Garage electrics - new light and additional sockets

[Smiffy7]

Hi,

I am looking to spruce up my single garage, and as part of that, make some additions to the electrics. I would like some guidance please on best methods, duty ratings, fittings etc etc

Existing lighting:
I have a single wire feed (spur?) coming from the house which is off the GF lighting ring main. This feed goes into a junction box with one feed going to the wall mounted switch, and the other going to the pendant light. This is currently fitted with a 100W (equivalent) compact fluorecent light bulb, which in all honesty is rather pathetic and useless for working on a car after dark.

Proposed Lighting:
Quite simply, I would like to upgrade the pendant light fitting. I'm thinking some sort of brighter strip lighting would be better. What would people recommend in terms of single or double tube, rating of fitting, and do I keep with a single light fitting or add a second? A 2nd light is perhaps overkill, but if I do want to add an extra light, how is best to wire it into the existing circuit?

Existing power:
I have a single wire feed (spur?) coming from the house which is off the GF ring main. This feed goes straight into a double socket fitted halfway along the length of the garage. When we moved into the house a couple years ago, I fitted 2no. external PIR security lights the the front and back of the house. To do this, I broke into the side of the double socket and wired in a fused switch. From there I took the feed up to a junction box and took two spurs from this to each of the security lights.

Proposed power:
I would like to add an additional double socket at the back of the garage adjacent to the work bench area. They will be used for power tools, desk lamp, radio etc. I am also considering another additional socket at the back for a tumble dryer. Just in terms adding the sockets, and forgetting about the tumble dryer for now, would I be right in thinking that the best way to do this would be to add a 3 way junction box (rating??) between the existing socket and the house, and from there, taking the feed to the back of the garage, fit another 3 way junction box to make 2 additional spurs to each of the additional sockets?

So back to the tumble dryer, what implications would running a tumble dryer from one of the new sockets have on the proposed electrics?

Many thanks in advance.

 

[ban-all-sheds]

If you fit fluorescent lights, make sure they have high frequency ballasts for safety when working on or with rotating machinery (like car engines, bench grinders etc).

Re sockets - is the existing spur from the house fused?

 

[Smiffy7]

Thanks!

Any advice on whether I should go for a single or double tube fitting? Or even fit two strip lights? What rating would be sufficient do you think?

I'm not sure if the existing socket spur is fused. Where is the most likely place the fuse will be? As far as a can tell it is just a standard double socket with a cable which disappears into the house. I haven't traced the route once is goes into the house.

 

[stillp]

My garage is a double, about 14' x 24'. I have 4 single 5' 58 W HF pop packs (these: https://www.tlc-direct.co.uk/Products/TNPP158HF.html), together with Anglepoise work lights over the benches.

Why do you want to use so many junction boxes? They're just something else to go wrong, which is why the regs require inaccessible JBs to be "maintenance-free". Much better to extend the ring, or take spurs from existing accessories.

 

[oldbutnotdead]

Presumably your garage is attached to the house? (if not there's a sack load of stuff to consider)

Lighting wise for a single garage (usual 8' ceiling height) I'd have a minimum of 4' double fluorescent (or 2 singles) and paint the ceiling and walls white.

Power- you really need to check the power supply situation before you go much further. You say there's a single cable coming from the ground floor ring final- do you know that for a fact or is it just an assumption? Are the ground floor sockets actually on a ring final or is it a radial circuit? Is there any RCD protection on the circuit?

Assuming the single cable IS connected to a ring final and IS 2.5mm T & E and ISN'T running through a load of insulation or 25 metres down the garden then the single double socket is compliant (that looks silly but it is what I mean). If you want more than 1 socket on that spur from the house then you need an FCU on the single cable between the house and the plethora of sockets to maintain compliance. From the FCU just daisychain 2.5mm T & E to all your sockets (no point forming a ring, the biggest fuse you can put in the FCU is 13A) and the FCU supplying the security lights. You might want to think about mechanical protection for the cable (plastic 20mm conduit will do for a single run of 2.5mm) since the cable will be on the surface and there's scope for heavy metal things to hit it.

Power wise if the tumble dryer is running there won't be much spare capacity- your radio, anglepoise, small electric drill etc will be OK, if you put the kettle on at the same time you'll do the fuse in the FCU. Make sure you vent the dryer to outside (unless it is one of those posh condensing ones)

 

[ban-all-sheds]

There are definitely assumptions and uneducated guesses going on:

... the GF lighting ring main ...

 

[securespark]

I have a slightly smaller garage to yours stillp (11 x 20), and I have two 8 foot twins that light the place very well. I only used them because they were going begging from a warehouse conversion I was doing.

As far as the load on the sockets is concerned, you really need to ascertain where the supply comes from and what it is rated at.

Chances are it is via a 13A FCU (if not and it is spurred off a socket outlet, it should be fused down), in which case that is your load limit.

If by some lucky chance it is connected at the board, you could wire it onto its own breaker (20 or 25A, assuming 2.5 cable) which will give you more scope.

 

[Smiffy7]

Presumably your garage is attached to the house? (if not there's a sack load of stuff to consider)

Yes, garage is attached

Lighting wise for a single garage (usual 8' ceiling height) I'd have a minimum of 4' double fluorescent (or 2 singles) and paint the ceiling and walls white.

So maybe I'll get a 5" double like this, together with a pair of "White" tubes like these (or would "daylight" tubes be better?) and also one of those downward deflectors - I am painting the walls white but I have no ceiling. This set up should be a significant improvement to my single stick fluorescent pendent bulb?

Power- you really need to check the power supply situation before you go much further. You say there's a single cable coming from the ground floor ring final- do you know that for a fact or is it just an assumption? Are the ground floor sockets actually on a ring final or is it a radial circuit? Is there any RCD protection on the circuit?

All I know for certain is that both the existing socket and existing light each have is a single cable feed coming from the house. The socket feed looks to be 2.5mm T&E and the light feed 1.5mm T&E. My consumer unit has 4 breaker switches: GF lights; FF lights; GF sockets; FF sockets. When I switch of GF sockets it cuts power to the garage socket and when I switch of GF lights it cuts power to the garage light. I'm afraid my electrical knowledge is exceeded when it comes to determining ring final/radial circuit or RCD protection - apologies.

Assuming the single cable IS connected to a ring final and IS 2.5mm T & E and ISN'T running through a load of insulation or 25 metres down the garden then the single double socket is compliant (that looks silly but it is what I mean). If you want more than 1 socket on that spur from the house then you need an FCU on the single cable between the house and the plethora of sockets to maintain compliance. From the FCU just daisychain 2.5mm T & E to all your sockets (no point forming a ring, the biggest fuse you can put in the FCU is 13A) and the FCU supplying the security lights. You might want to think about mechanical protection for the cable (plastic 20mm conduit will do for a single run of 2.5mm) since the cable will be on the surface and there's scope for heavy metal things to hit it.

So I think I should be OK with this suggestion by the sounds of it then. So I just need to fit an FSU (would 13A like this be OK?) between existing socket no1 and house, then run some 2.5mm T&E between existing socket no1 and new socket no2, then another run of 2.5mm T&E between socket no2 and socket no3, and so on until the cable stops at the final socket?

Just to clarify the wiring to my existing security lights, I have taken a spur from the side of the existing socket to an adjacent fused switch (not FSU) and then used 1.5mm T&E from the fused switch to the lights. Is this OK as it is? It will mean that I will then have 3 lots of cables going into each terminal of the existing socket - could be rather tight?

Power wise if the tumble dryer is running there won't be much spare capacity- your radio, anglepoise, small electric drill etc will be OK, if you put the kettle on at the same time you'll do the fuse in the FCU. Make sure you vent the dryer to outside (unless it is one of those posh condensing ones)

All advice noted. I think we could manage with coordinating usage of the tumble dryer in reality, but in all honesty it is the wife's idea and I'm not particularly a fan of it being in the man cave. I was kind of hoping you might advise against it as a risk

 

[Smiffy7]

There are definitely assumptions and uneducated guesses going on:

... the GF lighting ring main ...

You would be correct!

 

[securespark]

No, no risk, as everything power-wise in there would be protected by the 13A fuse in the FCU.

More of an inconvenience if things go off.

 

[stillp]

no risk, as everything power-wise in there would be protected by the 13A fuse in the FCU

Which FCU? All we know is:

Existing power:
I have a single wire feed (spur?) coming from the house which is off the GF ring main.

Smiffy, when you say "off the GF ring" is there a FCU there, or is it just connected directly to the ring?

 

[securespark]

So I just need to fit an FSU (would 13A like this be OK?) between existing socket no1 and house, then run some 2.5mm T&E between existing socket no1 and new socket no2, then another run of 2.5mm T&E between socket no2 and socket no3, and so on until the cable stops at the final socket?

I was talking about the proposed FCU.

 

[ban-all-sheds]

would "daylight" tubes be better?

Depends what you like and/or can get used to. Daylight ones are pretty harsh. But tubes don't cost much - get two of each, use the ones you prefer and keep the others to stick in when one fails, while you sort out a replacement.

This set up should be a significant improvement to my single stick fluorescent pendent bulb?

My consumer unit has 4 breaker switches: GF lights; FF lights; GF sockets; FF sockets.

I'm guessing a Wylex standard with plug-in MCBs, and no RCD.

When I switch of GF sockets it cuts power to the garage socket

Which it would do whether there was an FCU or not.

I'm afraid my electrical knowledge is exceeded when it comes to determining ring final/radial circuit or RCD protection - apologies.

Does your CU have a main switch with a button marked "Test"? Is there a separate unit between the meter and the CU with a switch with a button marked "Test"?

If no to both then you have no RCD. As a separate issue you might like to think about getting that remedied....

So I just need to fit an FSU (would 13A like this be OK?) between existing socket no1 and house, then run some 2.5mm T&E between existing socket no1 and new socket no2, then another run of 2.5mm T&E between socket no2 and socket no3, and so on until the cable stops at the final socket?

If you have no RCD, make it an RCD FCU.

It can go in the garage before the sockets, if that's easier, and after it you can use 1.5mm², no need for 2.5mm².

Just to clarify the wiring to my existing security lights, I have taken a spur from the side of the existing socket to an adjacent fused switch (not FSU)

What sort of fused switch have you got which is not a Fused Connection Unit (more common term) aka Fused Spur Unit (less common)?

and then used 1.5mm T&E from the fused switch to the lights. Is this OK as it is? It will mean that I will then have 3 lots of cables going into each terminal of the existing socket - could be rather tight?

Should be absolutely fine. If for any reason you are struggling, take the supply for the security lights from the newly installed socket FCU, then there will be only two in each terminal. But do keep the existing lighting FCU in place - not so much for the fusing as to keep a way to isolate the external lights if they get water in and start tripping the RCD.

I'm not particularly a fan of it being in the man cave. I was kind of hoping you might advise against it as a risk

Sadly no, not electrically.

You could try bigging up the soiling risk of clean clothes in a garage where you are fiddling with greasy things....

 

[oldbutnotdead]

Heh- started a reply & then got distracted, b-a-s has said it all for me .

 

[Smiffy7]

My CU does indeed have a main breaker switch with a "Test" button next to it, so looks like I'm good to go ahead with the install as discussed. Thanks everyone for your invaluable advise.