UK Kitchen grid switch help

[ibra123]

Hello everyone, I'd like to seek your input on a matter. I'm in the process of designing the electrical connections for the following kitchen appliances:

Hob
Oven (below 2kW)
Fridge/Freezer
Dishwasher
Washing machine
Extract Hood

For the hob, I intend to connect it to a cooker connection unit (located below the counter) and then to a 45A cooker unit (above the counter) on a dedicated circuit.

As for the remaining appliances, my plan is to wire them to unswitched 13A sockets (positioned below the counter) and then connect them to a 6-Gang grid switch, which will be part of a 32A ring circuit.

Now, I have concerns about the potential load being too high for a single circuit. Is it possible to establish two separate circuits for the grid switch without the need for an ugly warning notice?

Additionally, I've been pondering whether placing all these appliances on a 32A ring circuit might result in the 13A fuse in the appliance plug blowing first in case of an overcurrent issue. This would require users to remove the appliance and replace the fuse. Any thoughts on this matter?

 

[Dustydazzler]

Most appliances come with a melded on plug top which is recommended stays on as part of the warranty. I try not to cut any plug tops off unless I absolutely have to.
For a multi way grid you can take a couple 20amp radials to the grid to spread the load a bit. just make sure everything is labelled at the board and you can even put some stickers on the back of the grid

 

[ibra123]

Most appliances come with a melded on plug top which is recommended stays on as part of the warranty. I try not to cut any plug tops off unless I absolutely have to.
For a multi way grid you can take a couple 20amp radials to the grid to spread the load a bit. just make sure everything is labelled at the board and you can even put some stickers on the back of the grid

I won't be cutting the plug tops, I will be plugging them to 13A unswitched sockets.

As for the gird switch, BS7671 section 537.1.2 states "Where an installation or an item of equipment or enclosure contains live parts connected to more than one supply, a durable warning notice shall be placed in such a position that any person, before gaining access to live parts, will be warned of the need to isolate those parts from the various supplies unless an interlocking arrangement is provided to isolate all the circuits concerned." This tells me that the warning notice needs to go next to the grid switch.

 

[Dustydazzler]

I guess technically yes

But I put a sticker on the backside of the grid cover plate

 

[DPG]

20A isolator above worktop above each socket - can then have get them engraved with appliance type.

Also saves the congestion of a grid switch.

 

[littlespark]

“Congestion”

That’s a great word to describe what a PITA it is to work in them…. Especially one fitted under a wall unit.

 

[nicebutdim]

Additionally, I've been pondering whether placing all these appliances on a 32A ring circuit might result in the 13A fuse in the appliance plug blowing first in case of an overcurrent issue. This would require users to remove the appliance and replace the fuse. Any thoughts on this matter?

What makes you believe appliance fuses would be affected in these circumstances?

Protective devices at db tripping due to overloaded circuit or cumulative earth leakage would be a greater consideration.

It's not a circuit I'd be happy installing, with the possibility of one appliance fault taking everything else out.

 

[ibra123]

20A isolator above worktop above each socket - can then have get them engraved with appliance type.

Also saves the congestion of a grid switch.

The point is to not have sockets visible above the kitchen worktop.

 

[ibra123]

What makes you believe appliance fuses would be affected in these circumstances?

Protective devices at db tripping due to overloaded circuit or cumulative earth leakage would be a greater consideration.

It's not a circuit I'd be happy installing, with the possibility of one appliance fault taking everything else out.

If I am protecting several appliances that have plugs with 13A fuses and a 32A RCBO ring at the DB, wouldn't the 13A fuse blow first if there was an overload due to one of the appliances?

How would you circuit the above listed appliances?

 

[littlespark]

The point is to not have sockets visible above the kitchen worktop.

You wouldn’t.

The sockets are below the counter. The switches are above. Individual switches rather than a bank of 4 on one plate.

 

[ibra123]

You wouldn’t.

The sockets are below the counter. The switches are above. Individual switches rather than a bank of 4 on one plate.

So you are saying have 4 switches as per below picture (on the right)?

I think a grid switch looks better and takes much less space.

 

[DPG]

So you are saying have 4 switches as per below picture (on the right)?

I think a grid switch looks better and takes much less space.
View attachment 111451

Yes but you wouldn't normally have them in a row like that. You would have one above each socket, so they would be much further apart, and sometimes on different walls.

 

[Dustydazzler]

a 4 gang grid is a neat option especially if you can get the switches with the little writing on saying what does waht

 

[DPG]

a 4 gang grid is a neat option especially if you can get the switches with the little writing on saying what does waht

The trouble is he wants a six gang and with possibly two circuits feeding it.

 

[ibra123]

a 4 gang grid is a neat option especially if you can get the switches with the little writing on saying what does waht

Yes a 6-gang to do oven, fridge, dishwasher, extract hood on a 32A ring, as well as dishwasher on 16A radial (all in the same grid switch)

 

[nicebutdim]

Appliance

If I am protecting several appliances that have plugs with 13A fuses and a 32A RCBO ring at the DB, wouldn't the 13A fuse blow first if there was an overload due to one of the appliances?

How would you circuit the above listed appliances?

The situation you describe applies to an appliance overload regardless of circuit type or rating, but is highly unlikely to occur. Short circuit is more likely and would probably take out circuit protection at board than appliance fuse.

 

[oscar21]

Honestly I don't know why people mess about with grid switches, they must be the hardest thing to fit in a domestic situation, every make I've come across has something stupid about them. The MK ones need a yoke and the switches keep popping out of them, same for other designs, others have screw terminals that are not up to the task of taking two 2.5 cables and most never look entirely straight when you put them on.

We occasionally have to fit them as per a spec and the only one I'll even consider fitting now is a click grid pro one, even the mini grid from click is pants.

So it begs the question as to why people chose them, sockets inside cupboards without any sort of extra isolator anywhere is by far the best bet in my opinion. I remember a Thomas Nagy video where he fitted one and he used a 20A switch marked "HOB" to operate a contactor back near the consumer unit which switched the 6mm to the hob, as if they aren't complicated enough.

 

[Dustydazzler]

I have been doing domestics since the late 1990s and I was under the impression the big ole kitchen grids became popular on new builds because it was cheaper and quicker to fit a single 6 or 9 way grid than to fix a whole load of swi fuse spurs all over the kitchen

that said as above I prefer to fit surface boxes inside units for appliances and keep everything as much as possible out of view

 

[baldelectrician]

I prefer to put a bank of DP switches in a cupboard next to the kitchen (there is usually a tall hall cupboard next to the kitchen)
Other times we put switches in adjacent to the consumer unit- all labelled. A bit more cable, easier to wire and also easier to put different appliances on different circuits.

 

[littlespark]

I was always taught that the isolation switches had to be accessible for emergency’s…. not hidden away in cupboards.

Whether that be on a grid, or all individual.

I believe there’s a Scottish building reg about this that doesn’t exist on the English side??