Workshop electrics

[glynster]

Being a beginner I am just setting up my workshop (previously known as the garage). The garage/workshop currently has just a single electrical socket installed and I am guessing that this is a spur from the main house downstairs socket loop since it doesnt have any cable going back out from it to a circuit. My plan is to intercept this socket with an key operated emergency stop so that (I can isolate off the full workshop when I am not in there - and make it safer for kids who might sneak in since they will not be able to turn anything on without a key). My question is this, can I run another 2 or 3 sockets in metal conduit from that first socket? I know technically you should not run extras from a spur but since I am never likely to be running more than one machine at a time (OK with dust extraction 2 max) is it really any worse than running a load of extension leads that all come from a single socket?

Just wondered what experience others have etc

 

[Ed209]

A extension lead is protected by its own fuse


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[Ed209]

If I was you I would consult a electrician for advise you can have a dedicated shed/garage consumer unit fitted with RCD protection and you could site it high or in a lockable cupboard so you could isolate the sockets but leave the lighting circuit working


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[glynster]

I get your point but I have a brand new house RCD installed and each machine is fused - extension leads surely cause more accidents through trips than they save by having an unnecessary fuse. They only need to be fused because they trail across the floor - if that makes sense. Otherwise sockets would be fused - which they aren't.

Ed209, I was considering that but having just paid an electrician 2 grand for house work and observing that he didn't do anything that I wouldn't have done myself my wallet is increasingly tradesman-shy. You're right though - technically that would be best. And like I said, I will only ever be using one machine at a time and they are all hobby machines so it seems like overkill.

 

[Ed209]

I can see your point of logic there, I'm not a electrician myself my understanding of the fuse in extension lead is to protect the cable from melting if overloaded


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[Ed209]

I'm fortunate that my consumer unit is in the garage and I just ran a separate ring main for the garage from that


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[riclepp]

my only concern is that could the added extra units that may or may not all be used at the same time cause an overload and trip out the house electrics and possibly cause damage. I am no electrician, but some hobby machines draw lots of power.

I would get an electrician in for advice to be honest.

 

[kmp]

Hi, not an electrician but have just gone through (last year) a similar situation with a small extension. While the experts will argue for hours about the technicalities the practicality is that extra sockets can be added to a spur as long as that spur is fused and of course the correct cable is used. This fuse limits the total power that the spur can carry so will not run multiple sockets with high power requirements. If a 13 amp fuse is fitted then the combined load on the spur sockets will be a maximum of 13 amps. For our extension a Fused Connection Unit replaced the original single socket and an additional three sockets were wired on a radial circuit. This was acceptable to the local council and met all current electrical requirements.

One "daft" (my opinion only and my interpretation of the discussion between electrician and building inspector) issue with the dreaded Part P that we found was that if the circuit is "hard" wired, ie clipped, trunked etc, then it is considered permanent and must be installed by a "competent" person. However if some cowboy puts a 13 amp plug onto a bit of 2.5mm cable runs it round the skirting to a few sockets that is considered temporary and is not covered by part P. Don't ask me I'm just a mechanical engineer.

I'm not suggesting that this is "good practise" solution just that it was legal - last year.

Keith

 

[Stu_2]

Afternoon Glynster

If you're sure you would have been able to do what your electrician did for £2k, then you should be able to sort your garage out with your eyes shut. If you're not so sure, give this guy a call (as you're in Berks, too). :wink:

He's a good guy.

Cheers
Stu

 

[Hemsby]

Being a beginner I am just setting up my workshop (previously known as the garage). The garage/workshop currently has just a single electrical socket installed and I am guessing that this is a spur from the main house downstairs socket loop since it doesnt have any cable going back out from it to a circuit. My plan is to intercept this socket with an key operated emergency stop so that (I can isolate off the full workshop when I am not in there - and make it safer for kids who might sneak in since they will not be able to turn anything on without a key). My question is this, can I run another 2 or 3 sockets in metal conduit from that first socket? I know technically you should not run extras from a spur but since I am never likely to be running more than one machine at a time (OK with dust extraction 2 max) is it really any worse than running a load of extension leads that all come from a single socket?

Just wondered what experience others have etc

I had the same situation as you, just one socket on a spur from a ring main in the house. My consumer unit has just been renewed so my ring main circuit is protected by a RCD at that unit.

However your spur socket is connected to the house (with a 2.5mm cable) if you replace that with a fused spur box you could then run enough sockets from that, I have 5 Double’s, as long as the spur socket has a 13amp max fuse you will be ok providing the total usage at any one time does not exceed that 13amp allowing for any start up surge. I run a table saw, band saw, planer/thicknesses, M/T machine, pillar drill, 2 mitre saws & dust extractor.

As you require extra security for the supply you could install a lockable switch between the fused spur & the first socket.

Like most I only have 2 hands so the chance of overloading the supply is very remote.

The only point I would make is that strictly speaking any installation in a garage should be done by a qualified electrician.

 

[MMUK]

However your spur socket is connected to the house (with a 2.5mm cable) if you replace that with a fused spur box you could then run enough sockets from that, I have 5 Double’s, as long as the spur socket has a 13amp max fuse you will be ok providing the total usage at any one time does not exceed that 13amp allowing for any start up surge. I run a table saw, band saw, planer/thicknesses, M/T machine, pillar drill, 2 mitre saws & dust extractor.

Sorry Hemsby, not very good advice at all. What you have there is very bad practise, too much potential for overloading considering what else may be on that circuit inside the house. I gather you did this yourself? No qualified electrician worth their salt would complete such a circuit.

Back to the OP - without knowing exactly what else is on the circuit that this socket is spurred off, I wouldn't even consider adding to it. Providing that there is minimal potential on the circuit, you may be able to extend the ring. However I would really recommend that you have a completely independant ring main circuit installed on it's own 32A MCB.

 

[woodfarmer]

However your spur socket is connected to the house (with a 2.5mm cable) if you replace that with a fused spur box you could then run enough sockets from that, I have 5 Double’s, as long as the spur socket has a 13amp max fuse you will be ok providing the total usage at any one time does not exceed that 13amp allowing for any start up surge. I run a table saw, band saw, planer/thicknesses, M/T machine, pillar drill, 2 mitre saws & dust extractor.

Sorry Hemsby, not very good advice at all. What you have there is very bad practise, too much potential for overloading considering what else may be on that circuit inside the house. I gather you did this yourself? No qualified electrician worth their salt would complete such a circuit.

Back to the OP - without knowing exactly what else is on the circuit that this socket is spurred off, I wouldn't even consider adding to it. Providing that there is minimal potential on the circuit, you may be able to extend the ring. However I would really recommend that you have a completely independant ring main circuit installed on it's own 32A MCB.

I have been immersed in French electrics for the last 12 years or so, but I thought in the UK they now don't do ring mains but adopted the French system of all radial sockets???

I rewired the barn by replacing the old overhead 15 amp supply by installing 53 amp armoured cable in a trench, running off a 32 amp RCD, Reason was I bought a 4 kilowatt motored log splitter that took a surprising amount of power when starting. now run a mix of 10, 16 and 20 amp sockets.

Surprising how much faster the saw table 2kw, and air compressor start up since the changeover.

 

[glynster]

Stu, I'm not suggesting that I could have easily done what the electrician did with my eyes shut at all - he did a good job for the money and I was happy with it and he did things I could and would not have tackled. Just that having observed him fit out sockets and lights I realised that it is purely logical and paying £45 an hour plus vat will set me back another £300 to £400 when you factor in fittings - that buys a lot of quality timber.

Thanks for all sharing your experiences. I think I will replace the existing socket with a Fused Connection Unit and then one of these: http://www.ebay.co.uk/itm/261474123155?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 and after that run a few extra double sockets from it in steel conduit. I know I should not make permanent or fixed wiring but it is my intention to remove it before we ever decide to sell the house so I dont see a problem.

 

[Terry - Somerset]

I had a similar issue on garage conversion and replaced two separate existing spur sockets with 13 amp double pole switches feeding approx 4 double sockets each. Max load with all machines on (lathe, bandsaw, drill, extractor, sander, air filter) would exceed 13 amps but I only ever have extractor + one other working at a time (filter which is on all the time draws a trivial current). Sockets are connected with 16 amp twin and earth and cables run in trunking. Looking at the government planning portal it seems that competent DIY should be ok:

You DO NOT need to tell your local authority’s Building Control
Department about:
• repairs, replacements and maintenance work; or
• extra power points or lighting points, or other alterations to existing circuits
(except in a kitchen, bathroom, or outdoors).
If you are not sure about this, or you have any questions, ask your local authority’s
Building Control Department.
All work, whether you need to tell your local authority about it or not, must be done
to the standards in the IEE ‘wiring regulations’.

Rgds

Terry

 

[Dee J]

The main reasons for employing an electrician:
1: Interpret how the existing installation is configured.
2: Test that installation to ensure it is functioning correctly.
3: Design and implement any extension or alteration to that installation to ensure safe legal functioning.
4: Ensure all legal and insurance aspects are covered.
The grunt work of cable chasing and connecting up the bits is just the visible part of the iceberg.
Dee

 

[Hemsby]

Hi, not an electrician but have just gone through (last year) a similar situation with a small extension. While the experts will argue for hours about the technicalities the practicality is that extra sockets can be added to a spur as long as that spur is fused and of course the correct cable is used. This fuse limits the total power that the spur can carry so will not run multiple sockets with high power requirements. If a 13 amp fuse is fitted then the combined load on the spur sockets will be a maximum of 13 amps. For our extension a Fused Connection Unit replaced the original single socket and an additional three sockets were wired on a radial circuit. This was acceptable to the local council and met all current electrical requirements.

One "daft" (my opinion only and my interpretation of the discussion between electrician and building inspector) issue with the dreaded Part P that we found was that if the circuit is "hard" wired, ie clipped, trunked etc, then it is considered permanent and must be installed by a "competent" person. However if some cowboy puts a 13 amp plug onto a bit of 2.5mm cable runs it round the skirting to a few sockets that is considered temporary and is not covered by part P. Don't ask me I'm just a mechanical engineer.

I'm not suggesting that this is "good practise" solution just that it was legal - last year.

+1

Keith

 

[Rhossydd]

4: Ensure all legal and insurance aspects are covered.

That could be the most important issue of all.
If an installation looks 'dodgy' to a surveyor it could effect the saleability of your house and end up costing more than you save. The other, hopefully very unlikely, nightmare is that in the event of a fire a loss adjuster won't like any illegal installations and make deductions, or worse, fail to make any settlement.

 

[Hemsby]

Perhaps we could get a qualified persons take on the difference in reality is between

1/ An “Electrically legally installed” spur socket in your garage/workshop with a 13amp fused 4 way trailing extension socket attached, which you then use for your equipment.


2/ Changing that same “Electrically legally installed” spur socket to a 13amp fused spur box, then running a radial from that containing 4/5 further sockets which you then use the same equipment.

Both examples have the opportunity to have the same overload situation.

Example 1/ would blow the fuse in the extension lead or possibly trip or fuse at the consumer box.
Example 2/ would blow the fuse in the spur box or possible trip or fuse at the consumer box.

I think everybody appreciates that a dedicated supply to the garage/workshop is necessary if you have heavy duty machinery or will run multiple machines at the same time.

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[AndyNC]

Hi, glynster

diynot.co.uk is a good forum for this. There are many discussion like this.

One option if you feel you can do the work yourself is to contact the local council and say your going to do the work.

If you don't replace the consumer unit, in west berks it's £200 for the council to approve the work, that includes an electrician to test the work. They will inspect the installation prior to testing.

In principle, you do the work, they check it and you get a certificate afterwards.

I did this last year, wired a kitchen and garage and re-arranged sockets. £200 + my time and cable etc.

Hope this helps
Andy

 

[riclepp]

With my garage I converted into a workshop, originally came off a single wire from the house (no idea as to size as it was there when we moved in), into a garage distibution box which fed 1 double light and a single double socket.

After discussion with a sparky, i bought all the stuff he recommended which was an 8 way fuze boxk and a range of RCB's two type of cable (one for lights and one for sockets),. I installed all the lights and scokets where I wanted them, fed all the wires in. He came and connected it all up and tested and issued a part p cert. His advice was sound as was from the information I told him and what the power needs of the tools were.

All in all I paid in the region of £800 for kit and testing and inspection and connection., so it is easy to do, just need the qualified sparky for the connection and tesing for the part p part