Shed wiring, 4 core armoured cable

weesunny · Post by **weesunny** » Sat Jun 10, 2023 10:05 am

Hi, I'm a newbie on here looking for some electrical assistance, hi to everyone!

I have an armoured cable that comes up through my patio about 2 meters away from the boundary wall, it used to come up into a shed that the old owners had. When I moved in years ago I put a shed up in a slightly different location and connected the 3 cores of the cable into a waterproof junction box and ran a 2.5mm cable with corrugated conduit into the shed a short distance to get sockets and light going. All has been working well for years.

Now I'm getting around to it I want to bury the armoured cable underground and bring it to the boundary wall by jointing it to extend it, add an outdoor double socket and then bring a further length of armoured cable into the shed. I have SWA glands and earthing nuts all ready to go.

Now all the problems! I checked the sockets in the shed with a socket tester and I have a live neutral reserve which was the first issue. I then was checking the armoured cable and found another core hidden down the sheath. Only 3 of the cores were being used in the wiring, I hadn't altered the cable so it must have been used like this by the previous owner. I tested the 4 cores with a non-contact voltage detector 2 of the cores are live, 1 neutral and 1 is the earth. I've no idea what to do now!

I was hoping this was just going to be a straightforward wire-up all the way through but I have no idea how to deal with this 4 core cable, any help much appreciated.

ericmark · Post by **ericmark** » Sat Jun 10, 2023 10:42 am

Testing is not as easy as it seems, I use a non contact voltage tester

: Testing for live.jpg (82.7 KiB) Viewed 1136 times

and it does have 4 bars so you get an idea when there are multi cores which one is line, but it is measuring using either the leads as aerials or you body as a capacitive link to get a zero reference.

So when you get unexpected readings, then it's time to unpack the leads and measure to some known earth, line or neutral, I know in theroy you can stick a rod in the ground, but that will only work if all is correct in the house.

Step one is test the house is OK, it is not impossible for line and the PEN to be swapped as it comes into the house, and with a home with wooden or plastic doors/windows/etc it could be like that for years without anyone realising. Bit like the birds landing on the power lines, it is unlikely, but you still need to start at the beginning and work out where the error is.

In theroy the SWA should be earthed, but with garden electrics it may only be earthed at one end, this instruction set from the IET is a bit dated, but it does go through most of the options, and this one talks about a broken PEN electrics is not quite as easy as it first looks.

There is a case for having a TT supply for sheds, specially when they are metal. Because a caravan and narrow boat are normally made of metal, TN-C-S supplies are banned for use with them, and this is also the case with mobile homes (although it was a little vague until latest wiring regulations) and any tin shed is clearly the same.

The TN-C-S supply has also caused problems with EV charging, with special loss of PEN detection being required, in the main garden tools are class II, so there is no earth, but patio heaters and lights have again raised the question of the safety of earthed class I equipment in the garden with a TN-C-S also often called PME supply.

Lucky loss of PEN is rare, so we don't see that many problems, I think I have only once in UK come across it, although many times in Algeria.

So start where the SWA is connected in the house, make sure that's OK first. And use the leads where you can.

weesunny · Post by **weesunny** » Sat Jun 10, 2023 10:52 am

Thanks @ericmark. I have tried having a look at where the SWA enters the house but it is tricky. It runs up the side of the house and into the corner of the roof space, it is covered by insulation and it is a really tight space to access. I'll need to get up there and do a bit more investigation.

Someone-Else · Post by **Someone-Else** » Sat Jun 10, 2023 11:05 am

You can't just add a socket because the cable is there, the cable needs to be protected by a protective device, (It probably is, but the question is what is its rating and what is the rating of the cable) The idea is the protective device is there to protect the cable not what is at the other end. If there is a problem the cable could overheat, and set fire to its surroundings (in the loft)
Also, corrugated conduit offers hardly any mechanical protection at all. Have you ever made off a SWA gland before? I am sorry to say, but in this case you would be better off getting an electrician to do the job for you. Just because "it works" does not mean it is safe. Also an electrician will have a proper means of testing, what have you got?

weesunny · Post by **weesunny** » Sat Jun 10, 2023 11:40 am

Hi @Someone-Else, I am aware of all you have said already, the glands are no problem and I can test.

Neelix · Post by **Neelix** » Sat Jun 10, 2023 12:35 pm

If you are stumped I would recommend that you find a local spark

Water you can see
Gas you can smell
By the time you feel the electricity it may kill you

weesunny · Post by **weesunny** » Sat Jun 10, 2023 1:07 pm

Hi guys, just to be clear, I don't do things that put my life in danger and I am fully aware of electricians. I am stumped at the minute hence posting on the forum to see if anyone had any ideas. If I can't progress or am not comfortable with safety then the next stage will be to get an electrician. I'm just searching for some ideas to try some next steps before moving to call a spark.

Someone-Else · Post by **Someone-Else** » Sat Jun 10, 2023 1:19 pm

weesunny wrote: ↑Sat Jun 10, 2023 11:40 amHi @Someone-Else, I am aware of all you have said already, the glands are no problem and I can test.

What with? (I genuinely have no idea what you do or do not have, hence the question)

weesunny wrote: ↑Sat Jun 10, 2023 1:07 pmI don't do things that put my life in danger

According to who? You have already said that you have corrugated conduit running low down outside.

Don't take this the wrong way, its just that we don't want you to feel safe when the truth is you are not safe, and neither is anyone who lives or visits your property.

weesunny · Post by **weesunny** » Sat Jun 10, 2023 5:22 pm

Someone-Else wrote: ↑Sat Jun 10, 2023 1:19 pm
weesunny wrote: ↑Sat Jun 10, 2023 11:40 amHi @Someone-Else, I am aware of all you have said already, the glands are no problem and I can test.
What with? (I genuinely have no idea what you do or do not have, hence the question)

weesunny wrote: ↑Sat Jun 10, 2023 1:07 pmI don't do things that put my life in danger
According to who? You have already said that you have corrugated conduit running low down outside.

Don't take this the wrong way, its just that we don't want you to feel safe when the truth is you are not safe, and neither is anyone who lives or visits your property.

@Someone_Else I'm not sure why you're so aggressive and unhelpful but I had a look at other threads and I see you are a spammer, I presume this is to get your post count up as you don't add anything positive to posts you just throw in negative spam. If you have nothing useful to say then don't say it and go spam somewhere else!

Someone-Else · Post by **Someone-Else** » Sat Jun 10, 2023 6:25 pm

You are entitled to your opinion, as am I, I am only trying to protect you from yourself. Electricity does not care, it will kill anyone. It is you that is being aggressive. I also see you do not understand the definition of spam.

I have asked how you propose to test anything and as you have nothing to test with, you start to throw your toys out of your pram. Shut the door on your way out.

weesunny · Post by **weesunny** » Sat Jun 10, 2023 6:48 pm

Someone-Else wrote: ↑Sat Jun 10, 2023 6:25 pm You are entitled to your opinion, as am I, I am only trying to protect you from yourself. Electricity does not care, it will kill anyone. It is you that is being aggressive. I also see you do not understand the definition of spam.

I have asked how you propose to test anything and as you have nothing to test with, you start to throw your toys out of your pram. Shut the door on your way out.

You're just a forum troll and now trying to bully me off the forum, what a guy you are! I see I'm not the only one who has noticed the way you behave! Get off your high horse and wind your neck in, troll alert!!!!!

moderator2 · Post by **moderator2** » Sat Jun 10, 2023 6:58 pm

weesunny, As a newbie I believe you misunderstand what S-E is trying to explain regards safety regarding electrics. Please refrain from insulting any of the contributors on this forum.

OnlyMe · Post by **OnlyMe** » Sat Jun 10, 2023 7:04 pm

Welcome to the Electrical forum of ultimatehandyman where you will no longer get any electrical advice other than "call an electrician" from the likes of Neelix, ericmark and Someone-else.

weesunny · Post by **weesunny** » Sat Jun 10, 2023 8:17 pm

moderator2 wrote: ↑Sat Jun 10, 2023 6:58 pm weesunny, As a newbie I believe you misunderstand what S-E is trying to explain regards safety regarding electrics. Please refrain from insulting any of the contributors on this forum.

I don’t misunderstand.

I didn’t ask for advice on safety, I asked for advice on a matter, and the guy didn’t help at all. He has given no useful advice at all in relation to my post, has asked me for CV to justify myself to him, has given me a lecture telling me no one is safe at my property and has told “me to shut the door on the way out”. I have been treated in an aggressive manner and the thread has been ruined. He has not attempted to help, only to get on his high horse and give an unwanted and unneeded lecture.

This is meant to be an electrical forum, everyone knows that we can get electricians out so why is the first response to any question that he answers on the form “get an electrician”? I have checked other postings and that is all he does. The point of an electric forum is that it is the step before we go to an electrician.

As you can see from other posts on my thread I am not the only person who thinks so.

I am sorry if the guy feels he has been insulted but these people always get upset when they are called out. There has been an attempt to intimidate and bully me and the thread has been spammed rendering it useless.

Neelix · Post by **Neelix** » Sat Jun 10, 2023 8:41 pm

So @ weesunny how can you test the electrics? With what exactly?