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

[Mark armitage]

I see why you say that but it is ambiguous how he has posted the info, is this his own interpretation or the manufacturers guideline, also I would like to read it myself to see whether there is room for movement on this, there is a difference between spec'd manufacturers guidance saying 'at least 13/16 amp supply' and one that says 'this product requires fusing at 13/16amp'.

Thanks I got the info of Curry's website I've attached screenshots of it.

 

[Mark armitage]

This is not true. Memshield 2 produced 13A mcbs which I have fitted for a kitchen spec. Schneider also produced them although they are now discontinued. Wyle do a 13A combined mcb/rcbo/afdd 13A Double Pole 1 Module B Curve 6kA 30mA AFDD Combined RCBO - https://www.cef.co.uk/catalogue/products/4832498-13a-double-pole-1-module-b-curve-6ka-30ma-afdd-combined-rcbo

So if I went with 13amp oven should I ask for 13amp MCB or 16amp MCB to be fitted what would be best?

 

[brianmoooore]

This is not true. Memshield 2 produced 13A mcbs which I have fitted for a kitchen spec. Schneider also produced them although they are now discontinued. Wyle do a 13A combined mcb/rcbo/afdd 13A Double Pole 1 Module B Curve 6kA 30mA AFDD Combined RCBO - https://www.cef.co.uk/catalogue/products/4832498-13a-double-pole-1-module-b-curve-6ka-30ma-afdd-combined-rcbo

I simplified my post for a DIYer. I'm fully aware that you can get MCBs in almost any rating you want, but the chances of the OP finding anything other than 6, 16, 20 and 32 in the range in question, available, and suitable for fitting in his CU, are negligible.
Of more concern is manufacturer's instructions for a 3.3kW @ 230volt appliance to be fed through a 13Afuse. 3.3kW @ 230v = 14.35A

 

[Dartlec]

Thanks I got the info of Curry's website I've attached screenshots of it.

Unfortunately websites are very bad at giving the useful information on ovens/hobs etc.

In this case, the manual for the hisense bsa5221abUK doesn't help either -as it says "Instructions for installation and connection are supplied on a separate sheet." which isn't available for download....

The only thing it does seem to mention is that a means for disconnection must be provided.

I personally would not consider it appropriate for a 3300W device (13.75A even at 240V ) to be put on a 13A fused spur, Many fused spurs will simply melt if run at anywhere near their full potential for any length of time. Personally I'd put that on a 20A DP switch usually from a 20A breaker if newly installing, and in this case I'd just re-use the existing wiring and connect straight to the cooker point.

It's also not clear whether either oven comes with a flex, but anything of 2.5mm flex or bigger would be likely to cope with the fault on a 32A MCB in any case.

If an electrician will be doing it anyway they could run the calcs and confirm - or just use 4mm or 6mm flex to the oven if necessary to ensure the cable is protected.

It would be interesting to contact HiSense and ask them why their two ovens, with apparently the same rating in kW, are stated as requiring different installation methods.

I wouldn't be surprised if these are 'converted' instructions from european market models, where 15A single circuits are often the most common it seems...

 

[Mark armitage]

I simplified my post for a DIYer. I'm fully aware that you can get MCBs in almost any rating you want, but the chances of the OP finding anything other than 6, 16, 20 and 32 in the range in question, available, and suitable for fitting in his CU, are negligible.
Of more concern is manufacturer's instructions for a 3.3kW @ 230volt appliance to be fed through a 13Afuse. 3.3kW @ 230v = 14.35A

So in this case I should go against the manufacturers instructions and get a 16a MCB and go straight into oven from cooker plate connection and not use 13amp fuse spur. Would this be ok if oven was supplied with 1.5mm cable considering all other cable is 6mm upto cooker plate or should I get electrician to put thicker cable if this is case

I simplified my post for a DIYer. I'm fully aware that you can get MCBs in almost any rating you want, but the chances of the OP finding anything other than 6, 16, 20 and 32 in the range in question, available, and suitable for fitting in his CU, are negligible.
Of more concern is manufacturer's instructions for a 3.3kW @ 230volt appliance to be fed through a 13Afuse. 3.3kW @ 230v = 14.35A

Thanks so on this occasion would you go against manufacturers Instructions and not use a 13amp fuse spur and just get electrician to wire cable straight into cooker outlet. If the oven cable is only thin for 13amp would that be ok considering all other cables are 6mm or would i need get electrician to put thicker cable from oven to cooker plate or would that not be advised to do that.

 

[brianmoooore]

1.5mm2 H07RN-F cable will be operating right at the limits of its specification when you take into account the ambient temperature it will operate at inside the oven's cabinet, so 2.5mm2 would be preferable.
Another problem that occurs with this imported stuff, is that they are often designed for three phase supplies, and the connecting boxes are really only designed for 1.0mm2 cables.1.5mm2 can be difficult, and 2.5mm2 close to impossible.
If this cooker runs at its stated maximum wattage for any length of time, it will destroy a fused connection unit containing a standard 13A fuse, similar to that found in 13A plugs. Very dubious instructions, that Curry's should be asked to justify.

 

[Mark armitage]

1.5mm2 H07RN-F cable will be operating right at the limits of its specification when you take into account the ambient temperature it will operate at inside the oven's cabinet, so 2.5mm2 would be preferable.
Another problem that occurs with this imported stuff, is that they are often designed for three phase supplies, and the connecting boxes are really only designed for 1.0mm2 cables.1.5mm2 can be difficult, and 2.5mm2 close to impossible.
If this cooker runs at its stated maximum wattage for any length of time, it will destroy a fused connection unit containing a standard 13A fuse, similar to that found in 13A plugs. Very dubious instructions, that Curry's should be asked to justify.

Thanks a electrician is coming to look tomorrow so just wanted check I've got this correct if the cable supplied on oven is any thinner than 2.5mm2 I should ask electrician to change it to 2.5mm2 and get them to wire straight into cooker plate and then change 32MCB for 16amp one if that correct. Will it be ok with 2.5mm2 if rest is 6mm2.?

 

[Mark armitage]

Unfortunately websites are very bad at giving the useful information on ovens/hobs etc.

In this case, the manual for the hisense bsa5221abUK doesn't help either -as it says "Instructions for installation and connection are supplied on a separate sheet." which isn't available for download....

The only thing it does seem to mention is that a means for disconnection must be provided.

I personally would not consider it appropriate for a 3300W device (13.75A even at 240V ) to be put on a 13A fused spur, Many fused spurs will simply melt if run at anywhere near their full potential for any length of time. Personally I'd put that on a 20A DP switch usually from a 20A breaker if newly installing, and in this case I'd just re-use the existing wiring and connect straight to the cooker point.

It's also not clear whether either oven comes with a flex, but anything of 2.5mm flex or bigger would be likely to cope with the fault on a 32A MCB in any case.

If an electrician will be doing it anyway they could run the calcs and confirm - or just use 4mm or 6mm flex to the oven if necessary to ensure the cable is protected.

It would be interesting to contact HiSense and ask them why their two ovens, with apparently the same rating in kW, are stated as requiring different installation methods.

I wouldn't be surprised if these are 'converted' instructions from european market models, where 15A single circuits are often the most common it seems...

I found these on hisense website what I don't understand it's states the 16amp oven needs 13amp power supply and a gas Safe engineer no idea why as it's not gas and the 13amp one doesn't need 13amp power supply.

 

[Dartlec]

I found these on hisense website what I don't understand it's states the 16amp oven needs 13amp power supply and a gas Safe engineer no idea why as it's not gas and the 13amp one doesn't need 13amp power supply.

Yes, I suspect that's just a plain error - quite common sadly - sometimes even the manual that comes with it doesn't clarify things.

I think what you said in your last post was more or less the best option. At least 2.5mm flex (some come with a flex, others don't).

The electrician can make an assessment as to whether changing the MCB to a 16A is required. That will probably depend on the length of the cable, the earthing arrangement, etc.

I assume the Cooker connection unit is less than 3m from where the oven will be? If so, then there should be no problem with going from 6mm to 2.5mm - But if MCB is changed to 16A (there may be a spare one in the board, depending on your setup, so may involve only a quick swap of one wire), then you are covered in any and all circumstances...

 

[Mark armitage]

Yes, I suspect that's just a plain error - quite common sadly - sometimes even the manual that comes with it doesn't clarify things.

I think what you said in your last post was more or less the best option. At least 2.5mm flex (some come with a flex, others don't).

The electrician can make an assessment as to whether changing the MCB to a 16A is required. That will probably depend on the length of the cable, the earthing arrangement, etc.

I assume the Cooker connection unit is less than 3m from where the oven will be? If so, then there should be no problem with going from 6mm to 2.5mm - But if MCB is changed to 16A (there may be a spare one in the board, depending on your setup, so may involve only a quick swap of one wire), then you are covered in any and all circumstances...

Yes at moment cooker connection is behind cooker but we are changing it from a freestanding to built in one so it will still be behind oven but oven will be in built in unit will this be ok or as I best asking electrician to move it to the side in one of the cupboards.