wiring 4 gang 20a dp grid switches

[bagnall1982]

iv decided to use a grid switch set up for the appliances in my kitchen im going to bring my incoming ring into first switch and then loop in other switches using 2.5mm singles is this considered ok? im goin to run my2.5mm cable then from each dp switch to a single unswitched socket by the location of the appliance. would it be better to have a dedicated circuit for the itchen appliances through the 4 gang switches or is it perfectly fine to have it on the kitchen ring?

thanks Nick

 

[Taylortwocities]

Personally, I would use an 8 way grid with a fuse for each circuit.

I would also run a separate (4mm) 32A radial for the appliances. The approach you are proposing will concentrate all of the loads on to one point on the ring - and that's not good design.


BTW
MK grid 20A switches will handle two 4mm conductors.

 

[bagnall1982]

if i use a 8 way with fuses ill have 2 13a fuses on all the appliances surely this is not needed? with respect to the load all coming from the same place is it not just the same as having 4 sockets in a ring and spuring off each one? or because the load is so close toghter do you think there will be a problem with heat?? i would prefer to run the grid off the kitchen ring as running a new circuit for appliances is going to be a lot of hassle but i would be glad to undertake it if running the grid off the kitchen ring is in someway unsafe?

thanks again

 

[333rocky333]

Not so much the 4 together, more the position round the ring they are, ie quarter round the ring or midpoint, it is bad practise to have say 2met one leg and say 10 met one leg.

 

[bagnall1982]

the ring will have 2 double sockets then the grid then another double socket and bk to the cu

 

[RF Lighting]

Seems reasonable to me.

I personally would not put fuses in the grid.

I think this is another of those times where personal preference and interpretation of the regs comes into play.

 

[333rocky333]

The amount of sockets dont matter, it is the KW load and how it is distributed on the ring with regards to the length of each leg of cable.
See Appendix 15
A small kitchen area proberly not a problem though.

 

[bagnall1982]

thanks for the replys, i have also noticed some disagreement on other forums and post about using 20dp switches on a 32a ring what are your views on this?

 

[333rocky333]

Some say the 20 a switch is not rated to put on a 32 amp circuit, however you are limiting the current to 13a max by using the single socket.

 

[bagnall1982]

this is what i thought rocky but a few posts suggest that the supply side of the switches should be rated to the 32a that the ring is rated too personally im happy with the way im going to carry out the installation now thanks for your help

 

[333rocky333]

It seems quite common now and mk do a range that are labelled up.
However they could be designed for 20amp radial circuits.
There are a few threads on here also, think it is to do with what accesories are allowed on a 32 a ring and whether the 20 a switch is too the same Bs standard.
If you use four 20a circuits, then you get another debate on isolation as there will be four supplies to the said switch.

 

[bagnall1982]

just found this:

In your opinion would you say it is acceptable to install a 20 amp double pole switch in a ring main using the switch to control (switch on and off) e.g. a washing machine or similar appliance via a non fused spur. I mean if the ring was connected into the feed side of the 20 amp switch and the socket into which the appliance was plugged is fed from the load side of the double pole switch?





Yes providing the plug and socket arrangement under counter is fused accordingly.

Also, if you refer to regulation 473-02-02 i, it states that the cable run between isolator and fuse cannot be longer than 3m.

02-10-2006


this was the reply from mk, looks like i might have to think again about putting a 4 gang grid as two of the appliances would need a run greater than 3m, ill get there in the end!

 

[GaryMo]

just found this:

In your opinion would you say it is acceptable to install a 20 amp double pole switch in a ring main using the switch to control (switch on and off) e.g. a washing machine or similar appliance via a non fused spur. I mean if the ring was connected into the feed side of the 20 amp switch and the socket into which the appliance was plugged is fed from the load side of the double pole switch?





Yes providing the plug and socket arrangement under counter is fused accordingly.

Also, if you refer to regulation 473-02-02 i, it states that the cable run between isolator and fuse cannot be longer than 3m.

02-10-2006


this was the reply from mk, looks like i might have to think again about putting a 4 gang grid as two of the appliances would need a run greater than 3m, ill get there in the end!

473-02-02 (16th edition) or more recently 434.2.1 and the reference to 3M is for fault protection - this will be via the MCB in your consumer unit so ignore that.

As long as the 20A switch supplies only one single socket then it will be protected from overload via the BS1362 fuse in the plug top.

 

[bagnall1982]

thanks for that gary ill go ahead with the 4 gang switch then

 

[333rocky333]

One last thing.

Go for as deep box as you can fit , it will make it easier to connect it all up.