Grid wiring in a kitchen ring

[Tasty]

Hello for the second time today!I've been asked to install 2, 2 gang switches in a kitchen, which will switch the fixed appliances such as dishwasher etc. Now i've not used modular switches yet but from what I can make out they're pretty straight forward. My question is about integrating them into the kitchen ring, as I was planning on looping in & out much like a socket, then having the appliance wiring drop down from each switch, similar to a spur. However in order to have the switches on the ring, I'm assuming i'll have to bridge between the two individual switches inside each panel. Am I correct in this line of thinking? As always, any replies much appreciated! cheers

 

[Deleted member 26818]

You can wire it as you say, although you will have to use connector blocks for the neutral, and may have to connect four CPCs into one terminal at the grid.
Another way would be to loop into each fuse with the ring line conductors.
Then connect one side of the CPC at the grid, onto the first socket, then to the next and connect the other side of the ring CPC at the second socket.
With the neutral, one side of the ring into the first socket, on to the next and the other side of the ring connected to the second socket.

 

[JUD]

You can wire it as you say, although you will have to use connector blocks for the neutral, and may have to connect four CPCs into one terminal at the grid.
Another way would be to loop into each fuse with the ring line conductors.
Then connect one side of the CPC at the grid, onto the first socket, then to the next and connect the other side of the ring CPC at the second socket.
With the neutral, one side of the ring into the first socket, on to the next and the other side of the ring connected to the second socket.

I think the OP has 4 grid switches (2 x 2 gang). Each 2 gang switch will have 2 separate drops to 1 gang sockets to plug appliances in.

If this is the case then his original way of wiring it up is correct, simply linking switch 1 to switch 2 in each grid.

 

[Tasty]

Ok, I think I follow you, however I'm assuming this is based on using single pole switches. I was hoping to use double pole, meaning no connector blocks for neutral, although I guess I can't avoid the CPC block still

 

[JUD]

Like this...

 

[Deleted member 26818]

JUD, can you show it with the fuses in?

 

[JUD]

JUD, can you show it with the fuses in?

What fuses???

 

[Deleted member 26818]

Is the OP not planning on using fuses with each switch?

 

[JUD]

Is the OP not planning on using fuses with each switch?

There's no need to use fuses as each switch only supplies 1 outlet. Each switch is effectively an unfused switched spur feeding 1 outlet.

 

[Tasty]

Thanks both! My original reply was actually to the SpinLondon, I got you straight away Jud. Thanks for the help. I'm working on my own at the moment, so it really helps to have people to bounce ideas around with!

 

[Deleted member 26818]

There's no need to use fuses as each switch only supplies 1 outlet. Each switch is effectively an unfused switched spur feeding 1 outlet.

Don't know if I like the sound of that.
Normally the device used (when not a grid switch) is an FCU above the counter, with an unswitched single socket beneath the counter.
If as you say (and too be honest I can't actually think of a reason to disagree) fuses are not necessary, then there is no need for an FCU to be used above a counter, a 20A switch would be sufficient.

 

[JUD]

Don't know if I like the sound of that.
Normally the device used (when not a grid switch) is an FCU above the counter, with an unswitched single socket beneath the counter.
If as you say (and too be honest I can't actually think of a reason to disagree) fuses are not necessary, then there is no need for an FCU to be used above a counter, a 20A switch would be sufficient.

What is it you don't like the sound of?

There was a similar thread to this not long ago.

http://www.electriciansforums.net/e...gulations/36758-light-switches-isolators.html

FCUs feeding single socket outlets for appliances are pointless and do not comply with 536.1 because you would have 2 x 13A fuses in series (1 in the FCU and 1 in the plug top of the device) and there would be no discrimination between the 2.

536.1 states that in the event of a fault only the device that is intended to operate should do so.

I assumed the grid switches in the OP are 20A DP switches.

 

[Deleted member 26818]

I'm not sure if I like the sound of it, insofar as it's not the done thing.
However, as you quite rightly say, there is no point in having two 13A fuses in series.

 

[JUD]

If it's not the done thing then why would they bother making these...

 

[Deleted member 26818]

The done thing is usually to install them together with a fuse.

 

[JUD]

However, as you quite rightly say, there is no point in having two 13A fuses in series.

The done thing is usually to install them together with a fuse.

But you don't need a fuse. There's a fuse in the plug top. :banghead:

There's no difference between this and an unfused spur feeding a single outlet (perfectly acceptable) apart from the fact it is switched.

 

[Deleted member 26818]

But you don't need a fuse. There's a fuse in the plug top. :banghead:

There's no difference between this and an unfused spur feeding a single outlet (perfectly acceptable) apart from the fact it is switched.

I know, and I quite agree.
All I'm pointing out, is that the done thing, is to either use an FCU, or a grid switch paired with a fuse.
To be honest with you, showing pictures of switches labeled with appliances doesn't actually mean much, as you can purchase FCUs with the same lables on Buy Crabtree Moulded Fused Connection Unit, Capital, Switched, Single Gang, DP, 13A, w/o Neon, /w Legend - 4827/WM.

 

[JUD]

I know, and I quite agree.
All I'm pointing out, is that the done thing, is to either use an FCU, or a grid switch paired with a fuse.
To be honest with you, showing pictures of switches labeled with appliances doesn't actually mean much, as you can purchase FCUs with the same lables on Buy Crabtree Moulded Fused Connection Unit, Capital, Switched, Single Gang, DP, 13A, w/o Neon, /w Legend - 4827/WM.

Those are meant for direct connection of the appliance to the FCU (no socket outlet).

IMO the only reason for using FCUs with socket outlets is when it is feeding more than 1 outlet so as not to overload the cable.

 

[cliffed]

Its the new damn thing to do now isnt it,all appliances switched from a grid,gud point bout the fuse,must admit sounds a bit odd,also r all switches rated at 32amps,mcb wud be 32amps.Maybe thats y radial circuits may b better than a ring then rated at 16/20 amps hav a gud rainy day ta ra bab

 

[mogga]

IMO if your going to the bother of grids above worktop Id feed to an unfused conection unit under and fit fuse module in the grid as this would save howking the appliance out if fuse goes or put the plugs in next cupboard to appliance for access

 

[JUD]

Its the new damn thing to do now isnt it,all appliances switched from a grid,gud point bout the fuse,must admit sounds a bit odd,also r all switches rated at 32amps,mcb wud be 32amps.Maybe thats y radial circuits may b better than a ring then rated at 16/20 amps hav a gud rainy day ta ra bab

The switches are 20A. However the socket outlet they are feeding (single OR double) is rated at 13A so there's no problem. Think about a socket installed directly on the ring, they aren't rated at 32A are they.

Think of it this way. You can add 1 single or 1 double unfused spur off a ring circuit from a junction box. All you're doing in this case is replacing the junction box with a 20A switch and because the load will never be more than 13A, the 20A switch is more than adequate.

 

[oldtimer]

I had a job at the end of last year where I had to replace switches like this the originals were MEM (no longer made) so I had to replace them with MK but customer was not happy as the cost was not what he expected

 

[andrew692003]

This is really simple and the best way of switching appliances in modern kitchens nowadays. Leaves a neater job and saves having multiple switches around the kitchen. As Jud says linking through the switches and taking one spur down to either a single socket/fused outlet......its that simple. To the OP......a good tip is to use a deep backbox so you have plenty of room for terminating and making a neat job!

Cheers