Shocking question!

**Peter R** · 2nd February 2005, 05:42 PM

Originally Posted by TassieKiwi

Heya Mick

I think that before you go to any expense, get the performance of your earth checked. I'm a civil engineer and not schooled on the sparky side of things, but I did once have to check the quality of the earth of some building piles - for the lightning earth on a highrise. The technician had a windy-up gismo (like the old telephones) that created a charge and measured the resistance - quick and simple. I reckon if you talk to your electricity supplier, or a local Civil or electrical consultancy, someone would be able to do this.
Or, could be 'wet season drinking arm carpaltunnelitis', in which case, make a plastic foily and change arms.

Just dropped in to your post Mick, aint' ya glad???

The earthing would depend if you have Multiple Earth Neutral or Direct Earthing System in your area.

With Direct Earthing Systems earth Leakage Circuit Breakers are suppose to trip on an earth leakage, that is any current going to earth, where as the protection of MEN is just that, It is supposed to have many earth connections to disapate current in the neutral or earth system.

An acceptable, and usual earth resistance whould be around 5 to 10 OHMS. In most areas of MEN 10 ohms is accepted on the high voltage side of substations and 5 oms on the low voltage side. That is not to say that it is actually that as things change.

Sand is not a good earth, it is too porus, dense clay is the better earth. Some epsom salt around your earth rod will assist in the earth binding.

However, In the nonosecond that it takes lightning of millions of millions of volts and little current to strike, again supposedly the speed of light, you are cooked no matter what system your earthing system is.

Lightning is like firing a 17mm projectile out of a 357 magnum cartridge only more so.

When I was doing my electrical course way back in 62, I saw photos of cadavas that had been struck by lightning, why they showed us those photos I will never know, because if your number is up no memory of a photo will be of any use to you.

One photo showed a bloke, all his clothes burnt off and big holes in his body where his watch was, where he had change in his fob pocket and now this is the painful bit, where his ring used to be.

Another photo showed two dead people who were sitting in a line from one power point to another power point. The lightning came out of one power point crossed the room, did a hit on the oldies and made its escape via the other power point.

So what am I trying to say, I hear you ask....Well apart from not holding a metal rod in the air during storms, or standing under a tree, or sitting on the roof, if lightning is out to get you it will. But the good bit is that more than 60% of people hit by lightning survive, they are brain dead but....No just joking.

Peter R.

**scooter** · 2nd February 2005, 10:05 PM

Hang on, I think Eastie and WB are on to something.....

Er, Mick, did you happen to have an (ahem) electrical appliance in the shower with you??

:eek:

What about a Juicy Lucy inflatable friend?

These things can make your knees tremble.....er, so I've heard...

C'mon mate, spill the beans, you've kept us idiots in suspense long enough !

Cheers..............Sean, who showers to wash

**journeyman Mick** · 2nd February 2005, 10:42 PM

Thanks for all the help everyone!

In no particular order:
No, not using a hairdryer, because:
a)my hair's really short and in this heat dries in about 5 minutes anyway
b)common sense may not be very common, but I've got a smattering of it.

c) My name's Billy Hunt, not Silly C*** :eek:

I was standing in a showerbase awash with water, pretty good earth I would've thought.

That wind up gizmo is an old fashioned Meggameter (sp) You've just reminded me! I had a mate in Sydney years ago who was an apprentice sparky. There was a bloke on the jobsite who every morning without fail, would clock on and then go and read the paper on the dunny for half an hour or so. My mate and his boss got in early one morning and pulled the (wooden) seat off the dunny. They drove a series of fine pins through the seat from underneath thill they were just through the top. Looped a copper wire around to join them all up and ran a wire out the back of the dunny. Waited for the bloke to get in, sit down and get comfortable, waited about 5 minutes, wound the megger right up and pressed the plunger. Apparently the bloke hit the roof screaming and came out with his pants around his ankles :eek:

:eek:

I was going to say that I can't tell the difference between AC and DC when it bites (I try to avoid being bitten, usually successful), but I think I can. I got a really good whack from an electric fence unit which I assume is DC. Was using a metal knapsack sprayer and had accidentally turned it on rather than off. Touched it with the wand and next thing I know it's like a huge belt that threw me back a few metres to land on my back on the (now badly dented) knapsack. The other big belt I've had was when I pulled a porcelain fuse and discovered that some idiot had left a bit of wire poking out the top. I reckon they heard me bellowing in the next suburb. :eek: Not so much tingling as shaking. But not a straight whack like the fence unit.

I don't think I have Carpal tunnel syndrome, but how do you know? I do have tenosynovitis in both my forearms, and buggered tendons in my right shoulder and just recently trigger finger in my right hand, so more things breaking down/wearing out is entirely possible.

I don't own any "adult toys" besides all the gear in the shed. Got half an acre to mow, sheds to build, all the gear in the shed, stacks of timber (literally), an ex ballerina for a wife.

, and more projects than you can poke a stick at to keep me busy.

I'm off now to check out those links (thanks Simon) and will probably avoid showering during thunderstorms.

Thanks all,
Mick

**vsquizz** · 2nd February 2005, 10:50 PM

That wind up gizmo is an old fashioned Meggameter

Mick, living in a messdeck with 35 engineers and a dozen of the high power guys you see some funny things. None of the sparkys ever had a real reputation for jumping out of the fart sack at the drop of the hat. One of them was a real shocker, always took about 4 shakes to get him up and always late. One morning two of the off going watchkeepers arrived down the messdeck with the big megger. Connected the leads to the guys toes and gave it a good crank.

He became quiet adept at getting on watch on time after that.

BTW, did you find your lightning arrestors fo4r the phone?.

Cheers

**journeyman Mick** · 2nd February 2005, 10:56 PM

Squizzy,
I haven't climbed up in the ceiling to look yet, it's been too hot! I don't even feel like dragging the ladder up from the shed in this heat, I can't imagine that I used to build houses in this type of heat! (insert profusely sweating smilie)

Mick

**Buddabang** · 7th June 2005, 08:49 PM

Sounds like a bad or broken neutral. you shouldnt be getting any volts on your earthimg system. I'd get the distribution company to send out a fault crew.
If it is a neutral problem, your earth acts as a return path for the current so any metal fittings that are hooked up to the earth will have a difference in potential.
The more items you have switched on in the house, the more fault current on the earth system, the bigger the shock.

You shouldnt have more than one ohm on your neutral.

**knucklehead** · 7th June 2005, 09:49 PM

Mick, I have had more than my far share of these type of shocks from working in peoples houses. This is normally what I suggest to find the problem.
1. The power company will treat the loss of an earth seriously. If you call them and say the right words (i.e. I think the earth is not connected) they will come out and check. They will only check to the power box but thats a start. (did this on one job cause the earth rod was HOT, ended up this guys earth stake was the only working one for about 8 houses)
2. In most metro areas the neutral and earth are bonded. If this is the way it is your area its worth checking.
3. Could be a single appliance leaking. Most of the time its the defrost heater in the fridge (a classic sign of this is a frdge that sweats or has rusty external surface). Get each device "mega" tested. This checks for insulation between conductors.
4. RCDs and ELCBs are different. RCD will trip if the curent going to and comming from a device is not balanced. ELCBs will trip when they see current on the earth. Also they are often left off circuits that are problematic, easier than fixing the issue. Sad but true...

Yet another unqualified waffle to add to the list

**cookyboy** · 9th June 2005, 07:00 PM

greetings Mick.

WE had same problem, ccalled power co. it turned out it was the old wires where the power line meets the house .they came out immediatly ,did all the things you did ,then they pointed out to me the swolen insulation between junction box and power line. They were very good call them . its thier problem . no charges $ were made
Gordo.

**journeyman Mick** · 9th June 2005, 10:13 PM

Buddabang, Knucklehead and Gordo,
haven't had any problems since this single occurence. Had the connections and earth checked, I reckon it was the lightning strike.

Mick

**Groggy** · 9th June 2005, 10:25 PM

Originally Posted by journeyman Mick

Buddabang, Knucklehead and Gordo,
haven't had any problems since this single occurence. Had the connections and earth checked, I reckon it was the lightning strike.

Mick

Mick, nothing to do with you original topic, but I'll add something I heard today. An electrician was working on a house and turned off the power. As he worked he got a heck of a kick from the powerpoint he was working on. Apparently, TV's that are turned off with a remote are not really "off", and can contain quite a charge. He is now careful to turn off the TVs fully, before turning off the power.

**journeyman Mick** · 9th June 2005, 11:30 PM

Groggy,
years ago I got a boot from a tape deck, I touched the pins of the power lead which had just been unplugged. I deduced that I must have got a boot from a power supply capacitor, probably what happened to the sparky. On a similar note, it's possible apparently to get a boot from a tv aerial, something to do with stray high voltages in the TV. Apparently on a large multi tv/single aerial set up like on an apartment block, this can be lethal.

Mick

**Ashore** · 10th June 2005, 01:34 AM

Originally Posted by journeyman Mick

Buddabang, Knucklehead and Gordo,
haven't had any problems since this single occurence. Had the connections and earth checked, I reckon it was the lightning strike.

Mick

If you have had neutral connection at the point of connection to your house and the earth connection checked then all is well Just watch out for lightning.
In Newcastle N.S.W. You no longer need to have a dedicated earth the local authority allows connection to a copper water pipe they seem to think this is enough

The trouble with life is there's no background music.

**journeyman Mick** · 5th May 2007, 11:22 PM

I know it's a pretty old thread, but I thought I'd update it. The power company is moving the supply lines as currently there's a string of poles running down the middle of people's back yards and they can no longer access some of the poles. Some of these poles have been badly termite attacked. A fortnight ago contractors came out and knocked down a number of trees out on the roadside. Bloodwoods and red stringys. Guess who managed to snaffle all the logs?

Yesterday there was an air operated percussive track drill busy for about ten hours boring holes across the road. Wanderred over there late in the afternoon to find out what was happening. The bloke was installing earth cables for the new pole mounted transformer which is coming next week. Turns out this whole area has really poor earth and the bloke used up all the materials that he had onboard to install about a dozen or more earths and it was barely within specs. He reckons that my system's earth will be better as a result (but I'm still going to stay out of the shower during thunder storms).

Mick

**Pat** · 6th May 2007, 02:18 AM

Mick, what happened to the poles that were not termite ridden? Did you manage to "obtain" them too?

**journeyman Mick** · 6th May 2007, 04:22 PM

Originally Posted by Pat

Mick, what happened to the poles that were not termite ridden? Did you manage to "obtain" them too?

Pat,
not really interested in building anything with ex-power poles or milling them up. The power company is going to give one of the better second hand poles to our fire brigade. They'll be sticking it in the ground next to our shed so we can mount our radio aerials on it.

Mick

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