Ring r1 issue.

[Iona222]

Sound mate, hopefully nail it tomorrow.

Hi mate, I've plugged in one end of the circuit and all sockets are working. Strange.

 

[Iona222]

Hi mate, I've plugged in one end of the circuit and all sockets are working. Strange.

There's evidence of a wire snipped.

 

[westward10]

It isn't necessarily strange as the break maybe between the board and first socket. Making one leg of the circuit live to find this fault is poor advice, the best advice is dead continuity tests as previously stated. The circuit may only have a high resistance joint and not a clean break hence the method you tried indicated they are all live, you are a trainee and this was inappropriate advice. A continuity tester may well show open circuit which may mean clean break or a high resistance connection which is above the range your tester it set to. Try an insulation resistance test across the two ends and see if it is clearly open. Either way you need to do cold continuity tests to find the fault.

 

[Iona222]

It isn't necessarily strange as the break maybe between the board and first socket. Making one leg of the circuit live to find this fault is poor advice, the best advice is dead continuity tests as previously stated. The circuit may only have a high resistance joint and not a clean break hence the method you tried indicated they are all live, you are a trainee and this was inappropriate advice. A continuity tester may well show open circuit which may mean clean break or a high resistance connection which is above the range your tester it set to. Try an insulation resistance test across the two ends and see if it is clearly open. Either way you need to do cold continuity tests to find the fault.

I've linked r1 and rn at the board. I'm get around 0.65 at every socket, except one, it's high 1.2 it a spur.

 

[pc1966]

I've linked r1 and rn at the board. I'm get around 0.65 at every socket, except one, it's high 1.2 it a spur.

Is this the figure-of-eight test?

If it look like there is no longer a break in the ring then either it was due to moving the connections at the MCB end (but I would expect you would have noticed a poor clamp, or it gripping the insulation and not wire), or somehow testing with 230V on one leg but not the other has blown away some thin corrosion somewhere and contact is made once more.

That is actually the worst possible outcome as the fault is still present, just no longer showing up on test

 

[brianmoooore]

This is the problem with testing "by the book". The mot important thing when dealing with what may be an intermittent fault is to disturb absolutely NOTHING more than you can help, before you have a good indication of where the fault may be located.
Disconnecting one leg at the MCB and then going around the property with a Voltstick would have disturbed nothing more than the readily accessible and observable at the MCB.

 

[westward10]

Have you redone a continuity test at the ends including an IR test across them.

 

[Iona222]

I've linked r1 and rn at the board. I'm get around 0.65 at every socket, except one, it's high 1.2 it a spur.

I've changed a couple of circuits and I'm getting 5.01 ohms on r1. Least I'm getting continuity.

Have you redone a continuity test at the ends including an IR test across them.

I'm getting 0.55 on rn. 4.5 on r1. I.r. Live to live 500M

 

[westward10]

You can't have 500 MOhm and 4.5 ohm end to end on the lines.

 

[timhoward]

Give the test leads a good squeeze and make sure it's really 5 ohms.
My suspicion is that the loose connection is one you have already touched.
I also suspect you may have linked r1 and rn on opposite legs earlier.

Don't do any more live tests until the dead tests make sense.

 

[pc1966]

I've changed a couple of circuits and I'm getting 5.01 ohms on r1. Least I'm getting continuity.

I'm getting 0.55 on rn. 4.5 on r1. I.r. Live to live 500M

At least it is still present to be found.

Try linking L & N at one end (L & N open on other leg) and go round checking low ohm resistance L-N at each socket, it should be low-ish (0-1 ohm or so) on that side until you get to around the fault and then probably 4 ohm is added.

Then do the opposite (link L-N other leg, open first leg) and see if you find the fault at the same socket.

 

[pc1966]

Then do the opposite (link L-N other leg, open first leg) and see if you find the fault at the same socket.

Just to correct that, you probably will find two sockets where there is a change when checked from both direction. Assuming just the one fault (hmm, yes...) then it will be the link between them that has the high R problem.

If lucky and there is no stupid hidden junction box then probably one of those sockets will be found to have a poor connection / loose screw and correcting that ought to result in r1 & rn being practically identical.

 

[Iona222]

Just to correct that, you probably will find two sockets where there is a change when checked from both direction. Assuming just the one fault (hmm, yes...) then it will be the link between them that has the high R problem.

If lucky and there is no stupid hidden junction box then probably one of those sockets will be found to have a poor connection / loose screw and correcting that ought to result in r1 & rn being practically identical.

Gave up on it, whet round all the sockets. There's a loft but no access. High, fluctuating r1 reading. Least I got it improved from no continuity. My friend just bought the house was good experience like, but wish I was successful on resolving the issue.

 

[brianmoooore]

Open circuit is relatively safe. An open circuit passes no current, so develops no heat.
A resistive joint, like you have now, produces heat in watts to the product of the current flowing through it and the resistance of the fault.
Much more dangerous than it was.

 

[timhoward]

You need to advise your friend to have this looked at or have another go with a clear mind.

 

[Iona222]

You can't have 500 MOhm and 4.5 ohm end to end on the lines.

Thats what I got mate, im not trying to pull the wool like.

 

[Iona222]

You need to advise your friend to have this looked at or have another go with a clear mind.

I've advised him, I took off every socket, what else can I do mate.

 

[westward10]

I've advised him, I took off every socket, what else can I do mate.

Not give up?

 

[Iona222]

Not give up?

I've followed all the advise, he needs to get someone with more experience. If you fancy a drive to Glasgow?.. I didn't get access to the loft to check for cables damaged or so. I could change the rest of the sockets I didn't change. Or than that.

 

[MJPD29]

I've followed all the advise, he needs to get someone with more experience. If you fancy a drive to Glasgow?.. I didn't get access to the loft to check for cables damaged or so. I could change the rest of the sockets I didn't change. Or than that.

Don't give up on the fault. If you can't fault find you'll never be a good spark and many out there can't. Persevere and it'll be worth it there's nothing like hands on experience to learn. I've been there and it's ---- having to do it yourself at the start but you'll be glad you did.