Cooker Outlet Wire

[ant2781]

Hi Guys,

Is there a limit in distance for a wire from the connection outlet plate to the double oven?

Like most posh kitchen layouts we are looking at putting our double oven which is 4.5kw max on the other side of the kitchen along with other tall units and the integrated fridge/freezer.

The hob is staying were it is.

The 45a double pole switch, near the hob, has under the worktop a dual 45a connection outlet plate which are both currently connected too.

Can I return the oven connection wire from the dual plate back up the wall, across the ceiling and then back down the wall the oven is against to a single 45a connection plate then attach the oven?

Please excuse the poorly altered image. I meant the wire to say oven not hob.

Thanks.

 

[ericmark]

There are two factors limiting cable lengths.
1) The ability to supply enough current to activate the current overload within the set time should there be a short circuit, this entails two measurements line - earth and line - neutral you work by the highest loop impedance recorded.
2) Being able to maintain the voltage within set limits when the design current is being draw, note design current which may be lower than the size of the over load device.
For a 32A load on 6 mm² cable we are looking at around 50 meters maximum to satisfy volt drop. This is why for sockets we use the POSH method port out starboard home, and take it around in a circle referred to as ring final to get the length, as building regulation rules often means cables can't take a direct route, as holes in beams 1/3 to 2/3 along the beam.

So without the meter readings your question can't be answered. Electricians who measure every day what the loop impedance or prospective short circuit current, get a good idea when on the limit, so often realise no where near the limit so fit then test, the latter for the paperwork, but I have made mistakes and had to do the job again with thicker cable, or use a smaller overload.

But design is not as easy as most DIY people seem to think.

 

[securespark]

Is it a solid floor?

 

[JohnW2]

There are two factors limiting cable lengths. ..... For a 32A load on 6 mm² cable we are looking at around 50 meters maximum to satisfy volt drop. .... So without the meter readings your question can't be answered.

Whilst what you say is strictly true, what you don't add is that it is incredibly unlikely that a dedicated cooker circuit in anything approach a standard house would be sufficiently long for either voltage drop or loop impedance to be an issue - even with 4mm² cable, let alone 6mm².

If the OP was asking whether there was any regulatory limit to the length of cable from the existing outlet plate to oven, then the answer to that is clearly 'no'.

For ant2781 ... the length of cable from the current outlet plate to the oven is not relevant - in terms of the issue that eric mentioned, all that matters is the total length of cable from the CU to the oven - and, as I've just said, that will almost certainly not be a problem. Despite what eric says, I think that most electricians would probably 'just use' 6mm² (sometimes 4mm²) cable, even though calculations would usually tell them that 4mm² would suffice.

Kind Regards, John