unusual cooker wiring? or wrong?

[mrmisior]

the existing setup:
32A mcb, 2 x 2.5mm twin & earth cables in parallel (ring final?) from CU to cooker switch (40m length), there is no other sockets or spurs - only the cooker switch, 6mm cable from cooker switch to cooker (<2m lenght)
it is not right, is it? how can I make it right?
also: the mcb is marked 'heater' not 'cooker'...

Michael

 

[sythai]

What is the cooker rated at and how is the cable routed (clipped direct, through 100mm insulation etc)...? :icon3:

Sy

 

[Sickmick]

So you're saying there's a ring main like set up, which only supplies the cooker? No that's not right, you'll need to run a single larger cable probably 6mm depending on conditions.

 

[truckster]

Wouldn't say its wrong, just non standard. As long as the cables follow the same route and are of equal length there is not a problem IMO. Label the board correctly, job done.

 

[dim_bulb]

effectively you have it on a 5mm cable protected by a 32 breaker

I agree with truckster^

werid way of wiring, kitchen fitter?

 

[richy3333]

So you're saying there's a ring main like set up, which only supplies the cooker? No that's not right, you'll need to run a single larger cable probably 6mm depending on conditions.

It might be unusual to do, but why couldn't you run a final ring circuit for a cooker if done correctly? Which Regs prohibit this?

 

[mrmisior]

6kW cooker, 30A max as per manual.
cables clipped on a wooden wall in a ceiling void of 400mmx200mm size, no insulation
my concern is the length of the run ~40 meters
what are the length limits from CU to cooker switch and from switch to cooker? does it apply to this 'ring' or only to proper radial?
wish I would not ask the simple question but can't find answers in the book.

 

[richy3333]

Circuit lengths - Appendix 15 BGB
It's also in the Onsite guide and the OSG for the Building Regs (Sorry cant quote either of these as they are in the van).

 

[telectrix]

as long as volt drop is within limits, no problem. as truckster said. remember diversity. you're looking at a load of around 16-18A.

 

[oxocube]

Seems like a dangerous bodge to me. Parallel cables are usually large sizes that have to be lugged and bolted onto terminals ie impossible for one them to become disconnected. Conversely with 2 x 2.5's its quite likely that a breakage could occur to one 2.5 at a termination point. And your only indication would be when the smoke and flames start.

Should be ripped out and replaced.

 

[telectrix]

Seems like a dangerous bodge to me. Parallel cables are usually large sizes that have to be lugged and bolted onto terminals ie impossible for one them to become disconnected. Conversely with 2 x 2.5's its quite likely that a breakage could occur to one 2.5 at a termination point. And your only indication would be when the smoke and flames start.

Should be ripped out and replaced.

same thing can happen on a ring final, but we still install them.

 

[Adam W]

Fine provided the calcs have been done properly and the cables are installed in accordance with 523.8.

 

[oxocube]

True, but I think the large load of cooker justifies my comment. A domestic ring final is unlikely to be anywhere near full load of 32A.

 

[harristeve]

Sorry this has got to be a rewire

 

[Amp David]

As long as all your tests comply then crack on. Just label the CU up and note on cert.

Chances of conductors breaking once terminated and connection units screwed back is going to be rare, if job done right. If Mr or Mrs bodge it DIYer comes along in the future a fiddles, its there problem.

 

[Amp David]

Sorry this has got to be a rewire

Its ok saying this, but if no ones paying for it, then what you supposed to do?

 

[telectrix]

with diversity applied, the current is generally <20A, so i can't see a problem.

 

[mrmisior]

with diversity applied, the current is generally <20A, so i can't see a problem.

the cooker unit would draw a maximum of 29A when all hobs and both ovens are on (and on maximum power).
in normal use it would be 1 oven and 1-2 hobs ~ 10-15A total.
thank you everyone for answers and suggestions.
cables are terminated at mcb and cooker switch and have plenty of breathing space around.
will leave it as it is.

 

[1shortcircuit]

If the cooker is only drawing the figures in the region that Tel has posted then it sounds fine.

This is nothing more than a spur off of a ring that is supplying nothing else and all the current is being pulled from the centre of the ring. Perhaps the old ring for the kitchen was used to supply the cooker whilst a new ring was installed for a new kitchen installation?

Surely suggesting a rewire of this circuit could only be made on an OPINION because certain sparks wouldn't be happy installing such a circuit in this manner. However, unless you can PROVE that it is unsafe then you can't really enforce the customer having to stick hand in pocket

:thumbsup

 

[acvc]

Sounds like the lazy bleeders ran out of 6mm and couldn't be bothered going for more.