Switched spurs for the gamesroom

[arcadeuk]

Hi guys,

I have recently had a garage constructed for use as a games room.

I will be getting the electrics done by a competent electrician, however, I would like to know what can and can't be done before getting quotes so that I know exactly what I am asking for.

The games room will contain many arcade machines (video games and pinball etc) This means that getting to wall sockets behind the machines. to turn them on and off would be impossible.

Ideally, what I would like to have is a grid switch plate, near to the consumer unit, fitted with 20amp double pole grid switches, so that I can easily turn each socket on and off from one location.

So basically, power goes from CU to grid switches, then cable goes from each single grid switch, to each single socket located around the games room.

I have seen this done in other peoples games rooms, but they have done this themselves and as such does not necessarily meet regulations.

Is there a way of doing what I am asking above so that the installation meets regulations?

Thanks in advance for your help

Luke

 

[plugwash]

what you propose is absolutely fine. I would use (a) 20A radial circuit(s) from the garage CU to supply the switches.

you need to find out how much power (rememer to use the apparent power (VA) to do your calculations not the real power (W) ) arcade machines draw so you can decide how many it is reasonable to put on a 20A radial circuit and how big the feed from house to garage needs to be. Remember to think about not just the machines you plan to put in initially but also what the loading would be if you swapped machines arround or replaced machines.

For the wiring method I would suggest singles in either dado style trunking or high level PVC trunking with PVC conduit drops to the switches. sheathed cables could be used but are likely to be a pain to terminate at a big grid switch (if you think you will have four switces in about the space of a double socket you can see how wiring space in there could be a bit of a premium and with that much wire arround you want something to manage it and allow easy modifications anyway.

I will warn you now that doing this properly won't be cheap.

 

[arcadeuk]

Hi plugwash,

Thankyou for your very helpful reply.

The average videogame uses 150-200 watts (I've actually measured the consumption of most of my machines at somepoint) . I don't know how to find out or workout the VA (but will google shortly to see if that gives me any help)

I would like to have 16 sockets (so maybe two circuits with 8 each?)

I have various multimeters / clamp meters and one of those plug in energy monitors at my disposal, so can measure anything that I need to measure to work out VA.

When you say singles, I assume you mean the individual wire cores rather than T&E? (which is what is in the trunking in my office)

Are there any regulations you can give me to quote to an electrician (as the only one I have asked so far didn't think I could do what I wanted to do) obviously I am going to shop around to find someone who does know what they are talking about, But I like to know exactly what I am talking about myself, so it is great to get some expert advice from you guys on here.

Thanks again

Luke

 

[plugwash]

to go between VA and watts you need to know the power factor (watts=VA*power factor) which varies from arround 0.5 to 1 depending on the equipment.

8 on a 20A circuit would allow for an average of just over 500VA per machine which sounds sane given your figures. Then a 40A feed from the house CU to the garage CU.

I can't quote any reg numbers but once you look at it this is really not that unconventional. You will find setups not that different to this in many kitchens.

A label will need to be placed to warn those working on the grid switch that it is fed from multiple circuits. This is conventionally placed on the metal grid behind the front plate (I think MK even supply such a label with the grids).

and yes by singles I mean single wire cores designed for mains use. The advantages are they are more flexible (T&E is generally solid core, singles are stranded) and you can use a single earth wire for everything that goes down your run of trunking. I really wouldn't fancy trying to terminate 18 2.5mm T&E cables plus all the link wires between switches in a grid box. The downside is the entire run must be enclosed in conduit or trunking.

I would suggest using RCBOs for RCD protection, they are a bit pricey but given that some of the machines are likely to be old and leaky they are probbally the best option.

so the specs I would give your electrican.

40A feed from non RCD side of house CU to 4 way switch incomer CU in garage. Cable size and type to be selected to be appropriate for length and type of run. If existing supply cable is suitable it should be kept in service.
4 way switch incomer CU with 6A MCB for lighting and 2x20A RCBOs for game machine circuits (and possiblly a third 20A RCBO for non controlled sockets)
18 way grid plus box (or two 8 way boxes if you preffer) to contain switches.
2x game machine circuits to have 8 sockets each controlled by a 20A DP switch module in the grid box.
Game machine circuits to be wired using 2.5mm singles in PVC trunking with a shared 2.5mm earth.
Earthing to be done to high integrity earthing specifications (as is done in offices with lots of IT equipment).

 

[arcadeuk]

Thanks again for your help.

Lots of useful information there.


Kind Regards

Luke