Electric cooker installation

[JohnW2]

I was giving up hope Nice to meet someone from the real world !

I'm not sure how 'real' it is, but you are presumably talking about "the real world of the regulations" (and, even then, there is discussion about whetherit would be non-compliant). Although I personally wouldn't do it (as I've said, I would use 4mm²), in the "real world of electricity", a 2.5mm² cable supplying a 12kW cooker is not going to come to any harm, regardless of what OPD is protecting it, provided only that the OPD provides adequate fault protection (which will nearly always be the case).

I guess it's therefore a question of what particular 'real world' you're talking about!

Kind Regards, John

 

[EFLImpudence]

Yes. I think the problem was that you did not state that 'they' would also fit a 25A MCB when using 2.5mm

There is a similar thread in another place where it is stated that 10mm² and a 40A MCB would be installed 'to be on the safe side'.

A totally illogical lack of knowledge.

 

[JohnW2]

Yes. I think the problem was that you did not state that 'they' would also fit a 25A MCB when using 2.5mm

It is true that I didn't say that, at least partially because I seriously doubt that a lot of 'them' would!

As I've recently said, it is less clear whether 433.3.1(ii) allows omission of overload protection in the case of a cooking appliance when the cable's CCC is adequate for the after-diversity load (such that a 32A MCB would be fine). The concept of diversity obviously accepts that the the peak instantaneous current may occasionally appreciably exceed the CCC of the cable for short periods - so a 'sensible' approach to 433.3.1(ii) would probably take the same view (i.e. would be thinking about how 'likely' it was that time-averaged current would exceed the CCC of the cable). However, I don't know what is intended.

There is a similar thread in another place where it is stated that 10mm² and a 40A MCB would be installed 'to be on the safe side'. ... A totally illogical lack of knowledge.

Indeed. It's actually not that uncommon for us to hear people talking about 10mm² cable for a cooker. If that were really required, it could well be one of those situations in which it would, strictly speaking, be necessary to get the DNOs permission to install the cooker, since we would be talking about a potential peak demand of about 187A!

Kind Regards, John