changover a new double oven

[rocker]

I am changing over a double oven for a customer..the orginal one is been wired into a spur outlet from the ring main…I feel sure it should run of a radial circuit as the new one is rated at a 30amp load..can ony one confirm this.
john

[Brains]

Re: changover a new double oven

If the oven exceeds 2kW, it is considered best practice to wire it seperately to the Consumer Unit as a radial.

Keep in mind that this sort of wiring work comes under the Part P stuff.

Regards

[rocker]

Re: changover a new double oven

Thanks for reply I thought that may be the case.

[gandh1]

Re: changover a new double oven

in an ideal world all electric ovens and hobs should be on their own dedicated circuit, but reality is like everything nowhere seems to be perfect. Hence best practice… and part P etc

In theory, surely it depends what rating cable has been used for the ring main, how many sockets are on the ring, and what fuse is in the breaker for that circuit, as to whether its necessary to insist on the expense of getting a spark out for it? If certain factors outlined below are ok, then would it not be adequate to connect it under an advisory condition that remedial work is undertaken at the customers earliest convenience?

I say this because a lot of the older installations around here had only a single ring mains on a 30amp circuit, with 3 or 4 fuses on the board max. Feedback from the sparks when weve had them in on these older houses is that as long as the fuse rating is no higher than the cable rating, then it would be just about adequate. The issues you do have with a multitude of sockets/spurs on a single 30amp ring main is if your vac or kettle for whatever reasons goes wack and wants to draw a far higher current then it wont flip out the overload like it would with a 16amp fused circuit, this shouldnt impact on the ovens safety however. Also obviously if theres plenty of high draw appliances on the same ring as the oven the cust will probably eventually get somewhat frustrated when they have the iron kettle toaster oven hob tumble dryer and possible additional heater on at this time of year. Also remember the spur will need to be 30amp rated and you would use 30amp cable from spur to oven even though the double oven is unlikely to draw more than 5kw on full whack. its not worth the risk/grief using 15 or 20amp cable. Also please be aware that just cos you might see 30 amp cable feeding your spur,it doesnt necessarily mean there isnt a lower rating cable inbetween the spur and fusebox.

If you are in any doubt however it really is safer to refuse the install and leave it to the sparks

[rocker]

Re: changover a new double oven

good advice thanks

[Brains]

Re: changover a new double oven

Quote…. ‘In theory, surely it depends what rating cable has been used for the ring main, how many sockets are on the ring, and what fuse is in the breaker for that circuit, as to whether its necessary to insist on the expense of getting a spark out for it? If certain factors outlined below are ok, then would it not be adequate to connect it under an advisory condition that remedial work is undertaken at the customers earliest convenience? ….’ unquote.

This is not correct. Ring final circuits are normally wired in 2.5mm T&E, or in old money, 7/029 in. Other variations (e.g larger cables) are unusual to say the least.

If there is a heavy load on the ring (say in the kitchen e.g washing machine, dishwasher etc) then current hogging can occur on one leg leading to premature failure. UNDER NO CIRCUMSTANCES SHOULD YOU CONNECT a heavy load oven to a ring. No. of sockets do not contol the load by any means.

By all means, advise the customer that an additional radial circuit is required. But, leave the oven disconnected until a new circuit has been installed by a ‘Competent Person’ as defined by Part P.

I’m sure you do not wish to ‘grip the bar’ in the event of an adverse incident.

If you would like further info on current hogging in ring circuits then let me know.

Regards

[rocker]

Re: changover a new double oven

I advised them to call in a sparks who they know, which they did and he as confirmed its ok to use this spur off the ring main, and a 2.5mm cable to feed the oven.
john
(Thanks for advice guys)

[Martin]

Re: changover a new double oven

rocker wrote:I advised them to call in a sparks who they know, which they did and he as confirmed its ok to use this spur off the ring main, and a 2.5mm cable to feed the oven.

…..Errrr? but we’re talking DOUBLE oven here (aren’t we?) and I don’t know of any double oven that is rated at just 13 amps. 😕 Most I’ve ever come across are rated at 30 amps and require a double-poled supply rated at 32amps.

So, next obvious question for you John is : – What is this double oven rated at?

[admin]

changover a new double oven

If their electrician has stated that it’s ok to instal like that then I personally would say let him have the liability as a double oven requires its own 30amp supply.

Bryan

[rocker]

Re: changover a new double oven

Martin, In answer to your question there is no rating plate on this oven, but I beleive it rated around 5400 watts = 22.5 amps. on my calculations I also reckoned this would require a radial circuit, but as stated I advised the customer to check with there sparks to look into running a new circuit circuit, if required, I must admit I was surprised of the outcome.!!
john

[Brains]

Re: changover a new double oven

So, as I stated correctly before then.

I wonder how this is going to work with a 13A spur? I can see a callback and other problems happening with this one. 😯

Regards

[gandh1]

Re: changover a new double oven

Brains wrote: Ring final circuits are normally wired in 2.5mm T&E, or in old money, 7/029 in. Other variations (e.g larger cables) are unusual to say the least.

Fully aware of this, but there are plenty of oddities around here 🙂 Plenty of self-assured “competent” handymen and “i can do it all” builder/developers round here too, and then there are the rogue polish sparkys… (unqualified ones) it makes you wonder how some rewirings ever got signed off 😉

[Author]

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