Electrical Disaster Recovery

[BigJock2005]

Hello All,

After a power cut in my garage conversion (done some 10+ years ago by the owners-before-previous) and an examination into the electrics, I discovered a right disaster, posted elsewhere for others' general amusement:

//www.diynot.com/diy/threads/disaster-to-cheer-up-your-sunday-but-not-for-me.458126/

What we have here is basically this:

A garage conversion was done, basic construction seems okay, and some of the garage length was walled-off to provide a utility room. At the end of the garage is a little study, so the conversion basically consists of a study, a utility room, and then a garage.

I've traced all the wiring since the power cut, and I've learned (to my horror) that all the sockets in the conversion are fed from a single socket which is a spur off the ground floor ring main. Into that socket is connected a 5-gang adapter, into which there are a number of plugs. Those plugs feed four double sockets in the utility room, and a further two in the study. A plug also powers the lights in the study.

The appliances in the utility room are a fridge, a washing machine, a tumble drier, and a charger for the hand-held hoover. In the study it's just a computer, monitor and printer. They are connected to one socket via a surge-protected computer supply.

Needless to say I have disconnected everything for safety. Temporarily I have run a 2-gang extension cable from the socket in the garage, into which the fridge (3A fuse) is plugged. In the other socket, I've told the missus she can run either the washing machine or the tumble drier. When she's not using either, I can plug in me computer.

Now I have to get this sorted, and I'm going to have to engage a pro, as this is beyond me time-wise and would need to get it certified anyway. Please let me have any comments on the following:

1. Temporary fix (me):
To get rid of the extension lead I though I could fit a double-pole 13A fused switch with an RCD such as the one below onto the incoming spur:

http://www.screwfix.com/p/safetysure-13a-rcd-fused-spur-white/26963

I will then connect two of the double sockets in the utility room to that (I can access all the cables) plus one of the sockets in the study (I only need 1 socket). If the total load exceeds 13A then it will of course trip. Any issue with that? Or having an RCD on the spur when there's one in the main CU as well?

2. Permanent fix (electrician):
There is a spare bay on the CU which I could use to take a spur from and run into the conversion. Could I then get an electrician to fit a CU on the end of that spur, and then properly connect a new ring main and light circuit for the conversion to that?

Any comments very welcome, I hope you enjoyed reading this saga, and it didn't bore you to death...

Best Wishes
Jock

 

[diyer56]

I've traced all the wiring since the power cut, and I've learned (to my horror) that all the sockets in the conversion are fed from a single socket which is a spur off the ground floor ring main. Into that socket is connected a 5-gang adapter, into which there are a number of plugs. Those plugs feed four double sockets in the utility room, and a further two in the study. A plug also powers the lights in the study.

....

1. Temporary fix (me):
To get rid of the extension lead I though I could fit a double-pole 13A fused switch with an RCD such as the one below onto the incoming spur:

http://www.screwfix.com/p/safetysure-13a-rcd-fused-spur-white/26963

I will then connect two of the double sockets in the utility room to that (I can access all the cables) plus one of the sockets in the study (I only need 1 socket). If the total load exceeds 13A then it will of course trip. Any issue with that? Or having an RCD on the spur when there's one in the main CU as well?

If one of the current plugs that is plugged into the 5 gang adapter feeds the required socket in the utility room you could just connect this plug to the single socket - removing the 5 gang adapter and the additional load. There is no point installing an RCD if there is another RCD in the CU.

With either your or my temporary solutions you wouldn't have any lights in the extension then either.

2. Permanent fix (electrician):
There is a spare bay on the CU which I could use to take a spur from and run into the conversion. Could I then get an electrician to fit a CU on the end of that spur, and then properly connect a new ring main and light circuit for the conversion to that?

Read more: //www.diynot.com/diy/threads/electrical-disaster-recovery.458241/#ixzz46sJcVeC8

Your electrician will be able to suggest a permanent fix. I wouldn't have thought the solution would be a CU though, perhaps a radial/ring for sockets from the spare way in the CU and then connect into the existing downstairs lighting circuit for the lights?

 

[ericmark]

My son stripped his house electrics and lived for a year with two 13A sockets supplying everything in the house while ceiling were removed and new cable fitted. Yes every so often he would forget what was running a blow a fuse. But blowing a fuse is not causing danger. Where we have danger is selecting extension leads which are under size or coiled up.

What you need to ensure id the freezer or fridge do not get too warm when a fuse ruptures. I know with my fridge/freezer and freezer after a power cut they display the warmest temperature reached until door is opened and then they show actual temperature.

What you need to do is separate inconvenience from danger, I have not really seen something which is dangerous in your pictures. Clearly what was done was wrong and leaves you with likely hood of a power failure, but since it was fused there was no danger.

 

[BigJock2005]

LOL! So I guess you're saying just replace the fuse and connect up again! I can see what your saying but with an unfused double socket feeding all that stuff it could pulling a constant 25A on the spur without blowing anything, which isn't great!
There's also some really bad terminations and exposed ends, they need to go.
Temporarily I think I will put in a 13A fused switch, tidy up all the excess cabling and reconnect some of the sockets, removing the rest. I can get to the lighting circuit so can connect the lights okay.
should be able to do that in a day quite easy.

 

[ban-all-sheds]

with an unfused double socket feeding all that stuff it could pulling a constant 25A on the spur without blowing anything, which isn't great!

Only if you overload the socket.

Overloading is to be avoided by design, not by using a protective device to limit it.

 

[securespark]

A 13A fused spur feeding a run of sockets?

 

[BigJock2005]

That's the temporary plan.
A 13A DP fused switch, which will fee 3 double sockets.
Not great, but I know the limitations until I can get a leccy man to sort a proper ring main.
I mean, I'm going to need a proper double socket in the garage for my man-tools.

 

[diyer56]

LOL! So I guess you're saying just replace the fuse and connect up again! I can see what your saying but with an unfused double socket feeding all that stuff it could pulling a constant 25A on the spur without blowing anything, which isn't great!

So just use one of the two sockets (at the original spur) - you will then be protected by the 13A fuse in the plug. No different to changing it to a 13A FCU.

 

[BigJock2005]

Well, actually some good news here. Things not as bad as I thought. I've traced the cable back, and what I thought was a spur off the ring main is actually a spur directly from the CU. It's connected via a Hager 32A MCB and there's no other loads on the feed. So I feel a lot more comfortable now just sorting all that cabling, securing the terminations and junction boxes to feed each of the three rooms with a fused switch and double socket.

 

[ban-all-sheds]

what I thought was a spur off the ring main is actually a spur directly from the CU. It's connected via a Hager 32A MCB and there's no other loads on the feed.

Then it's not a spur, is it.

 

[securespark]

Assuming all the cabling will be 2.5, change the MCB for a 25A and run everything as a radial circuit with no need to fuse down (except for lights, where you could fit a FCU).

If it is not (and it does sound a mess) you could rewire as a radial in 4 milli.

You don't have to have a ring final.

It will be notifiable though.