Cooker Connectionsin Worcester

Diversity, and why the badge rating misleads

A range cooker can carry a rating plate saying eleven kilowatts, which at two hundred and thirty volts is roughly forty-eight amps. Wire it for forty-eight amps and you are paying for cable nobody needs, because every element and every ring never comes on together and stays on. The wiring regulations allow diversity to be applied: the standard domestic calculation takes the first ten amps of the rated current in full, adds thirty per cent of the remainder, and adds five amps more if a socket is built into the cooker control unit. That eleven-kilowatt range comes out around twenty-one amps, which a thirty-two amp circuit in six millimetre cable carries comfortably.

Induction is where that reasoning starts to bend. An induction hob reaches full power almost instantly and holds it, so the assumption behind diversity, that the load is spread out in time, is weaker. A large induction hob paired with a double oven on one existing circuit is the combination worth checking properly rather than assuming, and it is the one that most often turns a simple connection into a new circuit.

Then the practical side. The isolation switch belongs above the worktop and to the side, reachable without leaning over a hot hob, and not directly above it. A built-under oven and a separate hob can often share one circuit, connected through a cooker connection unit behind the appliance so the flex is not carrying the load back to the switch. Many ovens now come with a plug fitted and a rating low enough to run from a socket, which is legitimate if the socket and the circuit behind it are sound, and not if the socket is a twenty-year-old spur behind the units.

Paperwork: connecting a cooker to a suitable existing circuit is not notifiable in England. Running a new circuit for it is, wherever it goes. If your board has no spare way or no RCD protection, that new circuit turns into a board conversation first, and it is better to have it before the kitchen fitter is standing in your hall.

What a cooker connection includes

Checked against the rating plate before anything is priced.

• Rating plate read and diversity applied, rather than guessed
• Existing circuit tested for capacity and condition before reuse
• New circuit run and protected where the existing one will not do
• Isolation switch beside the appliance, not above the hob
• Cooker connection unit behind the appliance where appropriate
• Hob and oven combinations calculated together, not separately
• Tested, certificate issued and notified where a new circuit is involved

How it runs

Send the rating plate

A photo of the appliance label and your board settles most of this without a visit.

Check the circuit

What is there now, what it is protected by, and whether it carries the new load.

Connect or run new

Connected to the existing circuit, or a new one run, priced before either starts.

Test

Tested, the certificate issued, and notified if a new circuit was needed.

Cooker connections across Worcester and Worcestershire

Worcester, Droitwich Spa, Malvern, Pershore, Evesham and Stratford-upon-Avon. Most of these come with a refit, which is kitchen electrics. Where a new circuit is needed and the board is full or unprotected, that is a board upgrade first, and we will tell you that before the fitter arrives rather than on the day.

Why diversity means the cable is smaller than the rating

A cooker's rating plate is the sum of everything switched on at once: every ring, both ovens and the grill. Nothing cooks like that. The wiring regulations allow for it with a diversity calculation, which takes the first ten amps of the rated current in full, adds thirty per cent of the remainder, and adds five amps if the control unit has a socket in it. A cooker with a 40A rating plate therefore works out nearer 20A of design current, which is why a 6mm cable on a 32A breaker is normal and correct rather than undersized. It also explains why swapping a single oven for a range can change the answer: the calculation moves, and the existing circuit may or may not still suit it. That is the check we do before quoting, and it is the one most often skipped.

Cooker installation: what has to be there before the appliance arrives

A cooker installation is mostly decided before anyone opens the box. The circuit has to suit the appliance after diversity, the isolation switch has to be reachable but not over the hob, and the outlet plate has to be positioned so the cable reaches without strain when the cooker is pushed back. Induction hobs are the ones that catch people out: they draw more than the ceramic hob they replaced, and a circuit that was fine for two decades may not be any more. Send us the rating plate and we will tell you before delivery day rather than after.