Kitchen island power requirement change

[mattleese1988@]

Hi All, first post here and looking for a bit of advice. I am planning on having a few changes done to the kitchen island.

wanting to add a quooker tap.

This is what I currently have in place;
Stating at the CU.

40a mcb > 10mm2 t+e > 60a junction box (at island) > 10mm2 t+e > 45amp mk switch > 7.8kw induction hob.

A few years ago when the extension and kitchen was done I asked for the cable to oversized to accommodate future changes incase we wanted extra hence the 10mm cable.

I have had local spark have a look and this is what he a suggested.

Swap over to a 50a mcb split the cable at the island a take a 10mm feed to a 20a switch and add the tap to this.
The spark has said it's a push getting 2 10mm cables into 60a junction box, he has suggesting using either Henley blocks inside an enclosure or using wago din terminals to split the 10mm cable.

I want to known what's the best option not the easiest or cheapest before I go back.

Any advice is much appreciated

Cheers
Matt

 

[telectrix]

whatever your electrician decides what is viable and safe. can't see much difference in cost with either option. might be beneficial to add a MCB for the tap circuit instead of a 20A switch.

 

[Mike Johnson]

I would put an RCBO on the tap circuit, but whatever your electrician thinks is safe should be OK.

 

[telectrix]

I would put an RCBO on the tap circuit, but whatever your electrician thinks is safe should be OK.

but not if the circuit is already RCD protected.

 

[Mike Johnson]

True, but then I would bypass the RCD and have the whole island on RCBO's, but then I would have the whole house on RCBO's, I am a fan of them. Still no smilies, pretend I put one on with a tongue in cheek.

 

[mattleese1988@]

but not if the circuit is already RCD protected.

Thanks for your replys, I've just been and checked and the board has 2 80a RCDs fitted if this makes any difference?

 

[telectrix]

Thanks for your replys, I've just been and checked and the board has 2 80a RCDs fitted if this makes any difference?

that would indicate that all your circuits are RCD protected. half on each RCD. whichever way your electrician decides to proceed will not make much difference to cost.

 

[Welchyboy1]

Is the hob actually in the island and the sink?

whats the set up ? and where is the 45A switch?is it in a cupboard or on a wall?

 

[mattleese1988@]

Is the hob actually in the island and the sink?

whats the set up ? and where is the 45A switch?is it in a cupboard or on a wall?

Yes hob is in the island and sink also, switch it's at the back of a set of deep draws which I can turn off if I open the draw with hob directly above the draw if that make sense.

 

[Welchyboy1]

Yes hob is in the island and sink also, switch it's at the back of a set of deep draws which I can turn off if I open the draw with hob directly above the draw if that make sense.

cant you just change the 45A isolator switch to one with an additional single socket on the unit and plug the quorker tap into that??

 

[mattleese1988@]

cant you just change the 45A isolator switch to one with an additional single socket on the unit and plug the quorker tap into that??

I asked this is we used to have that type of switch before in old kitchen. But suggested splitting the radial

 

[Welchyboy1]

I asked this is we used to have that type of switch before in old kitchen. But suggested splitting the radial

Sounds like making a simple job hard work to me! why would you do that?

 

[Simon47]

What Welchyboy1 said
The Quooker is only 1.6 or 2.9 (if you get the big one) kW and the instructions say to use a 13A socket.

If you can't just change to a switch with a socket, then just add a single socket as a branch of the radial - it does NOT need to be 10mm cable. Assuming it's only short, then it actually only needs to be 1.5mm to feed a single socket - as the plug is fused, the cable feeding the socket is protected by this fuse and the regs allow for the cable to be smaller than would otherwise be needed for the upstream MCB rating. The biggest problem will be terminating it alongside a 10mm cable into the terminals in the JB.

 

[mattleese1988@]

I'm going to suggest this as the double back box is already in place for the current switch... swap the switch over and Just have to drill a hole for the flex and then put a plug on

 

[Welchyboy1]

I'm going to suggest this as the double back box is already in place for the current switch... swap the switch over and Just have to drill a hole for the flex and then put a plug on

I would insist on it

twin and earth and Henley blocks.........mmmm

 

[mattleese1988@]

I'm going to suggest this as the double back box is already in place for the current switch... swap the switch over and Just have to drill a hole for the flex and then put a plug on

Could he just not come of the 60a terminal block with 2.5mm to a fused spur or single socket ? Looking at the cable would only be half a meter long ?

 

[mattleese1988@]

Could he just not come of the 60a terminal block with 2.5mm to a fused spur or single socket ? Looking at the cable would only be half a meter long ?

I did ask this and he insisted it needs to be 10mm to the socket or spur and this is the cable feeding the island that's when blocks or din terminals was mentioned to split the 10mm into 2. But the switch with socket sounds like this is what I need.

 

[Simon47]

I did ask this and he insisted it needs to be 10mm to the socket or spur and this is the cable feeding the island that's when blocks or din terminals was mentioned to split the 10mm into 2.

Go and find yourself an electrician ;-)
The person you have consulted may call himself that, but he doesn't know what he's talking about.
That's about as polite as I can put it !

 

[mattleese1988@]

Go and find yourself an electrician ;-)
The person you have consulted may call himself that, but he doesn't know what he's talking about.
That's about as polite as I can put it !

I'm going to get someone else to have a look me thinks, I have just spent the last few hours looking through regs and other questions people have been asking regarding similar situations.

As far as I can see taking a spur from the 10mm would be fine providing it has rcd protection, not excessively long and providing the cable has no risk to damage which it hasn't it will be inside the center of the island.

If the tap was to have a fault then the fuse in FSU or plug would protect the cable am I correct ?

By the way the tap is 1.6 kw.

 

[Welchyboy1]

If you upgrade the mcb to 50A(like you previously mentioned), overload protection would be satisfied with a fixed/fused load but maybe fault protection of the cable would come Into play regarding the size of cabling you use between the 10mm and the spur?

what would be the minimum size that could be used?(I’m not sure just hypothesizing)

'no risk of damage' is a bold statement in this game with the muppets that are working in and around it lol!

 

[Simon47]

That would come down to having a suitably low loop impedance so that a fault would still trip the upstream protection. Might have to take the current impedance, add a bit on for the cable being considered, and then do an adiabatic calculation to see if the smaller cable will be OK.

 

[DefyG]

can the switch be changed for a CCU that already incorporates a socket outlet?

 

[littlespark]

can the switch be changed for a CCU that already incorporates a socket outlet?

Already been suggested.

Did I read that the cooker switch is behind drawers?? Not very handy if you need to isolate in an emergency.

 

[DefyG]

Did I read that the cooker switch is behind drawers??

Possibly, I didn't read the other replies properly either that had previously mentioned a CCU.

 

[mattleese1988@]

Already been suggested.

Did I read that the cooker switch is behind drawers?? Not very handy if you need to isolate in an emergency.

Yep it's is no cupboards in island apart from sink. And didn't fancy it been mounted to side panel and risk been dmaged, quite easly get to it just pull draw and switch is their draw is about a foot deep.