posted a 30mA RCD will trip much quicker on some faults than a MCB.
Personally I will change the MCB regardless of what the regs say.

 

[Mark armitage]

Hi Mark.

Please be aware winston1 is renowned for giving incorrect and sometimes unsafe advice.

Does the new new oven come with a flexible cable attatched?

The 'official circuit design criteria in the regulations' is all about protecting the electrical installation. ie; primarily to protect the cable and switches against overloads.
On that basis if the oven has terminals for a cable to be connected to and you are able to use the existing 6mm² cable, then the MCB may be left at 32A.

If the oven has a flex attatched which is then terminated in the wall connexion plate, the MCB rating should be chosen to protect that size of cable. IE if it's a 1.5mm² flexible cable (fairly likely) the MCB should be changed to 16A. This is often reflected in the manufacturers instructions where they may state a 15 or 16A fuse or MCB. Manufacturers will of course deny responsibility if something goes wrong and their instructions have not been followed.

A lot of my work is maintenance and too many times I've seen the excessive damage as a result of a fault with incorrect protection.

As has been posted a 30mA RCD will trip much quicker on some faults than a MCB.
Personally I will change the MCB regardless of what the regs say.

Thanks the oven is being delivered next Thursday so will check cable on it then. If it's 1.5mm cable would I just need get electrician to change mcb to 16a and wire cable to existing connection plate and keep cooker socket and rest 6mm cable in place

 

[SUNRAY]

Thanks the oven is being delivered next Thursday so will check cable on it then. If it's 1.5mm cable would I just need get electrician to change mcb to 16a and wire cable to existing connection plate and keep cooker socket and rest 6mm cable in place

Yes that is spot on.

 

[Mark armitage]

Yes that is spot on.

Hi again oven came today it's has a flex cable on it. It's stamped H05VV-F 3G 1.5. so guessing it's a 1.5mm cable will this be ok to connected to connection plate that is in wall and just changed MCB to 16amp or would I need change cable to 2.5mm on 16amp MCB. Cheers

 

[JohnW2]

Hi again oven came today it's has a flex cable on it. It's stamped H05VV-F 3G 1.5. so guessing it's a 1.5mm cable will this be ok to connected to connection plate that is in wall and just changed MCB to 16amp or would I need change cable to 2.5mm on 16amp MCB. Cheers

1.5mm² flex is (just) OK for 16A.

Kind Regards, John

 

[SUNRAY]

Hi again oven came today it's has a flex cable on it. It's stamped H05VV-F 3G 1.5. so guessing it's a 1.5mm cable will this be ok to connected to connection plate that is in wall and just changed MCB to 16amp or would I need change cable to 2.5mm on 16amp MCB. Cheers

The oven manufacturers have fitted it, therefore it is appropriate. depending of which lists are referred to the cable is rated for around 16A.

That installation will be trouble free for a long time.

 

[Mark armitage]

The oven manufacturers have fitted it, therefore it is appropriate. depending of which lists are referred to the cable is rated for around 16A.

That installation will be trouble free for a long time.

Thanks the manufacturers say to hardwire to a 13 amp fuse spur but the cooker is 3.3kw a electrician said 13amp wouldnt be big enough and it may melt the fuse so just wanted check the 1.5mm cable would be ok.

 

[EFLImpudence]

Looking back to your original post:

13amp oven
Requires hardwiring to a 13 Amp fuse
Power supply 13 Amp (Requires hardwiring to a fused spur)
Electrical power rating 3.3 kW

16amp oven
Electrical installation- Requires hardwiring to a 16 Amp fuse.
Power supply 16 Amp (Requires hardwiring to a dedicated circuit)
Electrical power rating.3.3 kW

Can't all be correct, can it? So, which bits are right and which bits are wrong?

 

[Mark armitage]

Looking back to your original post:



Can't all be correct, can it? So, which bits are right and which bits are wrong?

That info was on Curry's site.we went with oven what says on currys to wire into 13amp fuse spur. it's a hisense BSA5221ABUK.
Can't find anywhere in instructions about installation and what amp fuse is needed only information it gives is its 3.3kw.

 

[JohnW2]

Looking back to your original post: .... Can't all be correct, can it? So, which bits are right and which bits are wrong?

I wondered that at the time.

I wonder if they are both from the same manufacture? If not, then if they were both 3.3 kW (at 240V) that would be about 13.18A at 230V, so it could be that two different manufacturers had different approaches to saying how a "13.18A (peak) load oven" should be fitted (and maybe for different markets) - with one feeling that 13.18A was close enough to 13A for it to be hardwired to a (13A) FCU in UK, and the other feeling that anything over 13A (even if only fractionally) needed a 'fuse' rated higher than 13A (and maybe directed at non-UK markets).

... just some thoughts!

Kind Regards, John

 

[Mark armitage]

I wondered that at the time.

I wonder if they are both from the same manufacture? If not, then if they were both 3.3 kW (at 240V) that would be about 13.18A at 230V, so it could be that two different manufacturers had different approaches to saying how a "13.18A (peak) load oven" should be fitted (and maybe for different markets) - with one feeling that 13.18A was close enough to 13A for it to be hardwired to a (13A) FCU in UK, and the other feeling that anything over 13A needed a 16A 'fuse' (and maybe directed at non-UK markets).

... just some thoughts!

Kind Regards, John

Yeah there both the same make that what was confusing as there both 3.3kw but installation is different but there both hisense ovens

 

[JohnW2]

Yeah there both the same make that what was confusing as there both 3.3kw but installation is different but there both hisense ovens

Interesting. If they both really are 3.3 kW (peak), then they obviously would both draw the same peak current (at any voltage). The one with the reference to the 13A fuse is clearly intended for the UK markket, whilst the reference to a "16A fuse" sounds more like it was intended for mainland Europe. I don't suppose they are both the same product, are they, just with different part numbers and different instructions? Were they the same price?

Kind Regards, John

 

[Mark armitage]

No there were different prices I put links below to each one
https://www.currys.co.uk/gbuk/house...m-add-black-stainless-steel-10209128-pdt.html

https://www.currys.co.uk/gbuk/house...228pbuk-electric-oven-black-10200559-pdt.html

 

[JohnW2]

No there were different prices I put links below to each one....

Thanks. Very odd!

Kind Regards, John

 

[EFLImpudence]

As there is absolutely no difference between an FCU and a socket and plug, it surely - for sale in the UK - should be supplied with a moulded plug on the flex if suitable.

This from the first link above:

You will note that it states "Power supply" [not fuse]- 13A. (Requires hard wiring to a fused spur) -
This must be written in the UK because of the incorrect use of 'fused spur'.

The other one states "Power supply" - 16A (Requires hardwiring to a dedicated circuit) -
This appears to be the normal for appliances in Europe.

as they are both quoted at 3.3kW something is not right,