32A cooker circuit

shown73

Sorry if this seems like a daft question, but I am looking at new cookers, and most seem to require a 32A circuit breaker, and appropriate wiring. My present system, which dates form the eighties, has been operating happily with 30A. I notice that B&Q don't even list 30A breakers any more. Would it be ok just to change my 30A for a 32A breaker and carry on as normal? Their is a cooker on/off switch with kettle socket, and the cooker connects into a terminal block at the back of it, with a legnth of cable so that it can be pulled out for cleaning. All standard stuff.
Its a halogen cooker, and I'm looking at replacing it with an induction, free standing cooker, not just a hob. Thanks in advance...

Gloomendoom

My take in this is that the 30 amp breakers are based on a 240 volt UK mains. The 32 amp breaker requirement is based on the 230 volt Euro nonsense standard mains voltage.

Since your cooker will actually be running on 240 volts, there won't be a problem.

shown73

I must admit, I did wonder if it was yet more Euro meddling.

alumende27

For all intents and purposes 30A/32A breakers are interchangeable. Fuses tended to be 30A and (newer) circuit breakers 32A.

What's the power rating of the cooker?

southcoastrgi

Gloomendoom wrote: »

Since your cooker will actually be running on 240 volts, there won't be a problem.

Unless the op's voltage isn't 240 as it can fluctuate

Risteard

Gloomendoom wrote: »

My take in this is that the 30 amp breakers are based on a 240 volt UK mains. The 32 amp breaker requirement is based on the 230 volt Euro nonsense standard mains voltage.

You're completely wrong.

For a start, the voltage is actually 230V (+10%/-6%).

Also, the 30A and 32A ratings have nothing whatsoever to do with the nominal voltage having changed (in 1995 - not any time recently).

Gloomendoom

Risteard wrote: »

You're completely wrong.

For a start, the voltage is actually 230V (+10%/-6%).

Also, the 30A and 32A ratings have nothing whatsoever to do with the nominal voltage having changed (in 1995 - not any time recently).

Maybe you should get yourself a voltmeter and report back when you see 230V -6% at your sockets.

What you and the rest of us are getting is the same 240V ±6% that we got pre 1995. Mine is currently 242V.

Because of the change in 1995 in nominal supply voltage (U0) from 240 V ±6% to 230 V +10% to - 6%, calculating load current from kW or kVA rating is made more difficult. Whilst the nominal voltage was officially changed, the actual range stayed much the same and the actual distributed voltage to homes and other premises remained unchanged. Manufacturers may state equipment ratings at 240 V. In determining current demand from kW or kVA demand, the voltage at which the demand is calculated may be used and this may be 240 V and not 230 V."



exert is from the IET's installation design and calc book.

Risteard

Gloomendoom wrote: »

Maybe you should get yourself a voltmeter and report back when you see 230V -6% at your sockets.

I regularly measure bang on 230V here actually.

What you have failed to realise, however, is that if you measured 242V (assuming that your instrument is accurate) that is 230V +10%/-6% whether you like it or not. How isn't it?

230V +10%/-6% can legitimately vary between 216.2V to 253V and is still a nominal 230V. If you can't fathom this then there really is no hope for you.

stator

If it's connected to a 30A fuse at your consumer unit, then it should be safe shouldn't it?
Your cables and junction boxes or whatever might only be rated for 30A, so the 2A could make a difference even though it's unlikely your oven uses 32A. If the fuse goes then you'll know you need to rewire it up to 32A standard.

Gloomendoom

A standard 30/32A circuit is adequate for domestic cooking appliances up to 15kW.

Just choose a cooker that suits.

There is a chance that the original wiring wasn't to spec, in which case it would be best to check it is 6mm (or possibly 10mm for a long run).

Heedtheadvice

Oh dear blaming the poor Europeans for standardisation!

......but just to add to the technical side....
It does no good to ignore the limits that are binding i.e. 230 +10% -6%
I regularly get on the high side maybe because we live close to a power station but more likely that the solar panel inverter frequently sticks out 252v by design.

Design guidance such as quoted above needs to be read in conjunction with the particular installation situation such as location of and length of cable runs.

So just 'cos 'I get such and such voltage's does not mean we all do!

However the 30A system might well be fine. You just need to consider the max current that might be drawn (cooker power at the highest voltage) and for the wiring that plus your kettle, as well as the wire ratings in it's environment.

If your system is old then it might just be a good opportunity to get it checked prior to cooker installation?