5 core induction hob cable (1.5mm?) to 10mm supplied cooker outlet

[BobT007]

Hi,
bit confused.
10mm2 cable runs from consumer unit (32Amp MCB) all the way through to cooker outlet plate (via cooker control unit).
New induction hob is supplied with 5 core cable (2L2N1E), which apparently has 1.5mm2 conductors (has 5G1.5mm2 on cable), to be connected to the outlet plate.
Hob is rated 7.4kW.

Cooker outlet plate info says use conductors of same c.s.a (CSA cross-sectional area).

So how does that work, if the hob cable to use has conductors with much less CSA than the supply cable coming into the outlet plate?

Thanks,

 

[pete01]

The supply cable is too big (oversized)...probably

Edit, thats not a bad thing, but 4mm might have been enough.

 

[BobT007]

Perhaps, but if the supply cable is already there, what would be the appropriate thing to do? Just use the official hob cable (which obviously must be suitable to feed the 7.4kW hob), even if it has much lower CSA conductors??

 

[endecotp]

New induction hob is supplied with 5 core cable (2L2N1E), which apparently has 1.5mm2 conductors (has 5G1.5mm2 on cable), to be connected to the outlet plate.
Hob is rated 7.4kW.

Often cookers have the possibility of being connected to a 3-phase supply, which would require 3 lives, a neutral and an earth.

Are you sure yours has 2 lives and 2 neutrals? If so, maybe they’re using the same cable for the 3–phase and the single-phase versions. (Has anyone else ever seen this? What hob is it?)

Cooker outlet plate info says use conductors of same c.s.a (CSA cross-sectional area).

Ignore that and connect what you have, assuming that it fits in the terminals OK.

 

[pete01]

Im not saying change the feed cable it's there now, nothing wrong with oversized.

Yes use the cable that comes with the hob, your hob works out to about 17 amps, the cable is 2 x 1.5mm which is plenty.

 

[JohnW2]

Perhaps, but if the supply cable is already there, what would be the appropriate thing to do? Just use the official hob cable (which obviously must be suitable to feed the 7.4kW hob), even if it has much lower CSA conductors??

Sure, use what it comes with - which, as you say, presumably (hopefully!) has an adequate CSA to feed the hob (which I'm sure it will have). The higher CSA of the upstream cable (which, as has been said, is almost certainly far bigger than necessary) doesn't alter the adequacy of hob cable.

 

[SUNRAY]

Often cookers have the possibility of being connected to a 3-phase supply, which would require 3 lives, a neutral and an earth.

Are you sure yours has 2 lives and 2 neutrals? If so, maybe they’re using the same cable for the 3–phase and the single-phase versions. (Has anyone else ever seen this? What hob is it?)

The only cooking appliance I've encountered with a 5 core flex was without doubt configured for 3phase and some internal alteration was required to beef up the neutral however IIRC it was a 20KW Alexa on 4mm²

Ignore that and connect what you have, assuming that it fits in the terminals OK.

 

[AndyPRK]

OP. I know it sounds crazy! But just connect it up. It’s common for hobs to come with 5 or 6 core flex. As said, made for Euro spec, but can also be used in UK.

 

[pete01]

Op. I know it sounds crazy! But just connect it up. It’s

That sounds crazy

 

[Ragnar_AT]

Continental hobs are usually set up for two phases and have two neutrals in a single ferrule. If you‘re in the Netherlands you split the neutrals, if you only have 1 phase you connect the two lives together. If the hob is supplied without a lead it comes with jumpers in the terminal box that do exactly the same as connecting the two lives of the lead together.

 

[EFLImpudence]

Perhaps, but if the supply cable is already there, what would be the appropriate thing to do?

The 32A of the MCB is the relevant factor.

A huge cable makes no difference.

 

[BobT007]

What hob is it?

It's a Bosch PIE631BB5E.

Thanks for replies so far, very helpful.

Here is more info on that 5 core cable...

Cable / terminals at hob / circuit diagram:

 

[endecotp]

All fine. Just use the cable.

 

[EFLImpudence]

 

[fixitflav]

Im not saying change the feed cable it's there now, nothing wrong with oversized.

Yes use the cable that comes with the hob, your hob works out to about 17 amps, the cable is 2 x 1.5mm which is plenty.

According to a chart I have, 1.5mm is good for 17.5 amp, so OK, but what am I missing? Why have 2 live (and 2 neutral) wires? I assume they're commoned at the 10mm cable, but why not just use one 3-core, 1.5mm at a pinch, preferably 2.5mm?