Induction Hob and Plug-in Oven connections.

[ExNorthof60]

I just feel the need to check a couple of things and hope somebody can repsond.

My kitchen has a Bosch plug in oven (2.4kw) plugged in to a socket near the oven. This then goes to a fused switch above the worktop with 13amp fuse (switch says Ignition but oven is plugged in).
This is the socket before it was finished. The cooker connection is on its own circuit and the socket is on the same circuit as other sockets in the kitchen (this one is has the wording "Ignition" and is 13amp). Hope I am giving enough info here. This all does look MUCH better than is this picture but is behind oven so I can't take a new photo.
Is it OK that the oven is plugged into this socket with the 13amp fused switch up on the wall?



The kitchen also has a 2 zone Montpellier induction hob 20amp which is hardwired into the cooker connection behind the oven.
Is it fine for hob to be wired into the cooker connection?

 

[ebee]

Something that could run at 2.4KW should not really be plugged in (as a generalisation) was it manufactured with the plug on it? or has someone added it.
Loads 2KW and above should be avoided on a gen socket circuit and be on their own supply.
When you say the hob is 20A how did you get this info? Manufacturers usually state the KW and voltage.
If you know the KW rating of the hob and add it to the oven KW (2.4) you could treat it as a bog standard cooker circuit and make the calculations for a cooker circuit which is less limited because diversity is applied in the calculation.
Although, in practice, a 2,4KW oven is unlikely to run at full whack for excessively long periods it could still run at that for a while at sometimes on a socket circuit that is only rated for 32A sockets total, not a good idea really.

I do note that some Bosch ovens seem to be rated about 2.3/2.4KW and plug in, and if the manufacturer supplies it as such then OK, but personally I`d still avoid it if a single oven.

Sometimes manufacturers add all the single components in differing configurations and give a power output that is impossible, this used to be quite common in some instances (musical industry example) they would add all the outputs together even if many of them could not be used at the same time as some of the others and make out you could get 10KW of sound output with 2KW of power in etc etc, which is impossible. Some used to do such daft descriptions a while back, I`m not sure if they still do.
In this case (music industry example stated above) think of this to be similar to a twin socket with two 5A USB sockets on it, yes you can plug two items in and yes you can draw 5A but that is 5A total (and a bit more) but not 5A each USB socket, 4+1 is OK, 2+3 is OK but not 5+5 or 4+4 or 3 + 3 (actually with 3+3 you`d probably mostly get away with it I would suspect)

 

[EFLImpudence]

If the oven plug is a moulded one then that is presumably how it came and is able to be plugged in to a socket circuit.

You could, of course, connect the socket to the cooker circuit.

 

[ebee]

Exactly correct EFLI , I was waiting for you to make that comment, if the manufacturer allows it then it should be OK but I was, initially, trying to explore the possibility that someone has changed it either by putting a plug on it or ,unlikely, putting a moulded plug and lead on it. And yes I was primarily thinking why not put it on the cooker circuit.

If the OP has the manufacturers instructions that should tell us if it is actually OK in itself plugged in.

 

[ExNorthof60]

Something that could run at 2.4KW should not really be plugged in (as a generalisation) was it manufactured with the plug on it? or has someone added it.
Loads 2KW and above should be avoided on a gen socket circuit and be on their own supply.
When you say the hob is 20A how did you get this info? Manufacturers usually state the KW and voltage.
If you know the KW rating of the hob and add it to the oven KW (2.4) you could treat it as a bog standard cooker circuit and make the calculations for a cooker circuit which is less limited because diversity is applied in the calculation.
Although, in practice, a 2,4KW oven is unlikely to run at full whack for excessively long periods it could still run at that for a while at sometimes on a socket circuit that is only rated for 32A sockets total, not a good idea really.

I do note that some Bosch ovens seem to be rated about 2.3/2.4KW and plug in, and if the manufacturer supplies it as such then OK, but personally I`d still avoid it if a single oven.

Sometimes manufacturers add all the single components in differing configurations and give a power output that is impossible, this used to be quite common in some instances (musical industry example) they would add all the outputs together even if many of them could not be used at the same time as some of the others and make out you could get 10KW of sound output with 2KW of power in etc etc, which is impossible. Some used to do such daft descriptions a while back, I`m not sure if they still do.
In this case (music industry example stated above) think of this to be similar to a twin socket with two 5A USB sockets on it, yes you can plug two items in and yes you can draw 5A but that is 5A total (and a bit more) but not 5A each USB socket, 4+1 is OK, 2+3 is OK but not 5+5 or 4+4 or 3 + 3 (actually with 3+3 you`d probably mostly get away with it I would suspect)

The oven came with the plug attached.

I misread the hob ampage I believe. This is what I have now found. Is this OK to be hardwired into the cooker connection?

 

[Rodders53]

Something that could run at 2.4KW should not really be plugged in (as a generalisation) was it manufactured with the plug on it? or has someone added it.
Loads 2KW and above should be avoided on a gen socket circuit and be on their own supply.

Every washing machine.
Every dishwasher.
Many kettles.
Most fan heater.
Many vacuum cleaners.
Many electric grass cutters.
Every Ninja Airfryer (OK that's perhaps an exaggeration but many are so rated).

None of those appliances run excessively long at full 2.4 kW rating (except perhaps mowers) -- then nor does an oven.
It cycles on/off once at temperature - which with modern ovens does not take very long (10-15 minutes max??).

2.4 kW is only 10 Amps at 240 Volt. It's 3kW appliances that are the bigger issue with plug/socket and 13A final connection units imho.

If the OP has a smart meter they can watch the In Home Display while using the oven etc.,. and see what the appliance consumes.


"Ignition" for the switch/socket implies use for a gas oven or (more likely) hob when the place was built.

To answer the question asked but not answered so far as I can see: The 20A hob connecting direct to the 32A MCB protected cooker supply is usually acceptable as the cable will be protected in the (unlikely) event of a short circuit within it.

If the OP has a smart meter and In Home Display they can see how many extra Watts the home is consuming and for how long when using the oven...

 

[ebee]

OK. Bu I did say " (as a generalisation) in other words things that run for large amounts of time (fan heaters are a prime example) , nowadays I would not like to run more that one at a time on any socket circuit and in any case I personally would avoid even one unless on a dedicated or little additional usage circuit and believe me, not too many years ago there were 3kw fan heaters that were often used in winter, imagine 2 or 3 of them on one circuit, of course we did not use many appliances like today for some of that era.
So, as ones own generalisation but if the manufacturer deems it ok by supplying it then OK, they will have done robust studies etc.
Kitchen sockets do tend to get a bit of stick power wise so might be some advantage of avoiding there too IMHO.

In other words, we do not make a suggestion (rule) then give all the caveats, we give a rule of thumb and hope everybody tries to stick with it mostly because we do not want to add all the complicating ifs and buts so it ends up more like a sweeping statement because sometimes its a good idea to bear in mind.
Plus, sometimes we can actually run things a bit over the top and get away with it quite easily but once this becomes the norm that`s when problems might arise.
Not just in electrics but in other everyday things too.

 

[ericmark]

The appendix 15 does say 2 kW, but the examples are non-portable. The socket seems to be from a dedicated cooker supply, so not really anything to do with ring final rules.

So in theory, if one overloads a correctly designed circuit, some overload device will open, so should be no problem trying it, and seeing how it works, only with the ring final is there a problem.

The ring final has 20 amp cable on a 32 amp supply, so an overload can occur near the origin of the ring, the centre of the ring should be reasonably even load on both legs.

So to stop the problem of potential overload, items using a high load, for a long time, like an immersion heater, should be on a dedicated circuit. The highest and longest load, likely to be plugged into a ring final, is the washer drier or tumble drier, when they use resistive heating. In compassion, an oven of less than 3 kW is a much smaller problem, as although over 2 kW the time the element is powered for is much shorter than the time the element is powered for with a tumble drier.

I have 2 x 3kW kettles on a 4 socket extension lead, not used together now, but I would regularly during the adverts on TV put a cup under each kettle, and make two cups of coffee at the same time, only if we had visitors, and we used them twice in a very short time, would the fuse rupture, as one cup of water is boiled in such a short time. Not used together now, as my battery can supply only 3 kW, so costs less to do one at a time, then two together.

I look at power used. yesterday, the highest was when washing machine, tumble drier, dishwasher, set off before going to bed, and the battery also charging from the off-peak supply. Total 6 kW and in real terms rare we exceed 6 kW, except when having a shower.

 

[ExNorthof60]

Many thanks. I now have my answer

 

[ebee]

Also to note, whilst the modern machines have cut outs/cycling a lot of the older machines did not, many of the older washing machines and dryers are still in existence today, they lasted forever a lot of the old machines they really did and they were rarely replaced if still working, that was the motto of the older generations. Just because it is 10, 20 years old or more is no reason to change it, however old fashioned it is, use it till it breaks, repair it if possible, either yerself of by the fix it expert, only if it`s well beyond that is it replace, I still see some twin tub washers around in use.

Some stuff that was old fashioned when I was young (I`m 69 now) is still in use today, and some folks still have a big galvy tub to fill with hot water, pull clothes out witch big wooden tongues after the "Dolly Blue" pellet had done its job then into the mangle with big handle to crank if your twin tub is at the menders.

It was a different Universe back then but in many ways they had better ideas than today, if something "only" lasts 10 or 15 years it is that cheap modern rubbish them young uns get! LOL.

 

[Rodders53]

OK. But I did say " (as a generalisation) in other words things that run for large amounts of time (f

Collins Dictionary:
A generalization is a statement that seems to be true in most situations or for most people, but that may not be completely true in all cases.

I'd argue that your statement is incorrect.
(Specifically so because many appliances are supplied with moulded on 13A plug top cables and hard-wiring is, therefore, impractical for most.)

My kitchen ring final has:
Aircon Unit (1250 W max)
Washing Machine (2400 W max)
Heat Pump Tumble Dryer (1410 W max)
Breadmaker
Dishwasher (2400 W, max)
Kettle (2400 W)
Toaster
Fridge Freezer
Freezer
Microwave
Plasma TV (185 W average)
Cooker Hood extractor fan
Miscellaneous worktop and room lights, speakers, radios, chargers, etc.,.
Plus small air-fryer, vacuum and steam floor cleaners will be used, plus food mixers and so on.

Only the induction hob, oven and ceiling lights have separate hard-wired circuits.
Only the above and the aircon unit are hard-wired by design.

I'm aware of the limitations... but rarely worry about running my appliances on that circuit at the same time when it is necessary to do so.

Also to note, whilst the modern machines have cut outs/cycling a lot of the older machines did not,

Not a chance on any automatic machine of any age. A manual boiler/copper is not a machine in my book (any more than a pot on an open fire is).

I. too recall the use of tongs to lift out the wet clothes, also the use of a glass washboard.