Wiring for 3 Domino Hobs 3/3/3.7kw

[flameport]

While local isolators are not required by the wiring regulations, it's important to remember that BS7671 is the absolute minimum standard required.

If people really want installations which are the absolute minimum required, then good luck with that.

 

[securespark]

I have to agree that regs are the minimum standard. As I've said before, I feel that local isolators can help comply with 314.

 

[winston1]

Tell you what winnie, if you went away, read the regs and understood them, we might be a little less scathing.

But what I have said is correct. There is no requirement in the regs for local isolation for cookers or hobs.

 

[securespark]

There is no requirement for cooker isolation switches in the regs. You can isolate at the CU for maintenance.

You could isolate at the CU for maintenance.
But consider 314.
You could isolate at the CU in the case of fault.
But consider 314.

 

[JohnW2]

I have to agree that regs are the minimum standard. As I've said before, I feel that local isolators can help comply with 314.

I also agree, and personally would certainly favour separate isolators for the OP's three 'hobs' - and also that would achieve quite a lot of the same goals as 314 seeks to achieve.

However, although it may be a bit pedantic, 314 itself is all about 'separation of circuits' in order to achieve those goals, not 'having separate isolators' - and I doubt that you are suggesting that the OP should have separate ('dedicated') circuits for each of his three 'hobs', are you?

Kind Regards, John

 

[SUNRAY]

I doubt that you are suggesting that the OP should have separate ('dedicated') circuits for each of his three 'hobs', are you?

Kind Regards, John

That's what I've suggested but from a dedicated CU.

 

[securespark]

John....no, not separate circuits. In the average installation (in my experience anyway) appliances are more likely to go faulty than the fixed wiring. The ability to isolate appliances without having to isolate huge numbers of circuits at the same time (as you would have to do if you used the main switch or RCD as an isolator is what I'm talking about.

 

[JohnW2]

John....no, not separate circuits. In the average installation (in my experience anyway) appliances are more likely to go faulty than the fixed wiring.

Indeed, and that is a serious understatement - virtually all faults are likely to arise in appliances, rather than the fixed wiring supplying them.

The ability to isolate appliances without having to isolate huge numbers of circuits at the same time (as you would have to do if you used the main switch or RCD as an isolator is what I'm talking about.

As I've said, I totally agee that it's sensible to have local DP isolation for any hard-wired appliance.

A I said, maybe I'm being pedantic, but (since, by BS7671 definition, and isolator does not create 'a circuit') this has nothing to do with the regulation you quoted (314) - which is all about 'separation of circuits'. BS7671 could have included a requirement for isolators (to achieve much the same as 314 seeks to achieve) - but it doesn't.

Kind Regards, John

 

[JohnW2]

That's what I've suggested but from a dedicated CU.

Well, provided that (as you suggested), the dedicated CU had DP MCBs (which are uncommon and, i suspect, not cheap), that would achieve what one wanted, but it's perhaps over-complicated in terms of the way we normally do things in the UK - provided that the appliances did not require external 'fusing down', multiple DP isolators fed from a single supply would be adequate.

Indeed, I suppose one way to do it would to put 3 'main switches' into a 'CU enclosure' and use them as the three isolators!

Kind Regards, John