Got a buzz from a water pipe......

[Ookysoft]

Hey!

Am renovating a house.... involved stripping out the plumbing and start from scratch.

Was cutting through a hot water pipe and rested my hand on the cold - got a buzz. Popped the multimeter on and discover 90v.

Have yet to identify the circuits in the fuse box but taking 1 fuse out drops the voltage to 52, a 2nd to nothing.

Would the few pipes pick up induced current - so far, I've seen cable running through the same notches as pipes, under the floor.

Popping 1 of those socket testers in a few sockets and all, so far, suggest no earth in place. Does that explain why, when pressing the yellow trip tester... it doesn't trip? The earth isn't earthing?

There's the real old unsheathed earth running through plaster down to the watermain. I see [not poked around too much yet ] a thin sheathed earth [6mm?] from the breaker to the fusebox and down through the wall where it's cut from an earthing stake, and some thicker sheathed earth [10mm?] also running from the fusebox downunder the floor - ever hopeful it's doing something but I guess not......

I will have to get a sparky in to check out the whole lot, but intrigued by the source of the 90v really!

Also intrigued by what could possibly have been running on the 2nd [10mm?] tails out of the trip. Regular tails from meter to trip to fusebox but these thinner ones are cut and bared live, neutral and unsheathed earth of about 8" length just hanging there.... must have connected to something!

Mind you.... this is the place where the 8.5kw leccy shower was wired into the side of a broken wall socket in the bathroom.... used 2 lengths of cable and a bare terminal block just under the lip of the tray....... So nothing is going to surprise me... probably cut the earth as the trip kept tripping!! Hah!

 

[Taylortwocities]

There is probably a fault somewhere and also a missing earth, or earth bonding. Stripping out the plumbing may have caused the loss of continuity. If there is an earth electrode outside maybe that is no longer functional.

You should get a spark to investigate, and update all of the earth bonding. If you are renovating he/she would be doing that as part of the change of fuseboard. I am assuming that is to be done?

Why don't you post a picture of the existing fusebaord and incoming supply arrangements - always the cause of some amusement.

 

[Ookysoft]

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• Ookysoft
• 7 Mar 2010
• 1

2nd Bathroom - socket on wall under window. Cable wired into the back through a broken side.

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• Ookysoft
• 7 Mar 2010
• 1

Conn block under shower

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• Ookysoft
• 7 Mar 2010
• 2

Cooker cable - split to feed the cooker, extractor and another power shower through wall.

Will take the other pics tomorrow......

 

[electronicsuk]

Looks like you have your work cut out there.

As for the fault, I'd also put money on lack of main earth. The unknown 10mm may be bonding to gas or water supply.

I would give serious consideration to making it your next job to call out an electrician to inspect the entire installation. It would be bad enough under normal circumstances, but when you're likely to be running lots of electric hand tools and the like during renovation work, you're certainly tempting fate.

 

[Ookysoft]

I'm going delving under boards tomorrow.... Stripping out the last of the water pipes [ all of it! ] & redundant cable [lots of it - they were powering all sorts inside and out] - remove extension cables wired into the back of wall sockets and then follow the cables from fusebox back to fusebox.... I want to know what's going on myself first. I'm hoping the original rings went in place properly - before the last occupant started messing with it!

 

[1john]

sadly, if the installation has been chopped about as much as it appears then it may be more cost effective to have the place rewired, although this may not be quite as expensive as it initially seems if you can find an electrician who is happy for you to do the donkey work, which you appear capable of.

 

[Ookysoft]

Yes, was thinking of that [total re-wire ], actually - it's not a hard place to do and he wants all the sockets sinking in the walls so I have to have boards up, skirtings off and...... . And yes, quite capable of doing the work - never take on something unless I'm confident. Have me Part P defined [ which is really a waste of time and actually quite dangerous considering where I acquired it ], but more importantly, some common sense and a 17th edition to consult.

 

[Ookysoft]

A few more as promised...

The cut wires on the non-tripping trip - wondering what they connected to.

With 3 or 4 sockets on surface mounted extensions - originates plugged into a socket in the same room.

Yet, with all this spaghetti, why all the extensions? Heh!

Ah well...... step by step!

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• Ookysoft
• 9 Mar 2010
• 2

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• Ookysoft
• 9 Mar 2010
• 1

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• Ookysoft
• 9 Mar 2010
• 1

 

[Taylortwocities]

One of your problems will be that brown voltage ELCB.
It is redundant and obsolete
They don't work in todays installations, thats why it probably doesnt trip!

That will mean you need to protect the Wylex board on the left and sort out the earth cabling. Test them and bring them up to date. Put them together in a new MET with 16mm to each fuseboard.

That Crabtree board on the right. Is that a 30mA RCD being used as the incomer?

Tisk tisk.

 

[Ookysoft]

Hmmmm! The meter can't be that old - you'd think the leccy board would have condemned it if obsolete - then again, if the guy was to just put a meter in....

I'm going to say 'yes' but have no clue what MET is - will look it up!

The board on the right is for economy 7 - Storage heaters - these are going & I'll remove all that wiring. Have to have leccy in to swap meter about & remove the '7' tails.

Client wants that going in an outhouse..... will consult Building Control regards suitability.

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• Ookysoft
• 9 Mar 2010
• 1

 

[electronicsuk]

The meter isn't obsolete, just the ELCB.

 

[flameport]

Definite rewire time - nothing there worth keeping, and as the place is being refurbished, no better time to do it.

The third fuseway from the left on the white Wylex board has the wrong shield fitted - the painted edge types were from the older models which were dark brown.

 

[Ookysoft]

Sorry, I was referring to the ELCB - given the meter is recent, I was kinda assuming the out-of-date ness, would have been sorted when it [the meter] was put in.

Yeah, start from scratch -

 

[Taylortwocities]

I was kinda assuming the out-of-date ness, would have been sorted when it [the meter] was put in.
-

 

[1john]

DNO tend to only care that the meter is recording correctly and that you are making it clock up money for a big bill, they arn't fussed on the state of your wiring