Connect Cooker - Cable Type

[oliversweb]

I have a new extension built with a new cooker point and now I need to connect the dual fuel cooker. The electric over needs a max 7.4KW and the new consumer unit is about 6m away. I was going to connect it using 2m of 6mm / 45amp cable. Is this correct? (does the rating of the consumer unit / cooker RDC unit effect the cable size/rating?)

Also I have some old 6mm cable that is rated at 35?amp ... could I use this?

 

[Chri5]

What is the fuse rating at the board for the cooker circuit ?

Match the cable size and you will be fine, not sure why you have 6mm TE old rated at 35 amp and new at 45 amp ?

How do you know ?

 

[riveralt]

Also I have some old 6mm cable that is rated at 35?amp ... could I use this?

If it is of the black and red variety then no you should use the harmonised colours - though quite why you shouldn't continue with the colours already there is a little mystery to me.

 

[ban-all-sheds]

The OP is talking about the cable from cooker outlet to appliance - do the regulations apply to that?

And in any event, for fixed wiring there is no reason not to continue the use of old colours if you have the cable available.

In fact, if you can reasonably do so there's quite a strong case to say that the law requires you to use it.

 

[oliversweb]

Thanks all for your replies.

In answer to some of questions;

I went and purchased some 6mm 45amp in preperation to connecting the cooker but then realised I had some 6mm 35amp in the loft so then I was confused as to which one I need to use ... and yes the 6mm 35amp was purchased a long time ago (10 years) and it is white with red/black wires but the 45amp is grey with red/black wires. Also the wiring from the consumer to the outlet is grey with red/black wires.

I never got a chance to check the RDC amp rating for the cooker point but if this is 45+ then use the 45amp cable Y/N?

 

[ban-all-sheds]

It would be more useful if the person who thinks I should not have written the reply I did to explain why.

The OP is talking about the cable from cooker outlet to appliance - do the regulations apply to that?

You could start by explaining why I should not have asked that.

And in any event, for fixed wiring there is no reason not to continue the use of old colours if you have the cable available.

If you disagree with that it would help everyone if you would present a cogent argument against it so that the issue can be discussed properly.

In fact, if you can reasonably do so there's quite a strong case to say that the law requires you to use it.

Ditto.


Or is it, perhaps, that you don't believe that you should act in a helpful way, and that you don't see your role as being one of value to the forum?

 

[ban-all-sheds]

I never got a chance to check the RDC amp rating for the cooker point but if this is 45+ then use the 45amp cable Y/N?

The current carrying capacity of cables depends on how they are installed. Carrying current makes them get hotter, so the ease with which they can get rid of the heat limits the current they can carry - for example a cable completely surrounded by thermal insulation can only manage to carry half the current it could do if it was in free air or clipped to the surface of a brick wall. Other factors that affect it are being bunched with other cables, or running somewhere with a high ambient temperature. In a theoretical (and ludicrously extreme) case of a 6mm² cable bunched with a dozen others, tied to a pipe carrying hot water through a boiler room and the whole lot lagged with 100's of mm of insulation it probably couldn't manage enough for a lighting circuit.

See http://www.tlc-direct.co.uk/Book/4.3.1.htm

6mm² is rated at 47A in free air or surface clipped - the only difference between the cables you have, apart from colour, is the rating the maker has decided to quote on the label. Neither 45A nor 35A is correct no matter what.

You can use either to connect your cooker, it makes no odds. Personally I'd use the new stuff, as that has the same colours that appliance flexes have had for donkeys years, and keep the old coloured cable to use for any modifications to the old fixed wiring if ever needed, but it's a pretty marginal decision.

 

[oliversweb]

Top reply cheers!