Power from Summerhouse to shed

[nick00]

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?

Thanks, Nick.

 

[buzzlightyear]

you are nearly there ,but one thing missing is a good spark to sort it out .

 

[pc1966]

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.

 

[nick00]

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.

Cheers,
Nick.

 

[nick00]

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.

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?

Ta,
Nick.

 

[pc1966]

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.

 

[nick00]

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!

Ta,
Nick.

 

[buzzlightyear]

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.

 

[nick00]

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.

Hi there,

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.

All the best,
Nick.

 

[nick00]

OK, here I have added the FCUs.

 

[pc1966]

OK, here I have added the FCUs.

That is the basic idea, assuming the two earth's of the FCU are connected

 

[nick00]

That is the basic idea, assuming the two earth's of the FCU are connected

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!

 

[pc1966]

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.

High Protective Conductor Currents

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

professional-electrician.com

 

[nick00]

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.

High Protective Conductor Currents

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

professional-electrician.com

OK, I will need to have a good read through the rest of this. Interesting stuff though and thanks for taking the time to explain things to me.

 

[pc1966]

So, all the diagram needs to make it right is to have one of the earth terminals connect the to the back box then?

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.

 

[nick00]

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.

Thanks again,
Nick.

 

[nick00]

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.

Thanks again for all of your patience!

Nick.

 

[pc1966]

That should be fine!

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.

 

[nick00]

That should be fine!

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.

All the best,
Nick.

 

[pc1966]

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.

All the best!