Hob/Oven Installation

[MARK POLLITT]

I have just bought a ceramic hob which is rated at 6.6kW (it is to replace a gas hob). We have an existing oven/grill rated at 2.8kw.
The house is new. Behind the oven is a spur from the cooker socket to which the oven is connected and also a 13amp fused spur (which supplies the ignition to the gas hob at the moment).
From what I read here the oven could be run from the 13amp spur and I could then use the cooker spur for the hob. If that all checks out then that's fine but what I don't understand is why, if the oven can be run from a 13amp supply, does it have such a heavy cable (6mm)? Is it because these hobs and ovens can be wired in 'series' so to speak with a link cable from the oven to the hob?
Mark

 

[Steve]

Some people wire the oven up to whatever is available, thinking all cooking appliances have the same rating. This is whats happened here.

Of course, check what supplies this circuit, as your electric hob consumes a lot more than the oven. The 6mm cable is fine, but it might only have a 20 amp device protecting it, due to the oven.

 

[MARK POLLITT]

Crafty
Do you mean that what's happened here is that the the oven installer has used an oversize piece of cable and taken it to the 'cooker' spur when it could in fact have been wired to the 13amp spur?
Mark

 

[Steve]

Crafty
Do you mean that what's happened here is that the the oven installer has used an oversize piece of cable and taken it to the 'cooker' spur when it could in fact have been wired to the 13amp spur?
Mark

The installer has thought "oh a cooking appliance" and put it on the highest rated thing he could find. He was probably a kitchen fitter, therefore not qualified!

 

[MARK POLLITT]

Crafty
And there I was thinking "new house, everything must be Kosher in the wiring department!"As you point out the oven was probably installed by a kitchen fitter (who wasn't even qualified as a kitchen fitter).

Obviously the oven cabling has misled me. I will check the fusing on the 'cooker' spur and connect the new hob to that.
Thanks
Mark

 

[Reynardine]

I will check the fusing on the 'cooker' spur and connect the new hob to that.

I might have misunderstood but wouldn't that mean hanging both the cooker and hob off the 13 amp fuse in the cooker fcu ? If so, you might get away with using the oven and possibly two hob rings but then the third hob ring would make the fuse blow.

Instead how about separating the cooker circuit and hob circuit. The 2kW cooker can stay spurred off the mains. The 6kW hob would have its own dedicated circuit back to the CU.

 

[ltheb]

What are you lot on?! Is this a spur (max rating 13amps) or a radial 'cooker' circuit? There is no way the hob should be connected via a 'spur'.
The oven is rated well below 13amps so is ok on a fused spur, even a 13amp plug top.
If you have a separate 'cooker' circuit, please stop calling it a spur - it's a 'radial' circuit. These are typically wired in 6mm twin & earth with a 45amp rated cooker unit/switch, sometimes with an additional 13amp socket incorporated.
The nominal rating of your 6.6 Kw hob is 28.7 amps, however, applying 'diversity' which is used to calculate the likely load, this comes down to 15.6amps - still too much for a 13amp 'spur.' (if the cooker unit also has a 13amp socket then the load is 20.6 amps)
Check that you do in fact have a dedicated cooker circuit, 6mm, right back to the consumer unit, if so it could be protected either by a 20amp or 32amp circuit breaker, subject to the total load.
Hope this helps.

 

[MARK POLLITT]

OK I think that my terminology is causing confusion here.
To recap, this is a brand new house. There is a cooker switch (big red sucker) on the kitchen wall adjacent to the hob and oven. It extends (under the tiles) about 3 feet to a connection point behind the oven(where the oven is taking it's supply at the moment). Next to this connection point (also behind the oven) is another conection point (not a socket) with a 13amp fuse in it which at the moment carries a feed to the ignition on the gas hob.
I intend to connect the new electric hob to the cooker connection and wire the oven to the 13amp point.
Hope that I have explained my self a little better and that someone could confirm that I'n not going horribly wrong anywhere.
Thanks
Mark

 

[RF Lighting]

Sounds OK to me

 

[megawatt]

Me too ... This has already been answered here ...

//www.diynot.com/forums/viewtopic.php?p=667804#667804

[email protected]

 

[MARK POLLITT]

Thanks for the guidance everyone, much appreciated.
Mark