Advice on fixing this outside mess

RDB85 · Oct 6, 2023

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

Mikegh · Oct 6, 2023

What's the mess? Not seeing it

westward10 · Oct 6, 2023

Is that the reason it has stopped working?

RDB85 · Oct 6, 2023

westward10 said:
Is that the reason it has stopped working?

Pretty much due to water ingress. Any recommendations on how to fix it and neaten it up.

timhoward · Oct 6, 2023

So is RCD tripping?
Obviously cracked box, SWA not earthed this end, and B32 possibly feeding two radials (or is it a RFC?)

All I'd care about is understanding the reason why it doesn't work, and then whether the incoming SWA is sound. IR test it, continuity test it. I'd assume the other end is a fuse or MCB?

Then I wouldn't want to do anything other than start again. From what you've shown I've two instant ideas:
You could fit a little IP65 CU, re-terminate the SWA into that (but earth it), and fit a couple of B16 RCBO's, one for each shed.

Or you could re-terminate the incoming SWA into a galv besa box, or resin joint, extend the SWA and and fit a little garage CU inside the shed.
He could have some lights then as well.

RDB85 · Oct 6, 2023

timhoward said:
So is RCD tripping?
Obviously cracked box, SWA not earthed this end, and B32 possibly feeding two radials (or is it a RFC?)

All I'd care about is understanding the reason why it doesn't work, and then whether the incoming SWA is sound. IR test it, continuity test it. I'd assume the other end is a fuse or MCB?

Then I wouldn't want to do anything other than start again. From what you've shown I've two instant ideas:
You could fit a little IP65 CU, re-terminate the SWA into that (but earth it), and fit a couple of B16 RCBO's, one for each shed.

Or you could re-terminate the incoming SWA into a galv besa box, or resin joint, extend the SWA and and fit a little garage CU inside the shed.
He could have some lights then as well.

Yes the RCD has tripped. It’s feeding two radials of 4mm 3 core NYY to each shed. Which has its own light, socket and FCU. The other end of the cable is a 40a MCB.

I’ve got a Wiska 1010 box and a Vent Plug, if the SWA is no good I may replace with NYY so it’s all the same cable. Would this need to be earthed with an Earth locking nut on that end?

Also replace the connector block with 222 Wago?

westward10 · Oct 6, 2023

You don't replace a cable so it matches the other you replace it with a suitable cable. NYY-J does not need an earth lock nut. I'm not sure you are experienced enough to be undertaking such things without supervision.

timhoward · Oct 6, 2023

RDB85 said:
Yes the RCD has tripped.

As bad as that lot looks, the reason could be downstream of there. You need to IR test the two radials in turn.

RDB85 said:
if the SWA is no good I may replace with NYY so it’s all the same cable. Would this need to be earthed with an Earth locking nut on that end?

Does the SWA have a cable route where it would otherwise need RCD protection at source? You may need to consider this before changing cable type.

Wagos? Yes!

RDB85 · Oct 6, 2023

westward10 said:
You don't replace a cable so it matches the other you replace it with a suitable cable. NYY-J does not need an earth lock nut. I'm not sure you are experienced enough to be undertaking such things without supervision.

What I’m saying is if the SWA is no good. I’m going to replace it with NYY-J Meaning it’s the same cable type used throughout the installation.

RDB85 · Oct 6, 2023

timhoward said:
As bad as that lot looks, the reason could be downstream of there. You need to IR test the two radials in turn.

Does the SWA have a cable route where it would otherwise need RCD protection at source? You may need to consider this before changing cable type.

Wagos? Yes!

The SWA runs into the Garage Consumer unit. It’s on its own MCB. What would be best used to connect the two boxes together. Something like a Brass Compression Gland.

oscar21 · Oct 6, 2023

timhoward said:
So is RCD tripping?
Obviously cracked box, SWA not earthed this end, and B32 possibly feeding two radials (or is it a RFC?)

All I'd care about is understanding the reason why it doesn't work, and then whether the incoming SWA is sound. IR test it, continuity test it. I'd assume the other end is a fuse or MCB?

Then I wouldn't want to do anything other than start again. From what you've shown I've two instant ideas:
You could fit a little IP65 CU, re-terminate the SWA into that (but earth it), and fit a couple of B16 RCBO's, one for each shed.

Or you could re-terminate the incoming SWA into a galv besa box, or resin joint, extend the SWA and and fit a little garage CU inside the shed.
He could have some lights then as well.

Slightly off topic but this has intrigued me for ages, you state "B32 possibly feeding two radials" as that's what it looks like but I don't believe that device has any over current protection at all, its just an RCD with contacts rated to 32A just like the 63A and 80A RCD's we so often see in consumer units.

The bit that intrigues me is why would manufacturers make an RCD that is only rated to 32A when they produce so many that are 63/80/100A rated. what could it possibly be used for that a vastly more common higher rated one couldn't be. All it does is confuse people into thinking its got some kind of over current protection, I'll bet there are hundreds of these devices installed for just that purpose.

nicebutdim · Oct 6, 2023

oscar21 said:
Slightly off topic but this has intrigued me for ages, you state "B32 possibly feeding two radials" as that's what it looks like but I don't believe that device has any over current protection at all, its just an RCD with contacts rated to 32A just like the 63A and 80A RCD's we so often see in consumer units.

The bit that intrigues me is why would manufacturers make an RCD that is only rated to 32A when they produce so many that are 63/80/100A rated. what could it possibly be used for that a vastly more common higher rated one couldn't be. All it does is confuse people into thinking its got some kind of over current protection, I'll bet there are hundreds of these devices installed for just that purpose.

I've seen quite a few showers which were later additions to installations and fed from a '63A' RCD. Presumably the installer laboured under the misapprehension that this rating represented overcurrent protection.

On your later point I've often wondered if it wouldn't be cheaper for manufacturers to produce only one current rating, rather than a range - 100A being the obvious suggestion. Small 'garage' boards often have an RCD mainswitch rated at 40A. 16A 3ph RCD protected interlocked sockets are often supplied (if indeed an RCD is supplied) with 25A devices. All of these are perfectly acceptable and fit for purpose, but their availabilty suggests there must be a commercial reason for offering a wide range - just not one that is obvious to me.

davesparks · Oct 6, 2023

RDB85 said:
I’ve got a Wiska 1010 box and a Vent Plug, if the SWA is no good I may replace with NYY so it’s all the same cable.

How is the SWA installed and how would your proposed new NYY be installed?

There's a lot more to selecting the right cable for the job than just making it all the same type.

RDB85 said:
Would this need to be earthed with an Earth locking nut on that end?

Is this a trick question? NYY doesn't have any armour to earth.

RDB85 · Oct 7, 2023

davesparks said:
How is the SWA installed and how would your proposed new NYY be installed?

There's a lot more to selecting the right cable for the job than just making it all the same type.

Is this a trick question? NYY doesn't have any armour to earth.

The SWA goes into the L N terminals on the RCD. It’s then fed into the Garage Consumer Unit on an MCB. Then the Garage has its own feed back to the Consumer unit in the house. It’s currently buried under paving in the garden.

The new NYY-J would be installed in Galvanised Conduit.

nicebutdim · Oct 7, 2023

RDB85 said:
The SWA goes into the L N terminals on the RCD. It’s then fed into the Garage Consumer Unit on an MCB. Then the Garage has its own feed back to the Consumer unit in the house. It’s currently buried under paving in the garden.

How would the proposed NYY-J replacement be routed back to that consumer unit?