Shocking question!

[journeyman Mick]

About a week ago I got an electric shock in the shower :eek: . As I was turning the tap off I touched the metal button that holds the tap handle on. I got a boot that caused my arm to retract violently, so much so that the muscles are still a bit tender now. I carefully turned the tap off, only using the plastic part of the handle. I went out and checked the earth bond on the copper piping next to the HWS. I checked continuity between the copper pipes and the earth wire, the earth socket on an adjacent power point and the copper coated steel earth stake hammered into the ground outside. They were all only around the 3ohm mark.

I checked this because years ago I lived in an old farm house and we would get tingles from the shower taps. It turned out that the house system was earthed to the plumbing pipework, but unfortunately the gal pipes in the ground had long since rusted out and been replaced with PVC - so no earth. We fitted a new earth, no more tingles.

On the day when I got this shock there was a thunderstorm brewing, lots of thunder in the distance but no close lightening strikes. I'm wondering if this shock was caused by static build up from the thunderstorm, given that the house earthing seems to be okay. There's RCDs fitted to all the power circuits, but not the lighting or HWS circuits. Ideas anyone?

Mick

[gnu52]

Hello Mick,
This may not be relevant to your situation but I will make the comment in case it helps.
I have heard of similar problems when the earth stake is in extremely dry soil, even at depth, such as we currently have here, the solution being to wet the area to help improve contact. I guess this applies most to cracking reactive soils (clays).
It will be interesting to see what others come up with. Best of luck, Bill.

[Daddles]

Hello Mick,
This may not be relevant to your situation but I will make the comment in case it helps.
I have heard of similar problems when the earth stake is in extremely dry soil, even at depth, such as we currently have here, the solution being to wet the area to help improve contact. I guess this applies most to cracking reactive soils (clays).
It will be interesting to see what others come up with. Best of luck, Bill.

So Bill, you're suggesting he go have a leak on the earth pipe? :eek:

I'd be getting it checked. You can get shocks from electrical storms (as an aeromodeller I know that well enough), but I'd be checking the house before jumping to those confusions. A jolt large enough to leave your arm numb is too big to be comfortable with - what if it had hit a child?

Richard

[LineLefty]

Mick with the amount of investigation you've done, do you honestly expect anyone to give you more information? MAyhap it's time to call a sparky.

I had a similar experience in our siter in laws house. No one believed me when I said I was seeing flashed when my head touched the shower head. (only I was tall enough). Finally I realised that I was being earthed..................

[journeyman Mick]

Adam,
trouble is most sparkies seem not to know about this sort of stuff. I had a client whao was complaining about getting shocks when washing up, had asked all the local sparkies, no solutions. I ran an earth wire from the copper pipes at the sink out to a new earth stake - no more tingles.

Bill,
The soil is definitely not dry, it's the wet season here and we measure our annual rainfall in metres.

Richard,
the arm isn't numb from the shock, the muscles are a bit tender from the muscular contraction.

I was sort of hoping (still am) that the electrical gurus (engineers etc) that gave answers in the thread about running 110V, 60HZ tools over here would be able to help. I suspect that it was caused by the lightening activity because the earth connections are all sound and the fact that there's never beena tingle before (or since).

Mick

[PuppyPaw]

I have the same problem in my house when its storming/about to storm.
the first time it scared the crap out of me and I didn't end up with just a sore arm but **** too when I slipped (pulled the arm away, pushed into the wall which made me need to adjust my feet which landed safely on the conditioner that had been nocked over when my arm hit the wall of the shower with is a glass panel)

didn't happen again for over 6week or there abouts untill another storm.. Unfortunatly I am sometimes very slow on the uptake.. wasn't untill the third storm that I finally put two and two togther and relized that conditioner on the floor was bad when one is being shocked by taps

[Zed]

ok... qld has areas that do not have good earth conductivity. I dont know why perhaps this may alos explain your higher than average storage of emf converted to static electricity ..... I remember in the darling downs about 20 odd years ago when the first commander telephone systems came out there was a higher than average failure rate and they tracked it down to bad earth (literally).

I would firstly recommend that you remove the earth for your power from your plumbing and install a dedicated earth system. better to be safe than sorry old mate.

I dont know how serious your prob is but here is an extreme solution ;

install more earth rods (ie one on each cardinal point of your house) and really hammer the suckers in nice and deep - maybe even finding some iron rich earth to hammer it onto - try to keep the area wet (you may have to put some mulch on it to stop it drying up all the time, plant some shrubs that will help the water retention) , I would also lay some copper ribbon into your back yard in a radial pattern (like a river being fed by its tributaries in reverse where the river is the single point attached to the earth rod) making sure you use stainless steel nuts and bolts to do all the hook ups. thas what we used to do on all the telco and radio towers and it seemed to work. the copper ribbon need not be a thick gauge as the skin effect of high voltages will make the current travel near the surface of the copper anyway - this will make it cheaper to buy. you can do all this yourself too - you only have to bury the ribbon about 30cm to make it effective. dont use gal nuts and bolts or it will react with the copper.

You can get good earthing equipment from a place called "RF Industries" they supply good earthing stuff to the radio and telco industries, im pretty sure they would still have a sales office in brissy - (I used to be a comms rigger with them so I know thier stuff is good ) failing them an electrical supplier will have earthing rods and copper ribbon. make sure the earth stake is a stainless core with a copper sheath about 1.2m min length and plunge it in all the way baby (if you want you can put in an inspection pit over the rod so you can measure your ohmage. by the way the resistance will change accodring to the weather - hot dry weather will make your earth worse and increase the resistance

*** not a paid advertisement ****

[bitingmidge]

Mick...check out the earthing anyway.

I think Zeddie's pretty close to the mark though (but I'm not the black dot between an electricians buttocks).

There are areas of high ground discharge, used to live near one, but it was located over Moreton Bay, (near St Helena Island for those interested) and apparently receives one of the highest incidences of lightning "strike" in the state.

Twice I have been sailing through the area at night with thunder storms brewing, but a long way off, and had the same thing happen as your shower incident. St Elmo's fire to...a wondrous cobweb of light ripping up my arm to the shoulder....while the crew were standing forward on the trampoline oohing and ahhhing at the pretty lights. Took a few days for the arm to stop aching.

An electrical engineer of my acquaintance explained that lightning in fact travels upwards... so the high ground discharge areas are letting mini shocks go (in layman's terms).

If the other electrical stuff draws a blank, I'd be thinking about using a few lengths of plastic in the water lines to try to provide some insulation for the future. (Have done my whole house like that just in case).

P (lightning does strike twice on the same arm - be careful!!) :eek:

[Barry_White]

Mick

If I was you I would be contacting the local electical authority. These are the people that pull the sparkies up on any faults and will find things that a sparkie wont find.

[AlexS]

FWIW, RF Industries also sell some stuff (can't remember what it's called) that permeates the earth around earthing rods to improve the conductivity.

[Cliff Rogers]

.....(can't remember what it's called) that permeates the earth around earthing rods to improve the conductivity.....

stale beer????

[craigb]

located over Moreton Bay, (near St Helena Island for those interested)

Umm Midge, St Helena is in the middle of the Atlantic.
It's where thay banged up Napoleon. :eek:

Sorry, sorry, couldn't resist

Last year when I had the "shed" (which is actually under the house) wired, the sparky couldn't figure out why the new safety cutout kept tripping.

It turned out that the house wasn't actually earthed, even thought I could eyeball the earth wire connected to the cold water inlet :eek: :eek:

[bitingmidge]

stale beer????

It has to be strained first.

Preferably through the kidneys.

P

[Cliff Rogers]

Seriously though.... electricity is weird & lightning is even weirderer.

For something to bite you, you have to be at a different electrical potential to the thing that bites IE, you can touch one side of live 240 & it won't hurt one bit IF & ONLY IF you are not connected to anything else that completes the circuit back to the other side of the 240 generator. That connection can be via earth (taps, metal plumbing, bare feet on wet floor etc...) or through a faulty appliance or through a bare connection or directly to the black/blue wire if you are dumb/careless/unlucky enough to touch it.

SO.... if you are standing in a shower/wet bath tub/whatever & the tap bites you when you touch it, you must be at a different potential to the tap.
For that to happen, the wet floor or other plumbing you are in contact with must be at a different potential to the tap. This is a bit unusual 'cos if the HWS had an internal fault, it would be leaking away to earth via the copper pipes & the tap that bit you....so....

I reckon we go with the lightning theory on this one.

I've seen what happened to a bathtub in a lightning storm so I stay away from the bathroom during thunderstorms now.

In my Grandparents' house in the very early 60's long before they had 240V, they had a chip heater for making hotwater in their bathroom. It sat on a tiled floor at the end of the bath & had a metal chimney that went up through the roof.
During a thunderstorm there was a very close bolt of lightning & it was close enough to induce enough 'electrical' potential for a 'spark' (bolt) to jump from the brass tap on the chipheater to the enamal tub & it left a black mark all the way along the tub to the brass plug hole.

[vsquizz]

Mick, check that the telephone lighting arrestor earths are not common with the plumbing earth. If so just run em separate.

Also do a few voltage checks off the plumbing to be sure.

Cheers