Cut Ring Main

pmartin86

tacpot12 wrote: »

You have now have two cables that are only capable of safely carrying 20A protected by a 32A fuse/MCB. Thus, you could if you plug enough into the longer leg of the ring overload that cable which could lead to a fire.

You can fix the break with a junction box that is accessible - e.g. you could install a backbox with a blanking plate to cover it. Alternatively, if you can pull the cable back from the break to the socket that the fridge is connected to, and if you have spare ways in your consumer unit, you could split the ring into two radial circuits; a short one serving just the fridge, and a longer one serving the rest of the kitchen. There is a school of thought that fridges benefit from being on their own dedicated circuit as a fault on another circuit won't cause the fridge to lose power and spoil your food. Note that creating a new circuit (as above) is notifiable work (under Part P of the Building Regulations).

My understanding was it was about 16A, not 20, might be usefull to know in future

I've never considered a seperate circuit for just the fridge, its and interesting idea, definatly something to ponder for future, the wiring in this house is all realtivly new (3~ years) so won't be doing it right now...but definatly a good idea for the next house.

Ectophile

Leaving aside all the melodramatic "it will burn your house down" replies...

You've got two options to make it good.

1. Disconnect the broken cables at their origin (the next accessory round the ring). Replace the 32A breaker (or 30A fuse) with a 20A one.
2. Repair the cable. Repairs must either be maintenance-free, or screw terminals that are accessible (e.g. behind a blanking plate).

Typical maintenance-free terminations could be crimps, made off with a proper crimping tool (not a cheap nasty one), and then sleeved with further insulation. Alternatively, something like Wago terminals, in a Wagobox. It helps if you can pull through some slack to make off the connection.

missile

Just a suggestion .............. You may be able to install a socket where you have cut the ring main?

pmartin86

Ectophile wrote: »

Leaving aside all the melodramatic "it will burn your house down" replies...

You've got two options to make it good.

1. Disconnect the broken cables at their origin (the next accessory round the ring). Replace the 32A breaker (or 30A fuse) with a 20A one.
2. Repair the cable. Repairs must either be maintenance-free, or screw terminals that are accessible (e.g. behind a blanking plate).

Typical maintenance-free terminations could be crimps, made off with a proper crimping tool (not a cheap nasty one), and then sleeved with further insulation. Alternatively, something like Wago terminals, in a Wagobox. It helps if you can pull through some slack to make off the connection.

Thank you, this is the sort of advice I was after!

I'd like to keep the ring, so weill be looking at a repair, I've ordered one of the following:

https://www.amazon.co.uk/Ashley-J803-Maintenance-Terminal-Junction/dp/B00BATALJK

It appears to be whats required, are you able to confirm this is correct?

As for the crimping and insulation, I didn't thik that would be suitable, I've got some of these left over from a hobby project (Home made garden trommel powered by an old drill - Dont even START of the safety of that one... ) along with various lengths of heatshrink, would that be suitable? I can see the red connector can handle cable width of 1.5mm, but i wasnt sure about the load, would 1 per core (1 live, 1 earth and 1 neutral) plus electrical tape + heatshink be sufficent?

pmartin86

missile wrote: »

Just a suggestion .............. You may be able to install a socket where you have cut the ring main?

Unfortunatly not..I've cut it in the most awkward spot possible...I'm clever like that!

Heedtheadvice

That Ashley box is fine.
I was going to suggest an additional socket too but as you say not possible.

Beware crimps. Those you mention are great combining a secure connection, seal and support but not for your purpose.
They do not provide an overall sheath for the cable (heat shrink could be fine but then the heat to shrink might damage the original cable sheath) and many a crimp terminal is only suitable for stranded wire, not solid as I expect your ring main will be.

Head_The_Ball

missile wrote: »

Just a suggestion .............. You may be able to install a socket where you have cut the ring main?

pmartin86 wrote: »

Unfortunatly not..I've cut it in the most awkward spot possible...I'm clever like that!

If an additional socket would be useful not too far away from where you have broken the ring circuit, you could look at rerouting the ring circuit or running a spur socket while you are repairing the damage without adding too much extra work to what you have to do anyway.

In my experience, you can never have too many sockets in a kitchen.

Make sure you don't exceed the maximum length of the ring circuit.

Is it a solid wall or a stud wall?

pmartin86

Head_The_Ball wrote: »

If an additional socket would be useful not too far away from where you have broken the ring circuit, you could look at rerouting the ring circuit or running a spur socket while you are repairing the damage without adding too much extra work to what you have to do anyway.

In my experience, you can never have too many sockets in a kitchen.

Make sure you don't exceed the maximum length of the ring circuit.

Is it a solid wall or a stud wall?

Basicly its between 2 double sockets at different heights on the side of a chimney breast, the alcove has shelving in it which is used for microwave/toaster etc, theres allready a double socket to each shelf which is more than enough, when i did it i was hoping that I had cut the wiore between 2 sockets, but unfortunatly i cut the long wire that goes from the bottom socket back to the celing void and accross the room to the other side, typical!

Wall is solid brick (as is the entire house, dont build em like this anymore!) with dot and dab board and a plaster skim.

pmartin86

Heedtheadvice wrote: »

That Ashley box is fine.
I was going to suggest an additional socket too but as you say not possible.

Beware crimps. Those you mention are great combining a secure connection, seal and support but not for your purpose.
They do not provide an overall sheath for the cable (heat shrink could be fine but then the heat to shrink might damage the original cable sheath) and many a crimp terminal is only suitable for stranded wire, not solid as I expect your ring main will be.

Correct, it's solid core. I'll wait for the box to arrive then, no point in rushing it and getting a half-assed job.

Ectophile

pmartin86 wrote: »

Thank you, this is the sort of advice I was after!

I'd like to keep the ring, so weill be looking at a repair, I've ordered one of the following:

https://www.amazon.co.uk/Ashley-J803-Maintenance-Terminal-Junction/dp/B00BATALJK

It appears to be whats required, are you able to confirm this is correct?

As for the crimping and insulation, I didn't thik that would be suitable, I've got some of these left over from a hobby project (Home made garden trommel powered by an old drill - Dont even START of the safety of that one... ) along with various lengths of heatshrink, would that be suitable? I can see the red connector can handle cable width of 1.5mm, but i wasnt sure about the load, would 1 per core (1 live, 1 earth and 1 neutral) plus electrical tape + heatshink be sufficent?

It says it's maintenance-free, and suitable for 32A, so that's right. The advantage of MF boxes is that you are allowed to bury them - no access panels are required.

If crimping, you'd need ones suitable for 2.5mm cable. Then oversleeve with something.