High r1 on ring

[m4tty]

Hi,

Tested a board this morning before Im changing it tomorrow or Wednesday.

End to Ends.

r1 - r1 = 620 ohms

rn - rn = 0.41 ohms

r2 - r2 = 0.96 ohms

The house has one ring circuit for whole house. Total 15 single sockets.

Whats the best/quickest way of finding the high resistance. Long lead from legs at board? Then split her ring?

Thanks

Matt

 

[Lee321]

hunch it. i'd go for the high loaders first washing machine/dish washer/kettle

you'll not know how its wired so finding half way which leg etc will be grrrrrrr

or connect 1 r1 to n1 then test between L&N at every socket until you get 620 ohms. it will be that socket or the one before (or atleast the link )

not forgetting could even be a JB or connectors:innocent under floor boards betwen sockets ray

crap pic was done on phone

 

[Doc Hudson]

Have you tried doing a Zs at all sockets? a high r1 may well show up with high Zs around some sockets? Was everything unplugged from the circuit? It could be a broken r1 but reading through some appliances with r1 - rn through equipment bridging a break? I think Lee's suggestion, strapping at board and measuring r1-rn around the circuit would be easier than long leads.

Doc H.

 

[Lee321]

Then split her ring?Matt

only if she's up for it:slap

 

[m4tty]

Lol. Do you recon 620 ohms could be one socket screwed down on the insulation?

 

[Lee321]

loose connection/burn up matty

 

[S60TEM]

I would visually inspect behind all of the sockets and check the tightness of the terminations. As there's only 15 of them it shouldn't take too long, then if nothing shows up as being obvious i'd go for what Lee has suggested.

 

[tom1]

had a similar one a bit back, it was 99k ohms turned out to be a socket screwed down on the insulation. the two cores insulation had melted together

---------- Post Auto-Merged at 23:35 ---------- Previous post was made at 23:20 ----------

http://www.talk.electricianforum.co.uk/question-answer-board/11382-end-end-high-resistance.html

post 2 and 5, sorted it.

although the fault was between a socket 500mm to the left of the cu on kitchen ring, i replaced the cable, only to get a call back few weeks later that upstairs scocket was not working and thats were i found the fault, cut the cable reterminated and then undid the work i did few weeks earlier:Blushing:slap

 

[Theorysparky]

Had a high zs last week 350 ish

socket was corroded from a bathroom leak

i would zs the lot or half split with wander lead and do your R1 again

 

[SPECIAL LOCATION]

I have had a few jobs with either..

1/ external walls with a Damp problem..

2/ internal walls where socket fronts were put io before plaster fully dried..

Both cases Damp working along cables to screw terminal joint's in back of sockets...

Giving some High Res values!

All needed cutting back and re-terminating!"

 

[sellers]

you may not have ring continuity on the live conductor at all.

Imagine if you have 2 310ohm appliances plugged in on both sides of the break.

you measure down the line through the appliance onto the neutral bypassing the break back through the next appliance onto the line back to your tester. Try it with all appliances unplugged and if still 620ohms then its more than likely high resistance joint.

 

[Lee321]

fair point Mr S. a quick ir will show any loads

 

[m4tty]

There was definitely nothing plugged in as I ir'd it and got >299 but am going back all this week and next so will had a good chance to find this. Will let you know how I get on. Thanks for help everyone

 

[Lee321]

So did you show the ring who's boss today Matt ?