Wiring up an induction hob - wanted to sense check if what I'm doing is correct

[Cupa]

Hi guys,

I have a new induction hob which I'd like to wire in. I have already wired in the oven and grill into the kitchen using a length of 4mm 3 core heat resistant flex and that is working fine.

Back of the hob shows the following diagram:



Based on the above schematic, I plan to wire in as follows:



On the assumption my connections in the image above are ok, next question is do I strip the wires free of these connectors which came with the hob?!



...and wire them in like this, by wrapping each core around the screw and then screwing tight (this is a pic of the way I installed the oven and grill with the 4mm heat proof flex cable)



Thanks in advance!

 

[Cupa]

Oh and I forgot to add - the hob, like the oven and grill, have their own respective supply back to the fuse board, each on a 32a breaker. The oven and grill is rated at 5.9kW, the induction hob is a bit more at 7.4kW.

 

[Wilko]

Hi - the flex they've supplied has crimped on ferrules which are helpful. Don't cut them off . Where will you be connecting it? Pic?

 

[littlespark]

They've made your life easy by stripping the flex and crimping ferrules on the end. They should be used.

However, if the connection box hasn't got enough room for the cable, then that's bad design by the oven manufacturer

 

[Midwest]

Why the two different termination (pics)?

 

[Cupa]

Hi - the flex they've supplied has crimped on ferrules which are helpful. Don't cut them off . Where will you be connecting it? Pic?

Morning Wilko, I'll be connecting it to the cooker plate, which was fitted about a year ago by a qualified sparkie. I believe it is 45a.

They've made your life easy by stripping the flex and crimping ferrules on the end. They should be used.

Ok, I'll have a fiddle and see how they can be secured correctly.

Why the two different termination (pics)?

Sorry for the confusion - the cable that came with the induction hob, is 5 core and has ferrules already on each end.

The oven, which I already installed, didn't come with any cable at all, so I looked at the specs and went and bought 4mm 3 core heatproof flex, which I secured as in that pic above by stripping each core and wrapping it around each bolt before fastening it up and checking it was secure by giving it a good yank.

I was using that as an example of fitting - if I can't use the 5 core with ferrules on the induction hob, I was asking if I can strip them off and attach them in the manner as when I installed the oven.

 

[Wilko]

Keep the ferrules and connect all the conductors through to the cooker connection unit .

 

[Cupa]

Keep the ferrules and connect all the conductors through to the cooker connection unit .

Fine I'll resist the urge to lop them off.

Did I read the schematic correctly in terms of hooking it up (my photos in the initial post)???

 

[Deleted account]

R u wiring them in as single phase or 3phase?

Edit: sorry 2 phase?

 

[telectrix]

on single phase you don't require the black and grey. blue to 4, brown to 3. link 2-3.

 

[Cupa]

on single phase you don't require the black and grey. blue to 4, brown to 3. link 2-3.

With this being a domestic single phase / 230V installation, you're suggesting I just wire in the live, neutral and earth to the hob and the same at the cooker outlet plate end and just forget about the other cables / not wire them in anywhere?

I'm a bit confused because the hob is rated at 7.4kW. I am surprised such a piddly small / thin cable is capable of running the hob at its theoretical full output. This is the cable that was supplied by Bosch and it is a lot thinner than the 4mm heat proof flex 3 core I used to install the oven and grill combo with.

 

[Midwest]

I'd tend to follow the manufacturers instructions if using their supplied final connection lead. Do you have a model number and or instruction manual we can peruse?

 

[Wilko]

on single phase you don't require the black and grey. blue to 4, brown to 3. link 2-3.

Hi - not to disagree, but I think the supplied lead may not have ccc if all conductors are not used as per the wiring diagram.

 

[UNG]

So using the supplied 5 core flex to the cooker plate connect

2 - brown & 3 - black to the live
4 - grey & 5 - blue to the neutral
and green/yellow to earth

 

[telectrix]

Hi - not to disagree, but I think the supplied lead may not have ccc if all conductors are not used as per the wiring diagram.

so they've supplied a cable meant for 2 phase to a customer with a single phase supply?????

 

[davesparks]

on single phase you don't require the black and grey. blue to 4, brown to 3. link 2-3.

No, he needs the grey and black as per the diagram, the brown and blu encores aren't of sufficient CSA for the current, that's why the diagram is shown with the grey/ blue and brown/black paired at the connection plate, not just linked out on the hob terminals.

 

[davesparks]

so they've supplied a cable meant for 2 phase to a customer with a single phase supply?????

Yes, this is fairly common, although the flex is normally pre fitted to the hob rather than being loose.

 

[telectrix]

so to pre-empt Brexit..... ditch the foreign 5 core and fit some goof old British 7/036 3 core in red/black.

edit. good,not goof.

 

[PEG]

No, he needs the grey and black as per the diagram, the brown and blu encores aren't of sufficient CSA for the current, that's why the diagram is shown with the grey/ blue and brown/black paired at the connection plate, not just linked out on the hob terminals.

Yep,neutral is actually linked at both ends,in diagram.

 

[Cupa]

Morning folks!

The hob is a Bosch PIE631FB1E, 7.4kW. I couldn't find a useful manual aside from how to use the thing.


So, I rang Bosch tech support who said the 5 core is the
correct cable to use in the UK and that I should hook the lot up as per schematic N1, as shown on the back of the hob.
Things I'd like to know the answer to if anyone knows:

(a) #1 remains unused for some reason

(b) #4 + #5 are linked if you look carefully whereas #2 + #3 are not?!



(c) appliance has a sticker rating of 7.4kW, the cable is much thinner than the 4mm 3 core heatproof flex I hooked the oven and grill up with. Is this due to the diversity factor?

Thank you for the ongoing help guys, appreciate it.

 

[Bobster]

a) probably a generic molding used for multiple appliances, or even a three phase version.

b) 2 and 3 could be wired as separate phases, this is why they are kept separate from the factory. The neutral is always linked.

c)You are using 2 x what looks like 2.5mm for both the "live" and neutral so in effect 5mm.

Put some brown heat shrink or tape over the black on both ends, and put some blue heat shrink or tape over the grey wire to identify that they are being used for the same thing.

 

[Cupa]

Thanks Rob! I bought a new heat gun about six months ago and have been itching to use it, so will crack open the shrink wrap assortment and get that done.

 

[Cupa]

Hello guys just wanted to give a quick update - here is how I wired the induction hob in (pic attached).

At the cooker outlet plate end, I applied my shrink wrap in pairing up the blue + grey (neutral) and then separately paired up the black + brown (live).

Sadly I don't have a photo of that part because it was only after I finished everything AND put the cover on the cooker outlet plate back on and fitted the kitchen drawers that I realised I didn't do a photo, doh!

Went back to the consumer unit, fired it up and it works a treat.

Thanks to all for your help!

 

[Always learnin]

What an excellent post and series of answers.
I'm replacing an old ceramic job with an almost identical Bosch induction hob to that of the original poster. So finding this post has resolved my query about the cabling BUT the 5 core cable supplied by Bosch with our 7.4kw induction hob is actually marked 1.5mm.

My Question 1..... An assumption was made in one of the answers above that it's "probably 2.5mm" so I'm naturally concerned that my 2*1.5mm (3mm) cables will be right on the limit for my 7.4kw Bosch induction hob.
My Question 2.......The length of exposed cables from the outer sheath to the crimped ends is 7cm. This seems to me a bit long to be of much use? The crimped ends will be great to connect into the cooker outlet screws, but will mean that the sheathed section is outside the cable gripper.
Any suggestions or advice will be gratefully received.