Is this a spur?

[taylor414]

I wanted to spur from a socket to a 13amp FCU and onto two additional in line single sockets.

When I inspected the socket i wanted to spur from, it had two cables running into it but I felt it was a later installation than other sockets on the ring.

I wondered if it might be an intermediate outlet on a two outlet spur - so disconected the live wires and switched the power back on wondering if i would find one additional dead socket , but didnt. All other sockets in the house were live. I then checked sockets in the locality so see if I could find a spur running from them but couldnt. I also checked that the socket in question was controlled by the socket circuit breaker on the fuse board and it was.

I want to confirm the status of this socket ( ie is it a spur or not) so am I doing something wrong??

 

[333rocky333]

If it is a ring, both cables when parted with the socket removed, will be live

 

[Taylortwocities]

Be careful, this involves working with live conductors!

Turn off the power

take out the two live (red conductors). Put terminal blocks on each end to insulate them.

Turn power back on

using a test instrument or multimeter (not a neon screwdriver) test between neutral and each of the exposed conductors.

If you measure 230V on both then its a fair bet that the socket is on a ring and not a spur that has been spurred from.

 

[taylor414]

Thanks for the replies.

That was about to be my next question - how to safely test if they are live ?

If I do this test and both are live, would I be ok at that point to proceed with a fused spur?

 

[Taylortwocities]

Yes

 

[taylor414]

Thanks again

 

[333rocky333]

That was about to be my next question - how to safely test if they are live

Ideally with a voltage tester otherwise
Isolate and Remove reds only from socket put one red in connector block connect one live only into the socket ,reset and test socket,
Isolate and repeat with other red only connected in socket and other sealed off ,
That will prove if live both times, that the circuit live at least is a ring,
the N and E should be a ring also but that you cannot check without more detailed testing
Remember to isolate each time and seal unused red each time

 

[taylor414]

Was just pricing up a multimeter in the screwfix catalogue ( the cheapest being only £6 or £7) . However I think I will try the individual lives in the socket first - as described.

like a lot of DIY'ers I presently only have the test neon screwdrivers. Electricians dont seem to place much faith in them. Why is that?

 

[Softus]

like a lot of DIY'ers I presently only have the test neon screwdrivers. Electricians dont seem to place much faith in them. Why is that?

1. They give only the very roughest of indications of a voltage being in the ball park of 240V.

2. They are capable of making your hand become part of a circuit that delivers a lethal shock to you. For example, if you didn't notice that the tool had become filled with water.

3. The neon, if it glows only weakly, could appear to be not glowing, such that the conductor that you think is dead is instead still live.

 

[333rocky333]

Just be carefull and isolate ,and treat as live even when circuit is off by avoiding unneccessary touching of the copper cores just in case,

I think some of the neons are not rated highly as there is always a possibility of internal failure, and possibility the live could pass through to the end you touch, some light up for other reasons and just appear to be misleading.
I personally do not rate the cheap multimeters on live eguipment as the prongs are not always well insulated and sometimes too long increasing the chance of shorting to something,

 

[taylor414]

thanks to everybody for the sound advise

 

[Lectrician]

You should never need to test this live!

Isolate power, test for dead.

Check continuity of the ring at the socket using low ohms on your meter.

Working live when you do not need to, especially a DIY'er, is not the best advice to give...

 

[roberta1000]

Agreed, daft to check live when this is clearly easy to check dead. Also this allows a (resonable) check that the neutral and earth rings are also continuous.

Re neons - it can take as little as 40V or so to make a neon glow so quite easy to get a false positive from inductive pickup. If you don't put your other hand on an earth it might not light well enough on 230V to notice (especially in sunlight). If anything goes wrong with the screwriver or if it has a coating of something conductive you might get a jolt which even though slight might cause you to jump and get a real belt.

 

[taylor414]

You should never need to test this live!

Isolate power, test for dead.

Check continuity of the ring at the socket using low ohms on your meter.

Would you be able to explain this again for me - ie test for dead and then do a continuity test.

Im going to buy a cheapish multimeter today but have never used one before.

Many thanks

 

[ban-all-sheds]

Take a look at this: http://www.beha.com/files_d/sets/1333.pdf

Looks ideal for a household starter set - multimeter, voltage indicator and dedicated continuity tester, all in a handy case.

Couldn't find details of the set in English, but all 3 individual instruments are listed.

http://www.beha.com/files_uk/multimeter/93549.pdf

http://www.beha.com/files_uk/voltagetesters/6741.pdf

http://www.beha.com/files_uk/continuitytesters/9023.pdf


Also see another discussion here: //www.diynot.com/forums/viewtopic.php?t=26282