Wiring for New Electric Hob - 4 wires

[John White]

Brought a new hob Russell Hobbs (RH60EH402B) because the old one was cracked. New one seems to have four wires, but the old one only had 3. I think I need to pull out the oven to get access to the box that the wires feed into. Do you think I will I be able to connect the new hobs wires easily into this box?

 

[buzzlightyear]

seek a spark .

 

[John White]

You are right of course that probably is the best idea but I really wanted to learn how to do it myself.

 

[John White]

You are right of course that probably is the best idea but I really wanted to learn how to do it myself.

 

[buzzlightyear]

Can you repeat that

 

[Wilko]

Hi John, you've mentioned it has 4 wires so it's possibly set up so the load could be put across 2 phases on low current installations (more common elsewhere in Europe). The instruction manual should have a diagram for you to study, looking a bit like this. But I don't recommend you try "learning by doing" for your first cooker. It's important for safety to get the earth set up correctly to the appliance and prove that it's connected back to your main earth terminal, for example .

 

[littlespark]

Wilko beat me to it. I just found that instruction manual.

Its common with electric hobs to have these extra cables for other electrical systems as suggested.
I've just refitted an existing Beko hob into a new kitchen worktop that has a 6 core flex. Luckily they are all crimped into pairs so I know which is which.

 

[John White]

After spending half a day making the hole bigger in the worktop for the new hob, the thought of unscrewing the oven as well and messing around with that was not appealing. So I thought I would try connecting the old wire that I had disconnected from the old hob into the new hob (silly me)

Switched off the electricity for the whole house,

The new hob has four ports for the wires, Earth, L1, L2 and N.

Connected earth/blue/yellow cable into earth socket, brown into L2 and blue into N as per instruction manual. Manual showed black going into L1 but of course this was the old cable so that one was missing.

Probably not a great idea I know. Anyway the hob powered on, but I could only get heat from the two front rings heated up.

Have I damaged the hob? Would wiring it up properly really be that difficult?

 

[MDJ]

Very likely to be 3 feeds to the hob and a neutral, but it isn't really good practice to attempt it if you are unsure to be honest.

 

[littlespark]

Unscrewing the oven shouldn't be a huge job. 4 screws in the front maybe, and then it slides out the cabinet. Also power off for this.

If it can be unplugged or disconnected, lift it completely out of the way so you can get in to the hob supply cable.

You will need to connect the 4th cable there to bring on the other 2 rings.
DO NOT just bridge across from the brown in L1 to L2. The size of the individual cores of the cable supplied and already connected to the appliance is critical.

Also, did you mean Earth/GREEN/ yellow? not blue

 

[John White]

Thanks littlespark, yes I meant Earth/GREEN/ yellow

Great so I will probably get the oven out tomorrow and have a look at least. If I have to call an electrician at least that part is done.

Good to confirm the hob isn't damaged, thank you.

 

[telectrix]

After spending half a day making the hole bigger in the worktop for the new hob, the thought of unscrewing the oven as well and messing around with that was not appealing. So I thought I would try connecting the old wire that I had disconnected from the old hob into the new hob (silly me)

Switched off the electricity for the whole house,

The new hob has four ports for the wires, Earth, L1, L2 and N.

Connected earth/blue/yellow cable into earth socket, brown into L2 and blue into N as per instruction manual. Manual showed black going into L1 but of course this was the old cable so that one was missing.

Probably not a great idea I know. Anyway the hob powered on, but I could only get heat from the two front rings heated up.

Have I damaged the hob? Would wiring it up properly really be that difficult?

guess that as you have done it is almost right. with the connections as you have said,link L1 to L2, then try that. sounds like L1 feeds 2 rings and L2 feeds the other 2.

 

[littlespark]

Tel... I don't think he should just link L1 and L2 at the hob as the size of the cable may not be adequate to carry all 4 rings.

Replace the 4 core flex as that came supplied with the hob and connect both brown and black to L in the cooker point. (blue to neutral and G/Y to earth)

 

[telectrix]

i should have said, dependent on the ccc of whatever cable is there.

 

[littlespark]

It would probably be ok, Tel.... as the 3 core flex did supply the old hob, but we don't know without seeing it in the flesh.

 

[buzzlightyear]

line /brown .black/line. blue /neutral. green /bang .

 

[John White]

I tried removing the oven today and I could not find the connection point/box for the wires.I think it is behind a cupboard which I cannot seem to get access to without cutting/breaking part of the cupboard.

I think I managed to break the oven as it now turns on but there is no heat so well done to me for that. Fortunately it is really old and several things were already not working with it so was about to replace it anyway, just seems weird that it broke so easily I was very gentle with it.

Is there any safe way of connecting the old wire into the hob so all the rings work? If not, any clues as to how I can get access to the connection box without pulling my kitchen apart?



Picture of Old cable :

old hob cable.png - https://drive.google.com/open?id=1D3DTbCSAzJ9AJqUCllMYYA1vd9LqYqRf

Picture of new cable

new hob cable.jpg - https://drive.google.com/open?id=1I4H3YxhdaaW_FJ-6WM9KDcnSROWkdBdP

Thank you.

 

[buzzlightyear]

I think I managed to break the oven as it now turns on but there is no heat

ho. dear...never mind .you did try .post 2#

 

[John White]

I found the connection box/switch the old 3 wire cable for the hob is connected into :

The front panel switch was loose so I brought a new one (cooker control 45 AMP double pole switch with mains socket) I have wired up the new 4 wire cable into this, no mains connection yet, just did this so I could take a picture of how I think it should be wired so some one could confirm it's correct. You can see the two live cables black and brown/red fed into the L load port on the socket, I think this is what was suggested, does this look ok? :

 

[John White]

Why don't the pictures show?