One leg of ring main low ohms between all conductors

martinxxxxxx · 2 Dec 2009

Went to a customer today as her fuse (rewirable 30A) on downstairs ring was blowing with a flash.

After a bit of tracing in the terrace house I found that the ring went from socket to socket to the furthest point away from the cu (which is by the front door) to the kitchen. All interconnections to this point passed ir testing and continuity. However the return leg from this point has 0.003Mohm on the ir test.

This run is along a party wall to the next door property that have recently undergone renovations.

I don't think anything they could reasonable do would effect my customers installaton. but I wonder what has become of the this cable run.

Rats? Next door tapping in? a hidden flooded junction box?

I can't get tot the cable as new parkae flooris laid over floorboards. I have requested that it is lifted and I will replace the run. In the meantime I have derated the fuse to 15A and left it as a radial.

Any ideas on the damage to the cable. Oh and one more fact. there is continuity from one end of the cable to the other so it is not snapped.

Answers on a forum please

JBPElectrics · 2 Dec 2009

New sockets sunk into party wall, then screwed/pluged, gone through your clients ring?

Nip next door to find out where it is and hopefully you wont need to pull the floor up.

flameport · 2 Dec 2009

martinxxxxxx said:
I can't get tot the cable as new parkae flooris laid over floorboards.

Have you looked under the floorboards in another room, or under the stairs? Lots of houses have a significant space under the floorboards, so it may be possible to get access via another room.

martinxxxxxx · 3 Dec 2009

Have brought a Locat Cable tracer from RS number 212-152. Looks like I can put it in series with the the live and the signal will disappear where the fault is.

Will go back the job next week now.

They would have to be very long screws to transverse a 9" cavity wall.

The flooring will be coming up as it has just been laid. There fore not fully settled and bit of spare are still around to replace any damaged bits

Martin

JBPElectrics · 3 Dec 2009

Ah, I am too used to victorian terraces with no cavity between....DOH

ricicle · 3 Dec 2009

martinxxxxxx said:
Any ideas on the damage to the cable.

new parkae flooris laid

ban-all-sheds · 3 Dec 2009

martinxxxxxx said:
Have brought a Locat Cable tracer from RS number 212-152.

I hope you bought this: http://cgi.ebay.co.uk/LOCAT-220-cab...ItemQQimsxq20091126?IMSfp=TL091126202005r2491 and not the full price jobbie from RS - you'll never get the cost back.

martinxxxxxx · 3 Dec 2009

"Congratulations martinxxxxxx! You bought this item.
Buyer view
Item:LOCAT 220 cable tracer/fault finder....VERY LIGHT USE"

I wonder if I will ever make the cost back on any of the tools and equipment I have brought in the last few weeks. Each job I do seems to earn me £100 and cost me £200 in new tools. But once you have them you have them (unless someone nicks them out of the van, my worst secret fear of all

)

But you need the tools to do the job efficiently, I was going to buy one of the 20 quid telephone trace jobs, then I saw this and thought it looks a pucker bit of kit for 30 quid extra and will solve this problem fast = I'll have it, never mind that I charge by the hour so it is my customer who will really benefit from the investment.

I will go back on Monday and have a look under them there floorboards armed with my tracer. I also have another job in London which it will help me work out some fuse-finding for a shared building. Actually I don't want this job anymore now I am busy. I quoted £1600 for it and the client only wants to pay about 12. I would pass it on to someone nearer to central London for a consideration. There are 12 c/u to be surveyed, then replaced, the initial price is for the surveys/pirs. Obviously whoever does them will get to do the replacements. [email protected]

martin

martinxxxxxx · 3 Dec 2009

ricicle said:
martinxxxxxx said:

Any ideas on the damage to the cable.

new parkae flooris laid

Click to expand...

they slot together, don't they? ie no nails?

RF Lighting · 3 Dec 2009

No I'm no expert, but I'd expect a parquet floor to be adhered to a solid floor, and nailed through the tongue on a wooden floor.

If they just slotted together it would all flap about in the middle like laminate flooring does, but worse.

martinxxxxxx · 3 Dec 2009

no the foggiest, is there a flooring sectiojn to this site, hold on I will go and look

it looks like gluieng is the norm

martinxxxxxx · 3 Dec 2009

JBPElectrics said:
Ah, I am too used to victorian terraces with no cavity between....DOH

Hang on you may be right. Am I sure there is a cavity? Will check.

PrenticeBoyofDerry · 3 Dec 2009

parke flooring will be laid using pva/acrylic adhesive.
It's preparation of fixing every floorboard down, (screw tightly) and a substrate that may be nailed with ringshanks or screwed.
So that could well be the prob.

flameport · 3 Dec 2009

Parquet floors are glued down, so are essentially permanent. Old ones were fixed with hot bitumen or tar.

martinxxxxxx · 3 Dec 2009

PrenticeBoyofDerry said:
parke flooring will be laid using pva/acrylic adhesive.
It's preparation of fixing every floorboard down, (screw tightly) and a substrate that may be nailed with ringshanks or screwed.
So that could well be the prob.

Yes I do know this I have it in the kitchen here. It is going to be difficult to get up isn't it?

Can't wait to find this fault now.

diynot

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One leg of ring main low ohms between all conductors

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