OK, so all the local electricians seem to be unavailable at the moment due to the COVID-19 thing.
While I wait, I thought I would see if I could work it out myself, just for something to do while I am waiting and to learn something new. Also, I will know how the job should be done properly when I get somebody to do it.
The sockets and junction boxes are now metal ones. There is also no fuse for the lamp which I think it would need.
So, if anyone is interested in teaching me, would this work?
Most here would advise you to get a professional in as learning the hard way can be very hard...
You really ought to have a separate fuse or MCB for the supply to the lights and the lantern.
Also I presume that lantern is a PIR sort so you did not plan to switch it? I would advise a local switch so you can independently turn it off/on for testing or replacing the lamp.
You could use a pair of FCU (switched fused spur, etc) to feed them to achieve that, but please not a 13A fuse! 3A should be fine.
Also don't go wiring it in to your consumer unit, if you really must try something out then put a 13A plug on a length of flexible cable and join that to the SWA at the sending end. Leave that part to when things are closer to normal and you can get someone in.
Most here would advise you to get a professional in as learning the hard way can be very hard...
You really ought to have a separate fuse or MCB for the supply to the lights and the lantern.
Also I presume that lantern is a PIR sort so you did not plan to switch it? I would advise a local switch so you can independently turn it off/on for testing or replacing the lamp.
You could use a pair of FCU (switched fused spur, etc) to feed them to achieve that, but please not a 13A fuse! 3A should be fine.
Also don't go wiring it in to your consumer unit, if you really must try something out then put a 13A plug on a length of flexible cable and join that to the SWA at the sending end. Leave that part to when things are closer to normal and you can get someone in.
OK, that's all good to know - I'm not planning to actually do anything practical, just draw up a diagram of how it should all go together so that I can understand things. There is only so much housework you can do a day without it getting tedious.
Even if I can do this in the evenings then its something to sort of look forward to!
Thanks again for helping and I will get another diagram drawn up after I have had a careful read through of your instructions to make sure that I understand things in a practical sense.
OK, so it would use two FCUs, one for the lantern and the other for the light and the latter would replace the pull switch? Or, I suppose one switched FCU for the lantern and one unswitched FCU for the light with the pull cord, but seems easier to me to just replace the pull cord with the switched FCU?
OK, so it would use two FCUs, one for the lantern and the other for the light and the latter would replace the pull switch? Or, I suppose one switched FCU for the lantern and one unswitched FCU for the light with the pull cord, but seems easier to me to just replace the pull cord with the switched FCU?
If you need to operate the light with any risk of wet hands then you should retain the pull-chord switch. Then use either an unswitched FCU or (probably easier) have a 2nd switched one that you don't rely on for the functional switching. They can be placed somewhere out of common reach so they are used only for maintenance.
If you need to operate the light with any risk of wet hands then you should retain the pull-chord switch. Then use either an unswitched FCU or (probably easier) have a 2nd switched one that you don't rely on for the functional switching. They can be placed somewhere out of common reach so they are used only for maintenance.
Excellent ideas there, thanks. I doubt very much that anybody will be using the switch with wet hands, but at the end of the day this is an outside shed, so it could happen. Better safe than sorry, I say - so I will be keeping the pull switch as you suggest and using the FCUs for fusing down and maintenance.
New wiring diagram to come!
Thanks again, very much appreciated. If you ever have any IT questions or need mechanical engineering advice then I might be able to help you too!
I understand that you are aware that any or attempt to do the work your self, but by doing any work are have you insurance for any work that is carried out on your property and your self, just to added by doing any work you will be putting your self or your family at risk.
I understand that you are aware that any or attempt to do the work your self, but by doing any work are have you insurance for any work that is carried out on your property and your self, just to added by doing any work you will be putting your self or your family at risk.
Thanks for the message. For clarity, I am not going to put anyone at risk with this, its purely for educational purposes. The thread makes that quite clear but I do appreciate that its a lot to trawl through.
Yes, of course - so the supply and load earths in the FCUs should be linked together, yes? Bit of a schoolboy error there and I thought I was doing quite well!
Yes, of course - so the supply and load earths in the FCUs should be linked together, yes? Bit of a schoolboy error there and I thought I was doing quite well!
They will be as long as you use the correct terminals! Your diagram did not show that, though normally it would simply be assumed that whoever wired it up would have sufficient knowledge to do it right, and there is no need to link them as they are on a common strip of metal.
Generally FCU (and similar) will have two sets of earth terminals as the incoming power is connected to 3 terminals 'permanently' from the main wiring (i.e. L, N & E), and the other 3 are for connection of the load. You should not have to disturb the 'fixed wiring' to make that change as it would invalidate the test certificate, etc, if it were modified by removing and reconnecting part of it.
Originally 13A sockets would generally only have one set of terminals (i.e. 1 each L, N and E) as even when wired as an intermediate part of a ring (or multiple-outlet spur) there was no need for a 2nd as each terminal could take two wires.
More recently though you will find 13A sockets typically have 2 earth but still only 1 each L & N. This is for "high integrity earthing" on a ring, etc, where the pair of earth wires (going in and out) are separately terminated. The idea behind this is not to have a single point of failure for the earth in the event of a loose screw, etc, and it is really aimed at offices, server rooms, etc, with a large amount of leaky electronic equipment where an open earth has an immediate risk due to the sum of all currents being significant even outside of a fault situation.
More essential technical advice from the team at ELECSA. As part of their normal operation many electronic items, such as computers, printers, games consoles and the like, can cause a current to flow i
They will be as long as you use the correct terminals! Your diagram did not show that, though normally it would simply be assumed that whoever wired it up would have sufficient knowledge to do it right, and there is no need to link them as they are on a common strip of metal.
Ah, yes, I was thinking that after posting but I have no experience with FCUs and its difficult to tell by looking at images on the web. With a bit of time after posting, I realised that they would be joined together.
So, all the diagram needs to make it right is to have one of the earth terminals connect the to the back box then?
Generally FCU (and similar) will have two sets of earth terminals as the incoming power is connected to 3 terminals 'permanently' from the main wiring (i.e. L, N & E), and the other 3 are for connection of the load. You should not have to disturb the 'fixed wiring' to make that change as it would invalidate the test certificate, etc, if it were modified by removing and reconnecting part of it.
Originally 13A sockets would generally only have one set of terminals (i.e. 1 each L, N and E) as even when wired as an intermediate part of a ring (or multiple-outlet spur) there was no need for a 2nd as each terminal could take two wires.
More recently though you will find 13A sockets typically have 2 earth but still only 1 each L & N. This is for "high integrity earthing" on a ring, etc, where the pair of earth wires (going in and out) are separately terminated. The idea behind this is not to have a single point of failure for the earth in the event of a loose screw, etc, and it is really aimed at offices, server rooms, etc, with a large amount of leaky electronic equipment where an open earth has an immediate risk due to the sum of all currents being significant even outside of a fault situation.
More essential technical advice from the team at ELECSA. As part of their normal operation many electronic items, such as computers, printers, games consoles and the like, can cause a current to flow i
The main oddity of the diagram is in some cases you identify terminals (e.g. L1, L2) but in other not. Though I guess you are using the colour to indicate function (with yellow for earth)?
If you have metal accessories such as back boxes then you ought to have them connected to the earth. Although plastic boxes often have an earth screw as a junction point if needed, the box does not require earthing as they are insulated.
Some installations only conenct earth to the fitting (socket, switch, etc) and rely on the fixing screws to earth any metal back box but that is generally not considered good practice.
The main oddity of the diagram is in some cases you identify terminals (e.g. L1, L2) but in other not. Though I guess you are using the colour to indicate function (with yellow for earth)?
If you have metal accessories such as back boxes then you ought to have them connected to the earth. Although plastic boxes often have an earth screw as a junction point if needed, the box does not require earthing as they are insulated.
Some installations only conenct earth to the fitting (socket, switch, etc) and rely on the fixing screws to earth any metal back box but that is generally not considered good practice.
Yes, I have generally used the terminals that are available on the parts, but I have not always indicated earth points on back boxes, I don't think. Let me redraw later for you.
Okay, so here is hopefully the last instalment and I think that with all of your help, I finally understand things now.
I have the detail now for the FCUs, they are 5 terminal, 2 X L & 2 X N for supply and load, then one for E.
The earth terminals on the boxes are now made clear, in green, and I have added a key for clarity. You will also see that the boxes/enclosures are now colour coded too to show metal (black) and plastic (red). I have earthed the plastic pull switch box, too. I know it doesn't need it but I thought I'd do it anyway.
There are many ways to do any one job but given the stuff you already have and the scale of it that is probably the most cost effective. If doing more circuits, or starting from scratch, it might have been worth looking at an unpopulated "garage consumer unit" to put in some MCB (instead of the FCU) for switching and current limiting, as well as being a point for terminating the SWA cable and an area for joining cables, but the FCU have the advantage of isolating both L & N which is better if you are working on something.
There are many ways to do any one job but given the stuff you already have and the scale of it that is probably the most cost effective. If doing more circuits, or starting from scratch, it might have been worth looking at an unpopulated "garage consumer unit" to put in some MCB (instead of the FCU) for switching and current limiting, as well as being a point for terminating the SWA cable and an area for joining cables, but the FCU have the advantage of isolating both L & N which is better if you are working on something.
Ah, thanks so much. I really can't express how helpful you have been.
All I need to do now is wait until I can get a professional in to do the job but you have given me a thorough understanding of what is needed with the parts I have.
Its been good to learn something new. I had an idea but there were grey areas and this exchange has made me do a bit of reading up and a bit more listening to you to fill those grey areas in.
The old lockdown isn't easy as I have my 16 year old autistic son with me all day and there is no respite without going to work. He is at the severe end of things, hasn't spoken all of his life and doesn't use any communication aids. We recently had him medicated as he had become quite agressive and my wife was getting frightened of him (and so was I at times).
A bit of a chat with you has made things easier, given me something to think about in the daytime and solve in the evenings.
So, thanks a lot. If I can ever help you with the things I mentioned earlier then let me know and it will be a pleasure to return the favour.
No problem with the help! Hopefully things will improve soon and you can get the job done and a bit more freedome to manage your son.
Most electrical wiring systems are fairly simple in terms of underlying theory, but the Devil is in the Detail to do with safe and reliable operations which is why the wiring regulations are 500+ pages and not just a couple of basic points!
The 'wiring regs' BS7671 are not very readable as well as being a significant price (£95 for current 18th edition), but the IET also do a set of guidance notes to expand on the regs and to include other aspects from other standards such as building and fire regulations, access for the disabled, etc. If you do want a book to get a good overview of how electrical work should be approached in the UK and some of the not-so-obvious points, then the IET "Guidance Note 1: Selection & Erection" is as good a place to start as any.
I see it for sale on Amazon, etc, but I would generally go direct to the IET web store to be sure it was the real one! The IET ship by FedEx (or did last time I used them a month or so ago) so delivery is pretty fast and reliable for your money.
No problem with the help! Hopefully things will improve soon and you can get the job done and a bit more freedome to manage your son.
Most electrical wiring systems are fairly simple in terms of underlying theory, but the Devil is in the Detail to do with safe and reliable operations which is why the wiring regulations are 500+ pages and not just a couple of basic points!
The 'wiring regs' BS7671 are not very readable as well as being a significant price (£95 for current 18th edition), but the IET also do a set of guidance notes to expand on the regs and to include other aspects from other standards such as building and fire regulations, access for the disabled, etc. If you do want a book to get a good overview of how electrical work should be approached in the UK and some of the not-so-obvious points, then the IET "Guidance Note 1: Selection & Erection" is as good a place to start as any.
I see it for sale on Amazon, etc, but I would generally go direct to the IET web store to be sure it was the real one! The IET ship by FedEx (or did last time I used them a month or so ago) so delivery is pretty fast and reliable for your money.
OK, thanks a lot and maybe I'll get a copy of the book for some further reading. Pic of the trench attached and I have run the SWA out of the bottom of the summer house and clipped in in place inside, leaving a metre or so spare where it will be joined up to the consumer unit. I'll leave the hutch end so that whoever does the job can decide where they want it to go in.
OK, so I have one more question! Would it be possible to tee out of the armour with some more armour to run to some lights? I have some tall trees in the garden and it would be nice to uplight them but I don't really trust the solar lights that you can buy, plus then you need to put the solar panel somewhere that will get enough daylight.
I suppose I am imagining some kind of underground junction box, does that exist for this purpose, do you know? If so, what would you run it to, IP rated sockets on the bottom tree trunks or what?
Also, I assume there is load to consider - would I need to work out the load before I start adding stuff willy nilly? I would guess so.
Generally speaking lights take relatively little power so you should not have much of a loading issue in any case.
While you do get underground cable joint that is way too much cost & trouble for this, much simpler would be to take any other cable runs in to one of the places where the current cable terminates and join it there (or feed from a FCU) if you really need 240V.
But unless you really want serious levels of lighting I suspect you might be better to look at some low voltage lights (i.e. that run from a safe 12V supply or similar) where you have far less safety issues to consider and could get away with less cable protection, digging depth, etc, for feeding them as a result.
Generally speaking lights take relatively little power so you should not have much of a loading issue in any case.
While you do get underground cable joint that is way too much cost & trouble for this, much simpler would be to take any other cable runs in to one of the places where the current cable terminates and join it there (or feed from a FCU) if you really need 240V.
But unless you really want serious levels of lighting I suspect you might be better to look at some low voltage lights (i.e. that run from a safe 12V supply or similar) where you have far less safety issues to consider and could get away with less cable protection, digging depth, etc, for feeding them as a result.
How about if I take a feed from my existing sockets in the summer house and run it to an outside socket on the rear of the summer house, then plug the transformer for the lights in there? That's if you can get an outside socket that will be big enough to take a bulky transformer plug?
If you are looking at a bulky transformer-plug then I would say you ought to put it indoors, or have a small box added outside to shield the whole lot from the weather. Outdoor 13A sockets are generally fitted with covers that are designed to close on a normal sized plug to provide shielding from rain, etc, and you won't get that with a wall-wart supply inserted.
Depending on your garden layout it makes sense to put a suitable 13A socket & protection in a convenient place (either summer house or shed) and then run the 12V cable(s) out to the lights.
As Midwest suggests you can put in ducting for running cables underground. For SWA you don't need to - but it allows you to add/replace the cable later if you do (and it is not too windy/tight to pull through).
If you want to run normal wire underground, of the sort that 12V lights typically have, then it would be a big advantage in terms of protecting it from damage in the soil and allowing cables to be replaced later if needed. If you are using 12V (safe from shock) and it is not a critical function (decorated garden lights) then you can get away with less burial depth if you decide the risk of a gardening accident is acceptable compared to the time/effort of trenching in the first place.
Some ducting comes with a pull-string already routed through it, otherwise you might have to use a "fish tape" to pull through a small rope and then pull any heavier cable(s) with it. No, I have no idea why they are called fish tapes!
That is surprising! The stuff I have looked at (Doncaster Cables BS5467) seems OK for direct burial, etc. But if there is ever the need to replace or add to it, then ducting is an excellent investment!
In our case (project currently in limbo with lock-down) we were thinking of running some network cable in along side the main power SWA in overall 125mm duct, not that we need it now, but just in case we ever need it in the future. Some network cable has black harder UV-tolerant sheath so should be OK for the damp environment in the duct but would not survive being buried in stony ground.
Sorry for the late reply, thanks, yes - that's what I thought, is there an alternative to bulky transformer plugs with 12V systems and would it be possible for me to alter the length of the cable if its too short for what I need?
Then again, I quite like the look of these Single External Spike GU10 Spot Black IP65 spots, but they are 240V, so how would I go about running wiring for these? I was under the impression that underground outside wiring should be armoured, but maybe something less substantial is okay for use with ducting? Or could the cable just be run over ground, so that its easy to see when out with the spade? So much to learn and so many questions! Its no wonder that you can't become an electrician overnight!
Thanks to both of you for your help.
Nick.
EDIT: P.S. The ground I am laying this stuff in is usually dry, it's tree covered and doesn't see much rain.
Leaving wires exposed on the ground is a bad idea, not only is there a risk of damage when gardening, it is also a trip hazard and gives even more access to rodents, etc, which might chew the cable.
For direct burial you really ought to use SWA cable as it is the best protected, even then for very rocky ground you should sand-fill the trench around the cable to stop stones causing high local pressure and possible damage.
If you put in a duct you can put any cable in it really, but the duct ends should be sealed to keep vermin out, etc, and also when the cable does exit the duct it has to be suitable for the environment there.
A common cable that is OK for outside use is the 'HO7RN-F' tough rubber cable such as:
H07RN-F Cable is a non armoured flexible mains and control cable designed primarily as a trailing cable for use in the supply of energy for portable or mobile equipment.The cable is Ideal for use with transformer pumps, welders grinders, temporary lighting cable and feed cables to heavy mobile...
www.superlecdirect.com
That is a bit chunky for lights, overall diameter is around 12mm, but it is pretty tough stuff. Also it would fit some of the sealed junction boxes that are advertised below the light you linked to, for example:
You can power the lights simple from a 13A plug with a 3A fuse, or hard-wired in to a FCU. If you do put it on a dedicated switch then, while it is not essential, I would typically put it on a double-pole switch just so if it gets badly damaged you can isolate both L & N with the switch (as you would get from a socket or FCU).
Unless it is from an RCD that you don't need for other things. Basically if you only switch the L then you make it safe by switching off, but an N-E short can still trip the RCD and the single pole switch wont stop that.
Edit to add: Use LED bulbs - lower power and longer life so less risk of damaging the water seal when changing them!
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Example of cable duct:
Underground Electric Power Cable Ducting Coil 32/40mm x 50m Black from Naylor. (0707RC4050B). Order Helpline ☎ 01752 692 221
www.drainagesuperstore.co.uk
[automerge]1587288441[/automerge]
Other might have more opinion on the matter, but it seems this cable would be OK for direct burial (i.e. without expense of additional duct) if there is low risk of damage:
Please note: If you require advice on which cable to use, how and where to install it, it is recommended that you will need to contact the relevant qualified tradesperson for the job as the Superlec Direct Team are not qualified electricians.
www.superlecdirect.com
It is not intended to flex as I think it is single strand wires (like 1.5mm T&E), really it is more of a fixed power feed, but in your case that should be fine. It is not armoured, so no issues of needing special glands to earth the armour and so the 3-core version would be fine with those IP68 junction boxes.
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