Little help identifying cable colours.

justinmg1

Hi all, wonder can anyone shed some light on an issue for me. I have an underground cable running to my shed to give power. It was installed some many years ago and I’m doing some upgrades.

There are 4 wires coming from it, red black blue and yellow.

I’ve identified that the red is live, black is neutral...

Can anyone tell me is the yellow or blue the earth?

Cheers all

ZENER

Have you tried measuring between the RED and YELLOW and see if there's voltage ? It there any armour on the cable ?

Ken

2011

justinmg1 wrote: »

There are 4 wires coming from it, red black blue and yellow.

Any colour could be anything. Without testing the cables you have no way of knowing for sure.

Back in the 90's it the convention was:
Red was the first phase
Yellow was the second phase
Blue was the third phase
Black was neutral
Green / Yellow was earth

I doubt that you have a three phase supply, but so far your description aligns withe the above.

Can anyone tell me is the yellow or blue the earth?

Earth should still be green / yellow but in this case you will have to test to know for sure. Perhaps there is no earth?

justinmg1

Thanks for the replies, I don’t have a phase tester but have a good knowledge of wiring without going into big detail. What threw me is the 4 wire combination in the cable plus the colour combination. The cable is steel sheethed too. As I mentioned it was laid previously, there is a light in the shed but I’d like to branch off and run power to have a tumble dryer but would like to have an earth connected for that purpose

Edit: I should have noted that the power supply is coming from ceiling lights in house and has a wall switch to turn power on/off

Luckysasha

justinmg1 wrote: »

Thanks for the replies, I don’t have a phase tester but have a good knowledge of wiring without going into big detail. What threw me is the 4 wire combination in the cable plus the colour combination. The cable is steel sheethed too. As I mentioned it was laid previously, there is a light in the shed but I’d like to branch off and run power to have a tumble dryer but would like to have an earth connected for that purpose

Sounds like you know what your talking about alright !! Called an electrician for everyone’s safety

justinmg1

@luckysasha, when I mentioned a good knowledge that should have been “good basic knowledge” I know enough to understand that there is power running to the shed for lighting which is 2 phase from the junction box with yellow and blue wiring not used. I want to replace the 2phase cable in the shed and replace with 3 phase cable

aido79

justinmg1 wrote: »

Thanks for the replies, I don’t have a phase tester but have a good knowledge of wiring without going into big detail. What threw me is the 4 wire combination in the cable plus the colour combination. The cable is steel sheethed too. As I mentioned it was laid previously, there is a light in the shed but I’d like to branch off and run power to have a tumble dryer but would like to have an earth connected for that purpose

Edit: I should have noted that the power supply is coming from ceiling lights in house and has a wall switch to turn power on/off

Either forget about the tumble drier or forget about using this cable for power to your shed and run a new cable.
Do you seriously claim to have a good knowledge of wiring and think it's ok to run a tumble of a lighting supply?

justinmg1

aido79 wrote: »

justinmg1 wrote: »

Thanks for the replies, I don’t have a phase tester but have a good knowledge of wiring without going into big detail. What threw me is the 4 wire combination in the cable plus the colour combination. The cable is steel sheethed too. As I mentioned it was laid previously, there is a light in the shed but I’d like to branch off and run power to have a tumble dryer but would like to have an earth connected for that purpose

Edit: I should have noted that the power supply is coming from ceiling lights in house and has a wall switch to turn power on/off

Either forget about the tumble drier or forget about using this cable for power to your shed and run a new cable.
Do you seriously claim to have a good knowledge of wiring and think it's ok to run a tumble of a lighting supply?

Cheers for that, Question answered. It is a new place for me and don’t know where the feed to the shed is being taken from but I was informed that it is geared to install power sockets in the shed

TheChizler

Best case you trip the MCB or blow a fuse, worst case you start a fire in your house. Please don't do this. A lighting circuit doesn't have the capacity for the current needed by a tumble dryer, the cables in the walls or ceiling would overheat and potentially cause a fire.

The run down to the shed used may be suitable for the load but you need to ensure its hooked up to an appropriate supply and the shed circuits are separated into lighting and sockets.

gctest50

justinmg1 wrote: »

Cheers for that, Question answered. It is a new place for me and don’t know where the feed to the shed is being taken from but I was informed that it is geared to install power sockets in the shed

Don't believe any of that unless you enjoy house fires

Go find both ends of the cable and have a look along it

1. see if it's in good condition

2. check what size it is

3. see what it's connected to at each end

justinmg1

TheChizler wrote: »

Best case you trip the MCB or blow a fuse, worst case you start a fire in your house. Please don't do this. A lighting circuit doesn't have the capacity for the current needed by a tumble dryer, the cables in the walls or ceiling would overheat and potentially cause a fire.

The running down to the shed used may be suitable for the load but you need to ensure its hooked up to an appropriate supply and the shed circuits are separated into lighting and sockets.

Perfect! As aido said I’m going to give it a miss. Think I was duped by advise given that it was wired to take power sockets (3phase) what convinced me was the 4phase cable running to it.

justinmg1

To all of you who replied have to thank you all, gonna give it a miss and get someone in. I know internal lighting runs a lot less power and from what I can see flipping trip switches the power is coming from ceiling supply running out to the shed but they used a really high power cable to run out to the shed with an outside junction box and lighting coming from that.

TheChizler

It's absolutely worth getting someone in to see if it's feasible. Sockets in sheds are invaluable! Best of luck with it.

Luckysasha

My god you obviously have a good basic knowledge of 2 phase and 4 phase Lighting circuits that can supply a tumble dryer. Get an electrician before you burn your house down

confusedeire

Can't people just help the guy out with out being sarcastic and belittling.

We all know a little knowledge of electricity is a dangerous thing. But a little bit more will help him.

The cable could be switched by an switched fuse spur in the house capable of powering sockets already on an RCB. We don't know because of the ℹinformation given.

I think if you can't trace the cables back to where there fed from and the cable size its best to get a professional in. They can tell if its safe to power sockets off it fairly quickly and get you up and running.

justinmg1

confusedeire wrote: »

Can't people just help the guy out with out being sarcastic and belittling.

We all know a little knowledge of electricity is a dangerous thing. But a little bit more will help him.

The cable could be switched by an switched fuse spur in the house capable of powering sockets already on an RCB. We don't know because of the ℹinformation given.

I think if you can't trace the cables back to where there fed from and the cable size its best to get a professional in. They can tell if its safe to power sockets off it fairly quickly and get you up and running.

Thanks for the reply, I apreciate the feedback, as you mention coming here was to get help and not criticised. Instead of going and wiring it up I sought some honest feedback. Maybe I did not give enough information as you mention with trying to explain how the wiring appears and was my pitfall, all I know is there is heavy duty cabling running to the shed and is power is turned on/off via a wall mounted switch in the kitchen. As I mentioned I was advised by previous owner that the cable is all ready there to run power sockets.

confusedeire

justinmg1 wrote: »

Thanks for the reply, I apreciate the feedback, as you mention coming here was to get help and not criticised. Instead of going and wiring it up I sought some honest feedback. Maybe I did not give enough information as you mention with trying to explain how the wiring appears and was my pitfall, all I know is there is heavy duty cabling running to the shed and is power is turned on/off via a wall mounted switch in the kitchen. As I mentioned I was advised by previous owner that the cable is all ready there to run power sockets.

Steel wire armoured cable can look large due to the metal armour and the extra plastic protection. But the conductors inside can be quite small. It is usually written on the outer layer of the cable. Sumthing like 4X2.5mm2. This means 4 cores(cable) by 2.5mm2 core size. Absolute minimum for socket is 2.5mm2. But it depends on the length of the run of cable to the shed.

justinmg1

Thanks confusedeire for the feedback I was looking for, the problem I have is the underground cable running to the shed is under paving so I’d have to lift the whole paving to trace it back to its source feed from the house.

I understand what you mean by the cores and am happy they are sufficient, they are thick steel twist looking. To try explain they could not be used in a household plug as they are too thick.

This cable is running into an outdoor weatherproof junction box. Within that there is a simple 2phase cable connected up to the live and neutral that feeds into the shed to supply a light.

What I’d like to do is run an additional branch from this junction box to power sockets on the wall for the tumble dryer but although criticised previously I understand that if the power feed from its source in the house is connected through a lighting feed that is my concern.

The feed length in only 5/6meters

Edit; the internal switch I mentioned on the wall, I identified the trip switch for it and it also disabled Allen the ceiling lighting in the hall and kitchen so I do think it is on that feed

TheChizler

justinmg1 wrote: »

This cable is running into an outdoor weatherproof junction box. Within that there is a simple 2phase cable connected up to the live and neutral that feeds into the shed to supply a light.

Any chance of a pic of this as it is right now?

FYI one live and one neutral is called a single phase supply.

confusedeire

justinmg1 wrote: »

Thanks confusedeire for the feedback I was looking for, the problem I have is the underground cable running to the shed is under paving so I’d have to lift the whole paving to trace it back to its source feed from the house.

I understand what you mean by the cores and am happy they are sufficient, they are thick steel twist looking. To try explain they could not be used in a household plug as they are too thick.

This cable is running into an outdoor weatherproof junction box. Within that there is a simple 2phase cable connected up to the live and neutral that feeds into the shed to supply a light.

What I’d like to do is run an additional branch from this junction box to power sockets on the wall for the tumble dryer but although criticised previously I understand that if the power feed from its source in the house is connected through a lighting feed that is my concern.

The feed length in only 5/6meters

Edit; the internal switch I mentioned on the wall, I identified the trip switch for it and it also disabled Allen the ceiling lighting in the hall and kitchen so I do think it is on that feed

The best bet is to take pictures and put them up here. Pictures of the wiring in the shed. The junction box and the switch for the shed.

justinmg1

[/QUOTE]
Any chance of a pic of this as it is right now?

FYI one live and one neutral is called a single phase supply.[/quote]

Cheers all, I’ll do just that

aido79

justinmg1 wrote: »

I’d have to lift the whole paving to trace it back to its source feed from the house.

No you wouldn't. A multimeter can be used to trace the cable very easily if you can find both ends of the cable.

Luckysasha

Or you could just get a spark in who knows what he is doing

red sean

Luckysasha wrote: »

Or you could just get a spark in who knows what he is doing

And it would be safer too!
When someone talks about 2phase and 4phase systems they are clearly out of their depth.

justinmg1

aido79 wrote: »

justinmg1 wrote: »

I’d have to lift the whole paving to trace it back to its source feed from the house.

No you wouldn't. A multimeter can be used to trace the cable very easily if you can find both ends of the cable.

Thanks aido79, that’s the problem in itself. I do not know where the feed is coming from the house per sey. I know where a feed is running into the light switch but from there it runs externally I dont

justinmg1

@redsean I’m not here to be criticised or belittled, I’m here for advise and a little more education. I never claimed to be an electrician, I simple stated that I have a good basic knowledge, nothing more. My interpretation or phrasing of 2 phase etc is educated from past and have since been educated a little more by thechizler which I thank very much

aido79

justinmg1 wrote: »

Thanks aido79, that’s the problem in itself. I do not know where the feed is coming from the house per sey. I know where a feed is running into the light switch but from there it runs externally I dont

An electrician will be able to figure out where the cable is fed from without disturbing the paving. It would be madness to touch the paving in my opinion.

justinmg1 wrote: »

@redsean I’m not here to be criticised or belittled, I’m here for advise and a little more education. I never claimed to be an electrician, I simple stated that I have a good basic knowledge, nothing more. My interpretation or phrasing of 2 phase etc is educated from past and have since been educated a little more by thechizler which I thank very much

I'm not criticising you so please don't take offence but you might want to stop claiming to have a good basic knowledge as you have shown that this isn't the case by other things you have written.
2 phase systems do exist but they are more than likely very different from what you seem to think they are.
As has been said already..a little knowledge is a dangerous thing. Anyone can wire something up especially if it's lights and sockets but electricians do a 4 year apprenticeship to ensure they are aware of safe practices, correct cable sizes and breaker ratings etc.
As suggested already leave it alone and call an electrician.

justinmg1

Thanks all for your feedback, any moderators can now close this off. Thanks again, electrician called!

2011

justinmg1 wrote: »

Thanks all for your feedback, any moderators can now close this off. Thanks again, electrician called!

Done.
Good luck with it.