What type of circuit in my kitchen?

[elsmandino]

Hi there - sorry, I know that this issue has probably been discussed to death but my research has left me with conflicting answers and I would be really grateful for some clear advice on here.

My house is pretty old (1930s bungalow) and it is a bit of mishmash - there are two circuits for the lights (once with an earth and one without).

There are also three power circuits as well:

1. Ringmain that covers the livingroom and two bedrooms.
2. A separate circuit just for a third bedroom
3. A separate circuit just for the kitchen

Is there any way I can work out whether the second and third circuits are ring or radials?

My kitchen has a lack of sockets at the moment and I would love to add more but need to know what I am dealing with, first.

 

[jurassic sparkk]

Is there any way I can work out whether the second and third circuits are ring or radials?

Take off a socket and meter in continuity. Check between Live and live. Neutral and neutral. CPC to CPC. If it's a ring your meter will beep with a low resistance. However, if it's a radial meter will show OL. (Power off of course while doing these tests.)

What are the protective devices current rating? Size of the conductors?

What exactly are you planning to do?

 

[ericmark]

@jurassic sparkk is correct, in the main ring finals are 30 or 32 amp, you can get a 32 amp radial, but in the main they are less, in 1966 the rules changed on earths to lights, at about the same time we went from rubber to plastic insulation on wires, so if no earth on some lights you need an EICR (electrical installation condition report) with some urgency.

 

[Harry Bloomfield]

Is there any way I can work out whether the second and third circuits are ring or radials?

Look at the consumer unit, 32amp MCB's would suggest a ring, though you can have a 32amp radial. Check inside the consumer unit, (if you feel safe to do that) - two 2.5mm wires connected to the MCB, would further confirm a ring, though again not absolutely certain. Disconnecting the two wires, and confirming continuity between the adds more certainty it's a ring.

 

[EFLImpudence]

Look at the consumer unit, 32amp MCB's would suggest a ring, though you can have a 32amp radial. Check inside the consumer unit, (if you feel safe to do that) - two 2.5mm wires connected to the MCB, would further confirm a ring, though again not absolutely certain.

Decisive help.

Disconnecting the two wires, and confirming continuity between the adds more certainty it's a ring.

You would think someone else would have said that already.

 

[jurassic sparkk]

Check inside the consumer unit, (if you feel safe to do that)

Not a very good suggestion, especially if the OP doesn't have a mains isolator fitted.

 

[Harry Bloomfield]

Decisive help.


You would think someone else would have said that already.

No help at all, from you, so I do wonder - why bother to comment at all?

 

[Murdochcat]

Once you have found if it’s a ring or not, what is your plan ?

 

[elsmandino]

Thanks so much for the responses, everybody - annoyingly, I didn't have time to have a look at this, last night, but shall have a look at the weekend.

As suggested, my first port of call is to take the front off the consumer unit and see how many sets of wires there are for each of the three sockets - if I see one, at least I can say that that is definitely a radial. If I see two, I know that it could be a ring or two radials, so I will have to do further testing.

Just to confirm what I am up to:

1. My kitchen has two double sockets and a single on the wall (all above the counter). I need to add some additional sockets and needed to know where I can run these from (i.e. to avoid spurs from spurs). I could, however, just upgrade all three to triple sockets but am not sure if that is good practice or not.

2. My third bedroom (currently used as an office) has a single and a double socket in it, with the double socket being located on a stud wall. On the other side of that wall is my corridor, which has no sockets in it. I was hoping to run a spur from the socket to the other side of the wall, to give me some power there - is that permissible? Again, I wanted to check exactly what type of circuit I was dealing with before doing anything.

 

[jurassic sparkk]

Thanks so much for the responses, everybody - annoyingly, I didn't have time to have a look at this, last night, but shall have a look at the weekend.

If I see two, I know that it could be a ring or two radials, so I will have to do further testing.

Or a ring/radial with a spur.
IMHO, testing at a socket with a multimeter will be much easier.

Just to confirm what I am up to:

1. My kitchen has two double sockets and a single on the wall (all above the counter). I need to add some additional sockets and needed to know where I can run these from (i.e. to avoid spurs from spurs). I could, however, just upgrade all three to triple sockets but am not sure if that is good practice or not.

Probably not. What are you running in the kitchen?

2. My third bedroom (currently used as an office) has a single and a double socket in it, with the double socket being located on a stud wall. On the other side of that wall is my corridor, which has no sockets in it. I was hoping to run a spur from the socket to the other side of the wall, to give me some power there - is that permissible?

Yes just make sure all cables run in safe zones.

Again, I wanted to check exactly what type of circuit before dealing on it.

A picture of the consumer unit would help.

 

[ebee]

Well it quite possibly is feaseable either ring or radial. If you have adequate knowledge to do it safely you could trace the connections in order to establish the equivalent circuit on paper and make decisions accordingly but might be advisable to have an EICR (Periodic) inspection done by someone qualified and better equipment than DIY. Then you know you are up against. A properly qualified inspector should be able to advise accordingly and would make other tests you might not have even considered. You then might follow their advice or even ask them to undertake it for you. The lack of earthing is a red flag for a start.

 

[JohnD]

A good first move would be to provide a new circuit, to modern standards, to the kitchen. Kitchens need quite a lot of outlets, I recommend a row of sockets and switches about 150mm above the worktop, all along the walls and preferably all around the room. A double socket every metre is not too many, and plenty of appliance switches, even if you have not yet got a dishwasher, tumble drier etc.

This is economical in time, effort and materials, since you mostly only need to make one major chase, with spurs running up and down for the switches to outlets for cooker hood, wall lights, boiler, undercounter appliances such as dishwasher, fridge etc.

In the old days we would have used a ring, but modern practice would be to use a 4mm radial. Either is permitted.

It would also be best to run a separate radial for an electric cooker, even if you are currently using gas. It is much more upheaval to add one later.

Since you have an old installation, this could be done independently of your old CU, using a modern fireproof metal CU fitted with an RCBO for each circuit. You will be wanting to renovate your other circuits as well, so get a good big one, 12-way or so, for future work. The extra cost of a large empty metal box is not much more than the cost of a small empty metal box.

Fitting a new CU is a job for a professional electrician. He or she will probably also need to upgrade your earthing and bonding. Your old circuits will probably be too old to connect to the new CU but can be left separate if you are not yet ready for a whole house rewire.

If you are handy you can cut out the chases and boxes depending on your agreement with the electrician. I find it easy to cut and mortar them in, but I am quite experienced. It is dirty, dusty work though a professional will (should) have tools with vacuum dust extraction.

 

[ericmark]

The ring final can have spurs (unfused and fused) and to find out which needs some testing, in the main looking is not good enough, as some one in the past may have not followed the rules, so we have to test.

The regulations say we don't need to upgrade, but any new install must comply, and this is the main problem with old wiring, we can continue to use a non 30 mA RCD protected socket, or have a non 30 mA RCD protected cable in the wall, but to add to it, the new stuff needs the 30 mA RCD protection.

I say 30 mA as old installations often had 100 mA or 300 mA RCD's, which are no longer considered good enough.

I had this problem with my dad's house, to add I would need to use Ali-tube cable and RCD sockets as no RCD fitted, and the state of the wiring would not allow an RCD to be fitted to protect all, the house needed a rewire, which my dad would not allow, it was done after he died, but my dad thought he knew it all, and had done some very dodgy work. Sorry to say this is common with old homes.

The other problem is the standard multi-meter is not really good enough, to test low ohms we should pass at least 200 mA, and to test insulation normally 500 volt, although can use 250 volt, we can't really time 40 mS for testing RCD's without a special tester, and to measure loop impedance is extremely hard and needs a lot of maths without a loop impedance tester.

So we as DIY tend to trust to the Lord, we can do simple tests with a multi-meter, but select the wrong range on most and we can have a big bang, the type I bought my son many years ago has no wired amp range, so reasonably safe, and it will give one a reasonable idea what is going on, but one still needs to know how to use it, the one shown cost me £35 so not too expensive, however to learn how to use it on a forum is unlikely to work very well.

The insulation tester also cost me £35 for cheapest I could find new, but again it does produce 1000 volts, although can be set to 250 or 500 volt, but I would not likely to try and explain how to use one without being on site. I well remember an 'A' level physics class and how many students managed to blow the fuse in the multi-meters issued. 'A' it seems stands for advanced, but they seemed to have less know how to when I did my 'O' levels.

So what we need to do is assess how much you know, and if safe for you to attempt DIY. Can you recognise crumbling rubber insulation? It can so easy be a case where fools rush in where angles fear to tread. However pictures always help. One gets a far better idea of what one is dealing with when one sees pictures.

(once with an earth and one without)

I assume it should say one not once, but it rings alarm bells for me, and I wonder what state wiring is in the start with? To not have an earth to lights, means pre-1966, so would a 1930s bungalow have been rewired in 1966? when only 36 years old? So seems likely some very old wiring, likely old fuse boxes like these and the ring final system only came out post WW2 so may be even older, it may even have the old ELCB-v fitted, and so hard for DIY to work out the difference. I have posted this picture so many times as people have not realised what they have. So to start with lets see some pictures, one picture can be worth a 1000 words.

 

[ericmark]

@JohnD idea is good, my dad had this fitted at the door of his kitchen fed with steel wire armoured cable from main consumer unit to supply his new kitchen so only kitchen was rewired. Some times one has to think out of the box.

 

[elsmandino]

Just uploading a pic of my consumer unit as suggested. Interestingly, all three circuits are protected by 32A breakers.