Advice on fixing this outside mess

[RDB85]

Basically I’ve attended a friend house who asked me to see why his power to his sheds had stopped working. Any help or advice on fixing this mess please

 

[nicebutdim]

In hindsight singles would probably be better but I’ve got 30m of NYY and the price of cable and also selling the NYY.

This whole scheme has alarm installer written all over it.

Don't conform to stereotype.

 

[RDB85]

This whole scheme has alarm installer written all over it.

Don't conform to stereotype.

I’m not trying to. But you really don’t like anyone that works in that field. Also the original install was done by a qualified spark. What’s wrong with NYY or do you have a better suggestion.

 

[Diddy]

Hmm as an electrician I tend to check the source of power 1st and then work from there. You also seem convinced that you need to run a new cable...but only in your last post do you state/imply that the armour cable has been cut "somewhere".
If something is outside your normal work/comfort zone sometimes it is better to just accept it and get a person in that knows this type of work well.
Not knowing how to do something isn't embarrassing or anything like that, But winging it and guessing is wrong on so many levels. You could get someone in and even learn from them for next time.....

 

[RDB85]

Hmm as an electrician I tend to check the source of power 1st and then work from there. You also seem convinced that you need to run a new cable...but only in your last post do you state/imply that the armour cable has been cut "somewhere".
If something is outside your normal work/comfort zone sometimes it is better to just accept it and get a person in that knows this type of work well.
Not knowing how to do something isn't embarrassing or anything like that, But winging it and guessing is wrong on so many levels. You could get someone in and even learn from them for next time.....

It’s a bit obvious that a new cable is needed as it’s anyone’s guess as to where it’s been cut. Maybe as the RCD was off I also decided to look in the enclosure. As you know it’s outside and all.

Having done that and then trying the consumer unit I then found the problem. I’m not trying to wing it or guess it. I’ve a Level 2 and 3 2365 so I’m okay with having some knowledge.

I could get someone in but most of the sparks I know feel confident that I could do that myself.

 

[nicebutdim]

I’m not trying to. But you really don’t like anyone that works in that field. Also the original install was done by a qualified spark. What’s wrong with NYY or do you have a better suggestion.

It was a tongue in cheek post, but not entirely inaccurate.

Your suggestion of replacing the cable cable prior to the apparent discovery that it has been cut. You reasoning behind using NYY was based on 'having all cable of the same construction' and later 'because you had some to sell'. I'd love to understand the reasoning behind all of this, but accept that I'll never know the facts.

As for what I'd do? Well I'd make decisions based on what exists and what needs to be achieved. The very things people have been trying to learn from you since yesterday, but apparently you're only bringing you make that assessment after already deciding on part of a planned way forward.

 

[nicebutdim]

It’s a bit obvious that a new cable is needed as it’s anyone’s guess as to where it’s been cut. Maybe as the RCD was off I also decided to look in the enclosure. As you know it’s outside and all.

The posts in this thread indicate you knew this was obvious a whole day before learning the cable has apparently been cut.

Incredible foresight on your part

 

[RDB85]

The posts in this thread indicate you knew this was obvious a whole day before learning the cable has apparently been cut.

Incredible foresight on your part

Isn’t it just.

 

[RDB85]

It was a tongue in cheek post, but not entirely inaccurate.

Your suggestion of replacing the cable cable prior to the apparent discovery that it has been cut. You reasoning behind using NYY was based on 'having all cable of the same construction' and later 'because you had some to sell'. I'd love to understand the reasoning behind all of this, but accept that I'll never know the facts.

As for what I'd do? Well I'd make decisions based on what exists and what needs to be achieved. The very things people have been trying to learn from you since yesterday, but apparently you're only bringing you make that assessment after already deciding on part of a planned way forward.

Okay so what currently exists is an RCD and an outside box. Two radials done in 4mm NYY. And a 1.5mm SWA that’s been cut. I’ve 30m of NYY which I’ve decided to use as selling it online is a right pain and with the price of cable going up it’s not worth buying new cable when the NYY seems appropriate cable to use.

I’ve also got some 25mm Galv Conduit and an assortment of Saddles and End and Through Boxes.

All I’m doing is asking for some advice and trying to help a friend restore power to his sheds.

 

[timhoward]

Okay so what currently exists is an RCD and an outside box. Two radials done in 4mm NYY. And a 1.5mm SWA that’s been cut. I’ve 30m of NYY which I’ve decided to use as selling it online is a right pain and with the price of cable going up it’s not worth buying new cable when the NYY seems appropriate cable to use.

I’ve also got some 25mm Galv Conduit and an assortment of Saddles and End and Through Boxes.

All I’m doing is asking for some advice and trying to help a friend restore power to his sheds.

I'm all for trying to draw a line as many on here would like to help you. My gentle suggestion is to just admit mistakes and move on. It's not like we don't all make mistakes too. I'm sure you've already learned things from this. e.g. assume nothing and work methodically when fault finding (find out what does work first)

So, you currently have a B40 device for the supply circuit. Is this RCD protected in the garage board or not?
Have you got a cable that's CCC exceeds 40 amps after appropriate deratings?
Until you have the supply circuit design sorted you can't move on to the details.

Brief research shows that 4mm NYY-J clipped direct is rated under 40 amps, so by the time it's in galv conduit I'd doubt this is going to cut it. So you may need to rethink the protective device and/or the cable.
Does that get you started?

 

[westward10]

What distance does this cable have to be pulled through the conduit?

 

[nicebutdim]

All I’m doing is asking for some advice and trying to help a friend restore power to his sheds.

Here's some I posted earlier, perhaps you didn't see it.

Galv conduit would certainly provide good mechanical protection. @timhoward raises the issue of CCC - I don't know the differences between SWA and NYY off the top of my head, nor the correction factor when enclosed in conduit, but you may need to increase cable size and also that of the conduit.

 

[RDB85]

I'm all for trying to draw a line as many on here would like to help you. My gentle suggestion is to just admit mistakes and move on. It's not like we don't all make mistakes too. I'm sure you've already learned things from this. e.g. assume nothing and work methodically when fault finding (find out what does work first)

So, you currently have a B40 device for the supply circuit. Is this RCD protected in the garage board or not?
Have you got a cable that's CCC exceeds 40 amps after appropriate deratings?
Until you have the supply circuit design sorted you can't move on to the details.

Brief research shows that 4mm NYY-J clipped direct is rated under 40 amps, so by the time it's in galv conduit I'd doubt this is going to cut it. So you may need to rethink the protective device and/or the cable.
Does that get you started?

I know we all make mistakes. I’ve learnt from it. Every day is a school day as the saying goes. If designing the circuit the CCC Table 4D2A

3 core in conduit is 27 amps in Conduit and 32 amps Clipped Direct.

 

[RDB85]

What distance does this cable have to be pulled through the conduit?

It’s about 10m 4m is a straight run horizontal. Then there is a bend around the corner. 4m straight run and then 2m vertical.

 

[RDB85]

What could I use to join the two boxes. If I have a Wiska box below and the RCD Enclosure above it.

 

[Diddy]

Im still somewhat intrigued as to how you have identified a break in the origional cable

Right so I’ve done some further investigation back at the consumer unit in the garage. Tested for Continuity and IR and got nothing. Open up the Consumer unit to find that when it was converted into a room. They decided to cut it. So the feed that goes from there to the RCD is no more.

The NYY-J is what was left over from the previous installation for both shed radials.

Cut it where ? Inside the consumer unit or elsewhere. Is it the case that the cable is inches short now or is there an as yet unidentified break in the original cable? Ir came back nothing ? Unsure what that means. Continuity came back nothing - I assume that means you didn't get a reading when you tested each core to say earth for continuity ?
But how could you test for continuity without opening up the consumer unit 1st ? You do know to do a continuity test you must somehow create a loop for the test to be conducted. Be that through a long lead or using traditionally the earth as your potential loop .....and so on.
I still think you should be mentored for this instance just so that you have the practical knowledge next time. But if my questions and what I have said sound harsh there IS a point to them - You could be turning a 30 min fix into a day long job....even if you are doing it for a friend and doing it free of charge so no ulterior motive....It's simply preferable to fix what is there (If no unidentified break in the cable elsewhere) as opposed to starting again ....I/We are trying to save you some time and possibly money and as already mentioned maybe even saving you from installing a cable in a manner that renders the install "incorrect" with regards to cable size and OC protective device selection....