Hob and Oven wiring help?

[JohnW2]

If they cannot, then should it be considered that the 13A (or16A) is an absolute maximum current that it can handle.

We (at least I) just don't know. In some senses, this could be a side effect of those who believe that OPDs exist only to protect cables. If those who write regulations and Standards, and those who design, manufacture and test accessories think that way, they may not even have considered this issue.

I suppose the first thing (stillp??) would be to ascertain whether BS1363 has anything to say about the ability of plugs/sockets to withstand ('brief') fault and overload currents (i.e. in excess of the 'rated' value).

If so, how would that be ensured when faults occur - or should it always be replaced after such incidents?

Again, as above, we (at least I) just don't know. Routinely replacing accessories after an OPD protecting the circuit would seem rather OTT, but what do you think?

Kind Regards, John

 

[EFLImpudence]

I don't know.

I have always assumed they were made, as with cable, to withstand 'expected' currents.

However, it is apparent, for whatever reason (they may have been damaged or worn out), that some plugs do not cope with 13A for long periods - immersions - but conversely I have seen one on an immersion with a plug in timer which has lasted for many years with no adverse effects.

 

[stillp]

I suppose the first thing (stillp??) would be to ascertain whether BS1363 has anything to say about the ability of plugs/sockets to withstand ('brief') fault and overload currents (i.e. in excess of the 'rated' value).

Well, single socket-outlets have to withstand 14A for between 4 and 8 hours in the temperature-rise test, and in the breaking capacity test a current of 13 x 1.25 A, 10 times. The switch is only tested at 13 A ±0,4 A, but for 15 000 operations. There doesn't seem to be anything else.
Plugs are subjected to the same making and breaking test and heat rise test.
It seems self-evident that both should withstand the current necessary to blow a fuse, but I can't see a test for that.
Interesting that plugs with screwless terminals have a special test in which 14 A ±0,4 A is passed for 60 minutes, then the sample allowed to cool for 60 minutes, repeated a total of 200 times, but there is no similar test for screwed terminals.

 

[JohnW2]

It seems self-evident that both should withstand the current necessary to blow a fuse, but I can't see a test for that.

Many thanks. That's what I rather feared. I suppose that means that, strictly speaking, although, as you say, it is 'self-evident' that plugs/sockets should be able to withstand such a fault/overload current, there is no guarantee that products compliant with BS1363 will necessarily have that capability?

Anecdotally, I've certainly heard claims that a BS1363 plug pin has become welded to the socket receptacle when an OPD has operated as a result of a fault.

Kind Regards, John

 

[JohnW2]

I don't know. I have always assumed they were made, as with cable, to withstand 'expected' currents.

I imagine that nearly all of us have assumed that, but we know what they say about 'assuming', and I think that we are now being forced to 'wonder'!

However, it is apparent, for whatever reason (they may have been damaged or worn out), that some plugs do not cope with 13A for long periods - immersions - but conversely I have seen one on an immersion with a plug in timer which has lasted for many years with no adverse effects.

Agreed, on both counts. However, the situation we are discussing, of currents appreciably more (possibly considerably more) than 13A, for fairly/very brief periods is, of course, a rather different matter, and one cannot really extrapolate to that situation from how they do/don't behave with a continuous 13A current .

Kind Regards, John

 

[EFLImpudence]

Agreed, on both counts. However, the situation we are discussing, of currents appreciably more (possibly considerably more) than 13A, for fairly/very brief periods is, of course, a rather different matter, and one cannot really extrapolate to that situation from how they do/don't behave with a continuous 13A current .

Agreed, but if some can't cope with what is their intended purpose, then it must be impossible to tell what will happen in exceptional circumstances.

 

[JohnW2]

Agreed, but if some can't cope with what is their intended purpose, then it must be impossible to tell what will happen in exceptional circumstances.

Quite so.

However, as has been said an implied, not the least by yourself, if we do not know enough about the accessories to know if it would be safe to use them for a cooker whose after-diversity current draw was just under 13A, we also would not know whether they would be safe under fault conditions on ordinary sockets circuits - which would, in turn, lead to your question as to whether we should replace any accessory which had been subjected to a fault or overload current!

Kind Regards, John

 

[jAYISME]

Yes you can hard wire them to the same place - the place where the cooker is wired - but it won't be a socket and plug.


It is true.

I've bought a dual 45a cooker outlet and also bought a oven which is 2.16kw combined with the 7.2kw hob.

Just to clarify, i am OK running both appliances on the same circuit?. Even if i have 4 rings on and the main oven (its a single oven).

 

[JohnW2]

I've bought a dual 45a cooker outlet and also bought a oven which is 2.16kw combined with the 7.2kw hob. Just to clarify, i am OK running both appliances on the same circuit?. Even if i have 4 rings on and the main oven (its a single oven).

Also to clarify, are you talking about running both these appliances off the same cooker circuit? If so, provided that the circuit is at least 32A (i.e. at least 32A breaker in your CU), and provided that the cable is appropriate to that current (at least 4mm², quite possibly larger) then, yes, you can run both appliances from that one circuit.

Kind Regards, John