Kitchen appliance switches issue

[mal79]

Hi all,

I am having a new kitchen fitted and am looking for some advice on appliance switches above worktop. I have come to somewhat of an impasse with the electrician regarding this and would like to clarify what can and cant be done.

I would like to have switches above the worktop for the appliances that will be plugged into unswitched sockets below worktop. I am looking for the switches to be contained in a 3 or 4 (3 appliances so far, maybe 4 in future) gang face plate as there will be a double 13A socket outlet next to this. Basically trying to have a means of isolating the appliances but keeping faceplates and sockets to a minimum.

Electrician would instead like to fuse each individual appliance FCU's for each appliance and has chased and fitted back boxes to suit. The only other alternative offered is a grid system with 20A (I think) DP switches and 13A fuses, so 6-8 gang double height grid which is going to look hideous on the wall. Or this can be put in a cupboard, but a) chasing has been done and I will undoubtedly be charged and b) putting in a cupboard defeats the whole point of why I want switches above worktop.

Kitchen sockets circuit will be 2.5 RFC on 32A fuse at CCU. Appliances will have fused plugs on (hence why I want the unswitched sockets) so presumably don't need additional fuse, unless they were to be hard wired. Appliances will be Washer/Drier, Dishwasher, Hydronic Plinth heater (3A).

Electrician says wants to fuse appliance switches individually to protect the cable from burning. I am confused as to what rating the FCU the same as the flex plug protects - the wire between switch and socket? Should RFC be run in 4mm and is that what the reluctance here is?

Electrician tells me he has never seen what I am asking for, yet a quick search seems to indicate this is a common way of doing things just as the in-cupboard solutions seems to be...

Many thanks for any help.

 

[AndyPRK]

I'm not sure I can think of a

I am looking for the switches to be contained in a 3 or 4 (3 appliances so far, maybe 4 in future) gang face plate

Well maybe a light switch, but that wouldn't be upto the job.

I guess a 4 gang grid switch with 20A switches, but I can understand why the electrican would want to fuse them seperatly as they would run off to different places.


As the kitchen ring is rated at 32A amps, electricans like to protect the 2.5mm cable to the appliance socket by fitting switched fused units directly above each appliance socket.

 

[EFLImpudence]

I think you, mal, have the situation completely sussed.

There is no point having a second fuse above the worktop; a 20A switch is fine.
The cable is protected by the fuse in the plug.

If you want to keep the number of accessories above the worktop to the minimum, then don't have any switches.

 

[mal79]

I'm not sure I can think of a

I am looking for the switches to be contained in a 3 or 4 (3 appliances so far, maybe 4 in future) gang face plate

Well maybe a light switch, but that wouldn't be upto the job.

I guess a 4 gang grid switch with 20A switches, but I can understand why the electrican would want to fuse them seperatly as they would run off to different places.

The switches will be more or less directly above the unswitched sockets, as much 3-4 switch face plate can be over 3-4 individual unswitched sockets. The switching order would match the socket order, and appliances next to one another. I can understand if I had requested say double socket spurred off RFC for washer/dryer & dishwasher as that would be overloading the single 2.5mm cable, but each socket will be supplied by indivdual wire. Or am I missing something as to how grid switches work?

As the kitchen ring is rated at 32A amps, electricans like to protect the 2.5mm cable to the appliance socket by fitting switched fused units directly above each appliance socket.

Assuming the appliance is fused at less than the supply cable is rated at, then fuse should blow before cable is overcome? Understand if I am putting multiple 13A appliances on a single 2.5mm as would need to fuse prior to switch in that case, but thats not what I want.

I think you, mal, have the situation completely sussed.

There is no point having a second fuse above the worktop; a 20A switch is fine.
The cable is protected by the fuse in the plug.

If you want to keep the number of accessories above the worktop to the minimum, then don't have any switches.

Lol, that would be remove the current (no pun intended) issue. Do you mean have switched sockets under worktop, like other sockets on RFC?

Having relentlessly looked this up this morning, there does seem to be debate as to whether grid switches on RFC is good practice or not in so far as concentrating load on one leg of RFC, though seems to depend on kitchen size (mine is 4.5x 3m). In this sense, I would have another 2 grid switches on opposite side of room for fridge and extractor, as well as likely be plugging in worktop accessories at various outlets around the room. Is that likely to balance the load?

I expect having a discussion about 4mm RFC is on the cards. And if this electrician doesn't want to do it (part of builders firm doing the rest of work), I will have to find one that will

 

[EFLImpudence]

that would be remove the current (no pun intended) issue. Do you mean have switched sockets under worktop, like other sockets on RFC?

Yes, switches above are a convenience. They are not mandatory.
Additional fuses are unnecessary but if you want switches you can have them.
If you want as few accessories as possible; don't have switches.
It doesn't matter if the sockets are switched or not.

Having relentlessly looked this up this morning, there does seem to be debate as to whether grid switches on RFC is good practice or not in so far as concentrating load on one leg of RFC, though seems to depend on kitchen size (mine is 4.5x 3m). In this sense, I would have another 2 grid switches on opposite side of room for fridge and extractor, as well as likely be plugging in worktop accessories at various outlets around the room. Is that likely to balance the load?

Well, it will help but it is dependent on the positioning on the circuit but is unlikely to be a problem.

I expect having a discussion about 4mm RFC is on the cards. And if this electrician doesn't want to do it (part of builders firm doing the rest of work), I will have to find one that will

If, by RFC, you mean a Ring Final Circuit (it never seems to stand for Radial Final Circuit) then there isn't much point having 4mm².
With 4mm² you could have two Radials, both of which could be 32A.

 

[JohnW2]

I think you, mal, have the situation completely sussed. ... There is no point having a second fuse above the worktop; a 20A switch is fine. ... The cable is protected by the fuse in the plug. ...

I agree.

If what is required is four switches on one faceplace, then I think that grid switches would be the only way to go (but just switches, not fuse modules as well) - and a 4-gang grid plate is the same size as a standard double accessory.

Kind Regards, John

 

[AndyPRK]

It comes back to the problem of the fuse/mcb is there to protect the cable.

So if someone drills though that 2 foot of cable between the switch and socket, the cable rated at 27A will short out, and could burn out before the 32A device. Sounds silly doesn't it.


And yes the ring won't be very ballanced, putting 3 power hungry appliances at the same point, and maybe a 4mm radial would be better.

 

[EFLImpudence]

So if someone drills though that 2 foot of cable between the switch and socket, the cable rated at 27A will short out, and could burn out before the 32A device.

It won't.

 

[JohnW2]

It comes back to the problem of the fuse/mcb is there to protect the cable. So if someone drills though that 2 foot of cable between the switch and socket, the cable rated at 27A will short out, and could burn out before the 32A device. Sounds silly doesn't it.

If there were a 'short', then the OPD would operate long before the cable 'burned out' - and, even if you were talking about a continuous current of 32A (however that came about!), I think 'we all know' that 2.5mm² T+E would come to no harm carrying such a current.

However, I don't think this has got anything to do with the present discussion. If the cable (coming from wherever) went straight to the socket, you (and certainly the regs) would presumably be 'happy' (give or take your comments above!) with that 'unfused spur', so why does inserting a switch into the cable suddenly make you think that there should also be a fuse?

Kind Regards, John

 

[AndyPRK]

Good point! Yeah the MCB would go first.

So why do people like to fit these fused units rather than 20A switch ?

Maybe they are cheaper than 20A switches?

Maybe a 20A switch is considered over engineered and therefore the 13A fused unit is suitable and used.

 

[JohnW2]

Good point! Yeah the MCB would go first. ... So why do people like to fit these fused units rather than 20A switch ? ... Maybe they are cheaper than 20A switches?

Well, if they are being sensible/rational (rather than just 'not thinking') they use switched FCUs only if they want to hard wire the appliances, rather than connect them via a plug (with fuse) and socket. There is no point in having a fuse in an FCU and then another in a plug a couple of feet away!

The argument put forward for doing that (hard-wiring with an FCU) is often that this means that the fuse is accessible in the FCU, and not 'hidden behind the appliance' (in the plug). However, in practice, almost any cause of the fuse blowing would necessitate pulling out the appliance, so I'm not sure it's a very convincing argument/reason

Kind Regards, John

 

[mal79]

So if someone drills though that 2 foot of cable between the switch and socket...

The electrician offered that point which seemed at odds with the original reason as to protect cable from overload from appliances. But there will be the visible safe zone (unlike the "in-cupboard~wall socket" solution), mechanical cable protection and RCD.

Anyway I find out in a couple of days what the electrician's proposed solution is. Thank you for the input guys, it has been very helpful.

 

[JohnW2]

So if someone drills though that 2 foot of cable between the switch and socket...

The electrician offered that point ....

Ask him why it's more likely that someone would drill through the cable downstream of the fuse he wants to install, rather than upstream of it (when his fuse would achieve nothing).

Kind Regards, John

 

[AndyPRK]

You don't get 13A switches without a fuse holders though.

Hardwiring in an appliance is just silly. There are 101 other faults that usually require the appliance to be removed, other than a fuse blowning.

Who wants to be under a work top wiring an appliance in and out, when you could just plug it in.

 

[JohnW2]

You don't get 13A switches without a fuse holders though.

True, but you can get 20A ones easily enough.

Hardwiring in an appliance is just silly. There are 101 other faults that usually require the appliance to be removed, other than a fuse blowning. ... Who wants to be under a work top wiring an appliance in and out, when you could just plug it in.

I personally agree.

Kind Regards, John