Sparking noise from water pipes whilst doing Ze test

egginyourface · Mar 31, 2011

Evening all,

today i was doing a fuse board upgrade. On completion i was testing ze and water pipes were sparking. On further investigation found no earth presesnt.

tested ze on non trip mode and got 500 ohms. Fitted an earth rod and managed to get it down to 6.38 ohms with a pfc of 39 amps.

what do i do from here. ive notified customer of hazard and energy supply company will be coming down to have a look.

are there any measures i need to take for extra protection? do i need to fit an rcd on the supply end?

Deleted member 26818 · Mar 31, 2011

If it's now TT, you should (if only temporarily) fit an RCD.
Unless of course, you are certain that the 6.38Ω is stable.

egginyourface · Mar 31, 2011

thanks for reply spin

the board is protecting the circuits with rcd? i told the customer to let me know what the supply company say and how long till they sort it out.

do i still need to put rcd protection on sub main?

Engineer54 · Mar 31, 2011

What do you mean, ...by, water pipes were ''Sparking''??

Is that 6.38 ohms , ...Ra or Zs??

Deleted member 26818 · Mar 31, 2011

Do your Zs values allow the use of an overcurrent protection device?
If the Zs are too high, then yes you would have to provide front end RCD protection.

egginyourface · Mar 31, 2011

ok, yes. they were all higher than maximum permisable zs.

sorry this is a silly question front end rcd protection is from consumer unit to circuits or from meter tails and after.

who ever was there before me had taken earth from water pipes. water pipe was then interupted by water meter. so original sparks had fitted 2 earth clips to link over meter. these clips were loose so i guess thats why it was sparking.

never seen anything like it.