Hob wiring question

RobTheBob · Aug 15, 2021

Replacing my hob and found this. Hob (6.4kW) installed on a dedicated 32A circuit, wired with 6mm TE. Five terminals on the hob, two lives and two neutrals have each been bridged with 1.5mm wire. TE cable is wired to one of the lives and one of the neutrals. Is this correct? Thank you

telectrix · Aug 16, 2021

the bridging links are usually flat brass links, fitted by manufacturer. should not be wire. check manual for wiring diagram/s. your fixed wiring supply is correct.

as always. a photo would help.

RobTheBob · Aug 16, 2021

Thank you telectrix for your reply.

Weirdly my new hob didn't come with the brass links
Hopefully you can see the image attached

The hob as new is supplied with 5 core 1.5mm cable

Thank you again.

James · Aug 16, 2021

Put the flex back on it, the crimp lugs have not been terminated properly, looks like plier marks not crimp indentations

the cable is not heat resistant, it probably should be but a check in the manual should confirm.

Avo Mk8 · Aug 16, 2021

I would rather rely on factory crimps on the 5 core 1.5mm flex originally supplied by the manufacturer (with one tag on each terminal, and then appropriately joined remotely), than DIY crimps on 6mm solid conductor cable.

The links in the photo seem to have a factory crimp one end, and a DIY crimp the other, showing the same sort of marks that James mentions above. Could they be made from the flex?

It's most important to use a good quality ratchet crimp tool to make such joints, especially on solid conductors.

James · Aug 16, 2021

Agree with everything above.
if the power was turned off and the cable tugged a little, I would bet the cable comes out of the crimp with ease.

James · Aug 16, 2021

Probably a quick job for a sparky with the correct tools and parts in the van.

I would not suggest a DIY repair on this.

HappyHippyDad · Aug 16, 2021

As above, the crimps on the 6mm twin and earth are dangerous and should be removed. Someone has also used the incorrect crimp for the 2.5mm cpc, it should be blue.
A good quality ratchet crimper needs to be used otherwise the joints will heat up and eventually fail. Worst case scenario is a fire.

Lucien Nunes · Aug 16, 2021

As above, unsiatisfactory crrimping with unsuitable tools and connectors that will likely result in overheating, maybe not now while the copper is clean and bright but in a year or two once it has oxidised. A properly made crimp needs not only to be mechanically attached, but to make a gas-tight cold-weld between cable and terminal.

Mike Johnson · Aug 16, 2021

Look inside the terminal block of your new Hob, you may find the brass links already there, but as others have said, should really be heat proof flex, especially if the hob is above an oven with a cover plate between the two with reflective foil.

littlespark · Aug 16, 2021

Is the photo your new hob or old one?

the new one should have all the bits needed, including a length of appropriate flex, with crimped ends, and any copper links. (Check they’re not in a bag with fixing brackets)

If in doubt, RTFM

RobTheBob · Aug 16, 2021

Thank you all very much for your replies.

So other than the poor crimping on the ferrules, and the lack of heat resistance, the actual wiring is correct?

Thank you again,

James · Aug 16, 2021

RobTheBob said:
Thank you all very much for your replies.

So other than the poor crimping on the ferrules, and the lack of heat resistance, the actual wiring is correct?

Thank you again,

There are no other parts of the actual wiring.

what you should have is a switch above the worktop to turn it on and off.
an appliance outlet at the back of the cupboard space to wire the flex from the hob to.
a suitable specified flex (NOT TWIN AND EARTH) between the wall and the hob
correct termination of all conductors and good quality workmanship throughout.

From what you have shown us, ABSOLUTELY NONE OF THAT HAS BEEN ACHIEVED.

freddo · Aug 16, 2021

That 5 core flex needs to go back on and any linking done at the end of the flex not attached to the hob. The 6.0mm cable will be putting enormous strain on those PCB terminals.