Earth Sparking

[piz]

Hello all
Just been called by my gas man when his vacum cleaner touches the copper pipe work it causes sparks
he said they are easy to see in daylight and asks if he will be safe to remove earthing clamps
I have no idea on sort of system yet or if an rcd
has anyone experinced this before and what do I need to look for to put it right
Cheers

 

[acat]

Sounds like you have a leakage to earth so I doubt its RCD protected. He cannot remove the clamps if it is a leakage to earth and those clamps are removed the leakage has nowhere to go, if someone touchs the fault it will probably be the last thing they ever do.

Switch of supply and do all tests as if its a new instal. Check out the hoover as that may be the actual fault.




Chris

 

[Des 56]

I would guess that the vaccum cleaner is building up a static charge and is being discharged via a earthy pipe and may not be a problem,however
Is the discharge occasional or consistant ?

Either way follow advise off acat for safety

 

[eskimo39]

Hi it sounds like a fault with the cleaner which is earthing through the pipes or if the brush is rubbing it could just be building up static, however I would check to see if there is any voltage in the pipes when you go around. I recently had a lady who kept getting an electric shock off her sink, when I checked there was just over 100v between the sink and neutral, after a bit of searching I found a live that had come loose in a socket and was touching the back box energising the earths but not tripping the mcb for some reason.

 

[piz]

Hi Guys
Thanks for the info I will post the outcome tonight can I test the hoover on a normal tester or do I nees a pat someone said do an IR test in it how and what voltage? as a domestic installer I have only ever used 500v DC on Dwellings
Cheers

 

[Eggster71]

If the hoover has exposed metalwork then test continuity to the earth on the plugtop.
Rated voltage of hoover will be 230, same as supply electrics therefore test at 500V. Phase to earth then neutral to earth ONLY.
You're looking for a good low reading continuity wise and obviously a high insulation result, beware of any neon indicators on the cleaner though, even though you won't be going live to neutral they can still play havoc!
While you're there do a continuity test between the pipework and a socket earth terminal (supply off) to try and confirm the pipes are bonded to earth and not just to each other. It happens.

 

[piz]

Tested Earth Electrode was 368ohms now 135.5ohms with a new earth rod
and no sparking now
but surley this wont stop the sparking cos must still be some earth leakage?
should I test every circuit one by one all sockets are on rcbos I know this dont mean anything cos fault might me on unprotected circuit

 

[acat]

Over 200 ohms may become unstable however I know a lot of people including the NICEIC state that it should be under 100 ohms so you are almost there. Have a look at 411.5.3 on page 50 it refers you to other parts but at least you will know what you are up against.



Chris