Are my ovens installed safely?

[Mc3737]

Hi,

I have query and need some advice.

In 2011 we had a new kitchen, in that kitchen we had 2 ovens fitted, a neff microwave/fan assisted oven and a single oven

The microwave is 3.2kw and installed onto a fixed point and feeds back to a b32 at the cons unit with a red isolation switchnext to microwave.
The single oven is 3.68kw and is on a 13amp plug on the kitchen ring main going back to a b32 at the cons unit

I know this now because the single oven stopped working one day whilst heating up and when i pulled it out the switched on the double socket had faulted and was just springing back so i just plugged into the other socket and it has worked ok since then.

My concern is that the oven shouldnt be on a 13amp plug. Any advice would be appreciated

 

[viewer]

You're right. At 230V then a 3.68Kw oven takes 16A.
It needs to be connected as you describe for the microwave, however, before doing that there is need to confirm that the cable is suitable. A 2.5mm T&E will be OK providing it is not within insulation (there is a forum sticky for checking).

 

[Scoby_Beasley]

But then with diversity taken into account it's the first 10A plus 30% of the remaining 6A (1.8A) giving a total of 11.8A.

I wouldn't have had it on a double socket either, single would be OK though. Appliances over 2KW should have their own supply.

 

[Mc3737]

Nothing else can be plugged in as the socket is behind the built in oven so effectively it has its own socket.

I suppose i am establishing is this going to be a future issue or am i going to have to get sparky to come back chase new cables and and cause unneccessary damage???

 

[flameport]

16A on a 13A plug and socket is obviously not appropriate.

If the microwave and oven are in the same place, the easiest solution is to connect both of them to the same 32A circuit. The flex on the oven may need to be changed to a larger size.

 

[viewer]

Nothing else can be plugged in as the socket is behind the built in oven so effectively it has its own socket.

I suppose i am establishing is this going to be a future issue or am i going to have to get sparky to come back chase new cables and and cause unneccessary damage???

Hold on; just to be sure that I understand. The socket cannot be reached when the oven is in use? Is there any other means of switching off the oven (apart from the CU)? If not, then you do need to rethink or get a professional. It is important with any cooking appliance that it can be safely turned off completely by the user. Reasons obvious. This applies even if the unit is normally left connected with clocks, timers etc working. This will also apply to the microwave.

 

[Mc3737]

That is correct, to isolate the single oven will mean isolating at CU which will isolate all sockets in the house

 

[viewer]

Then it's a no no.
From your description it sounds as if you/your electrician could cut back in the wall, fit a new isolator switch and then a short new heatproof cable to the oven. In case of fire, switch off and run for the door.
Again from your description it sounds as if it is just an oven (because you describe it as fitted) and does not have a hob. If this is the case, you can't take advantage of diversity calculations because for that circuit because whenever the oven is on to heat, it will take the full 16A.
Having said that, a kitchen without a hob would be unusual. Is it part of the fitted oven or separate? If separate does it have an easy to reach main switch?

 

[Mc3737]

We have a separate gas hob with an isolator switch for the electric ignition.

Would it be acceptable to ask the electrician, (who by the way came around yesterday to look at what i was concerned about and said it would be ok because i would be unlikely to use the 32amps of the rated breaker even with the oven and other stuff on) just to take a new cable from the single oven to the already existing fixed point for the microwave oven?

That would be 2 x 16a appliances in one fixed point with 32amp circuit breaker. we do by the way use both ovens together regularly, wouldn't that max out the breaker?

 

[viewer]

Join to the microwave protected by 32A MCB? Yes, that was flameport's suggestion. Hope it's a nice cheap answer and won't destroy too much plasterwork.

 

[viewer]

Sorry, missed second question. Yes, your load would be close to the MCB limit, but the 32A means that the MCB will take that load permanently so shouldn't be a problem. You do have to check that the cable to the microwave is properly sized for 32A. It should be, but then the installer put your oven on a socket, so I wouldn't trust anything that they have done.

 

[Mc3737]

Thanks for the response, i agree im not really happy with what sparky has done but he issued part p cert and if i get him back i want him to rectify with as little damage as possible and also i want to understand what im asking him to do and why

Thanks