Hi all Before I start, i'm planning on getting someone to take a look first but im asking so I know roughly what to expect and an idea of how much the parts would cost. I have a detatched garage and at the moment when I need power in there it means running an extension cable from the house so im looking at having something more permanent. I understand the proper way is to have cable fitted to the Consumer unit and to the garage but I also believe that it can be done from a fused spur. Ive done a search and I can see how part of it can be done but its the rest im unsure of. Adding a fused spur to an existing socket seems fairly straightforward and it looks like you need 2.5mm twin and earth cable. From the fused spur to the garage, it would be buried in the wall inside the house and then in conduit outside, buried outside under the ground and then into the garage. So, could you answer these? 1: from the socket to the fused spur, is the cable 2.5mm twin and earth? 2: from the fused spur to the garage, what cable is needed (ie 2.5mm, armoured, etc - it will probably be buried in steel conduit 3: does the cable need to go to a CU in the garage? Like ive said, ill be getting someone to do the work, im just wanting an idea of what to expect.
Loads of things to consider here Vulcan, Whats the load going to be in the garage ? Are there any extraneous conductive parts in the garage ? Is the existing house circuit RCD protected ? Whats the current earthing arrangement ? Thanks Matt
Matt This is stuff im not entirely sure on or what you mean in simple terms. I can say that I plan to have one strip light and a double socket, socket used for power tools etc, nothing that would be on continuous. by extraneous conductive parts you mean metal parts? Its all wood and breeze block, only metal being the garage door. Im not entirely sure what you mean by RCD protected or earthing arrangement. Theres a CU in the kitchen marked with the lighting/sockets circuits. sorry if I sound a bit dim, im more into the plumbing side
Simplest thing to do is get three electricians to give you an estimate. You decide what you want in the garage and let them decide how to do it. I really don't understand why people ask so many questions on a forum when they just need to get the answers from the sparky. I don't believe you tbh. I think your doing it yourself.
A RCD also has other names like a ELCB-c and it measures the power in and power out and if they don't match disconnects the supply as it is assumed it has gone instead to earth. They all have a "test" button but in a house there are two types. 100 mA is used with a TT supply (means you have an earth rod) and does not protect the person but a 30 mA now used for all sockets and buried cable (with one or two exceptions) protects the person. So you need a RCD on any new sockets, however you can get a RCD FCU so it is really no problem. With a house with multi-ring finals using a FCU is likely OK but one has to consider the extra load and as it is we have not idea what the load will be. Distance is also a consideration volt drop may mean fluorescent lights will not work and no distance is given. Twin and earth is for interior wiring and it is hard to thread through conduit. Outside I would use steel wire armoured cable (SWA) I know we see twin and earth outside but that does not make it right. In the main to simply replace an extension lead I would use a metal FCU RCD (13A fuse) so I can fit a gland and SWA to a double metal socket in garage and from that to a switched FCU with 3A fuse for the lights. That's assuming no RCD in consumer unit. I would not fit a consumer unit in the garage. However if the user wants to use loads of power tools so more than 13A is required then I would fit a consumer unit in the garage and the supply would have to come from house consumer unit. If possible I would wire before the house RCD and have the RCD in the garage. If you intend to use voltage dependent equipment in the garage like a freezer or fluorescent light then you need to work out the volt drop. You will notice most freezers say not to use with an extension lead that is because any volt drop will shorten their life. With inverter models should not be a problem but I note the warning is still in the instructions.
I know it was probably meant tongue in cheek but im fully aware of the consequences of faulty/incorrect electrics. If I did do the work myself, id be getting someone in to check it over anyway and approve it so its all above board, what with all the regulations and such.
There would be nothing permanently turned on like a freezer and I might have to look at different lighting. id estimate the distance would be about 10m from the house to the garage.
As MGW says you need SWA cable. There are good videos on You Tube on how to terminate this but it can be tricky to get it right.But there are so many other things to consider such as earthing arrangements & cable sizes, that need to be established. Legally this is not a DIY job and a little knowledge is a dangerous thing. If you knew how to do it correctly and you did it, it would be done! I really think you need to take Unphased's advice.
Steel Wire Armoured cable (SWA) is often the choice for transporting electricity under ground because it is very tough and resistant to aggressive environments. However, it needs to be terminated correctly and few DIYer's even bother to do that; they just shove the end through a hole in the accessory case and bodge it. The correct use of SWA glands is paramount to good practice and safety and you won't have the skill to do it. Spurring off a circuit in the house is very poor design. Technically it is safe but doesn't achieve the best result. A 2-way CU on the end of a SWA on its own sub-main is the correct solution.
These sorts of 'oblique' questions remind me of the one's where someone with a medical problem starts off, "My Mate has this problem.....................what shall I tell him/her to do?? Carry on eh OP, tiz your family not mine!
Hi Vulcan while your on i have a plumbing problem. Tank in attic, combi boiler and old DHW cylinder in cupboard. Can I bypass the tank...and what should i use...plastic overflow pipe or a combination of copper and plastic...altho I dont know how to solder and never used plastic pipe ? RS
Well this is a late response as another periodic trawl through the forum unearths someones ridiculous question, and i'm not being rude when i say that. I'm afraid you came across as a complete no hoper attempting to do the job yourself or you want a bona fide Electrician to do the job for nothing! No offence intended but you're the type of client that makes me want to run a mile!
Forums
Facebook
Twitter
You Tube
Instagram
Shop