our grounds... for you american types.

[bren guzzi]

Here's some pics of our grounds as promised.

The three copper rods are driven into the soil. Then attatch the ground to it.
Lift the earths onto the line. They push on , "spring loaded". Pic of where all three are joined aswell..

Happy now ?????

We are . This job cancelled for today. Heading to Perth deppo. Might be going away to do some gaults..... The snows hit... :)

[neil macgregor]

oh right thats what they ment by grounds lol

[lewy]

I understand that you do not have a neutral so you have to rely on a driven ground rod, but I am surprised that you are using live line clamps that are not designed for grounding, they can not handle the fault current, I am also surprised that you do not bond your grounds to the pole to create an equal potential zone. No difference of potential no current flow & it is the current that kills.

[bren guzzi]

These are only our "local" earths... The line is earthed by an earth switch at the substation. Its only an inter conector of about 60 span. All our lines are designed to trip at very low fault current. So these earths will triger that if required... We don't see a need to bond to the pole. How can a pole be of un equal potential ?????????

[rob8210]

Hey Bren, what Lewy is talking about is called equipotential grounding. Another term for is point of work grounding or working grounds. When we use this type of grounding we ground out the primary to the neutral and a pole bond and if out in a rural area we use a ground probe too. You see by bonding the pole we make a zone above us and below our feet that is guaranteed to be at the same potential in someone should screw up and energize the line. Yes it is only for an instant, but if you have this zone then there can be no difference in potential across you at all. So no chance of getting hurt. When you ground at both ends of your work zone, we call that bracket grounding. It has been proven to cause a circulating current , under the right circumstances. We also must be within 100m of a set of working grounds. Hydro One in Ontario has tested this extensively and point of work grounding is their preferred method. In their line trade handbook it states" bracket grounding does not protect the worker". We can still use bracket grounding in some situations but the area manager and the safety department has to approve it first. I went through this whole issue a couple of years ago while working with a local PUC. They have a slightly different rule book. We were re-insulting some 44kv line that crossed under a 500kv transmission line. One of the fellas on the job was on their safety committee, and he didn't understand why I bonded my pole to my grounds.

[bren guzzi]

Our poles don't have any bonding to ground... So how do ya make it an euipotential zone ????

[rob8210]

the poles do not need a pole ground use a bolt that is holding say the x-braces. run your ground from the temporary ground probe to the bolt in the pole then take a ground from the bolt on up to your phases. That will bond the pole to your working grounds and make a safe work zone that will always be at the same potential between your hands and your feet.

[rob8210]

Hey Bren I just googled equipotentail grounding. The first site I looked at was www.atcoelectric.com. It has a pretty good explanation.

[Bighorn Ape]

we use something called an EPZ Bar to attach to the pole beneath our feet... it is a chain that tightens around the pole with a grounding bar on one side.

[bren guzzi]

Sorry...... But it don't work like that... :(

The pole or steel work on it have NEVER had a current in them or would they be able to.
You can't get a different potetial unless they have the capacity to conduct electricity. If that was the case you would need to be able to get a differnt potetial from "a wodden pole" to the steelwork ..... And if that was possible..... Every pole would burn down every time it rained. :)

[rob8210]

Have you ever encountered stray voltage at the bottom of a pole? A leaking insulator will be the cause. Take a voltmeter from anywhere on the pole to a good ground and you will get different voltage readings all the way up the pole. I've seen where there was 240v about 2 feet up. The cause was a leaking 2400v insulator. The voltage on the pole got lower as we went further down the pole. Wood poles are conductive. Some kinds more than others. Its that difference in potentials that will seriously hurt or kill lineman. A grounded line can kill a man either from induction or accidental energization. That simple step of bonding the pole below your feet will save a mans life. To prove it make a minature pole line, use a light bulb in the middle connected up to a phase and a neutral to simulate a lineman working on the line. Place a ground at both ends of your line and hook it up to normal house voltage( 110v) over here. Then flick your switch, the light bulb will go on and back off as the fuse or breaker trips. Now place an additional wire at the base of the light bulb to the pole and try again and see what happens.

[Bighorn Ape]

when i was in line school they had a demonstration of epz vs. bracket grounding...with the light bulb etc....

there was still current flow in the bracket grounding, but none in the epz.....it still seems weird to me too.

[bren guzzi]

Too tired at the moment to explain.... I know how an equipotential zone works and why you need them......... But I'm just outta bed after a 19 hour day yesterday. Snow and wind and trees and pole lines DON'T MIX... :)

[lewy]

Too tired at the moment to explain.... I know how an equipotential zone works and why you need them......... But I'm just outta bed after a 19 hour day yesterday. Snow and wind and trees and pole lines DON'T MIX... :)

I am curious if you how it works, why don't you guys use it?

[bren guzzi]

I am curious if you how it works, why don't you guys use it?

Would you get a diference in potential if you were building a new line that wasn't near another line. ???????? ..... That wasn't conected to the rest of system anywhere and phisically couldn't be ? And even then you wernt making or breaking jumpers and you were only working on an inter pole ( binding in / tieing in ) .... NO YOU WOULDN'T.

Well that is the condition of the line we are working on . Although it was live . We have switched it out in such a way that it meets the condition of a line that never was live. We use the grounding at the work point mainly as a line identification confirmation.

[lewy]

Would you get a diference in potential if you were building a new line that wasn't near another line. ???????? ..... That wasn't conected to the rest of system anywhere and phisically couldn't be ? And even then you wernt making or breaking jumpers and you were only working on an inter pole ( binding in / tieing in ) .... NO YOU WOULDN'T.

Well that is the condition of the line we are working on . Although it was live . We have switched it out in such a way that it meets the condition of a line that never was live. We use the grounding at the work point mainly as a line identification confirmation.

Well for a line that has no chance of becoming energized, you go through a lot of trouble of installing 3 ground rods with live line clamps.

[BigClive]

Well for a line that has no chance of becoming energized, you go through a lot of trouble of installing 3 ground rods with live line clamps.

Just because you believe a line can't become energised doesn't mean it won't. All it takes is some random incident anywhere along it's length and suddenly there are dead people.

Better to make it a habit than die through complacency.

How many linemen have died over the past few years in the UK Bren? I don't think it's that many. The bulk of any deaths will be with the "facilities management" companies using cheap ill-trained labour to get their finger into another lucrative pie.

[bren guzzi]

Now yhat you ask... NONE have died in the uk or IRELAND in well over 5 years. It might be the fact that. Companys are awared contracts on their saftey record rather than "SPEED" and PRICE .

I havnt even menntioned the use of "key safes" on this forum yet. Might post that tonight if I get a chance.

[BigClive]

I haven't even mentioned the use of "key safes" on this forum yet. Might post that tonight if I get a chance.

Hey! I've got an angle grinder pal. It doesn't matter how many of your pretty coloured padlocks you put on your safe or lock-off clamp. I'll still get it open. :p

I've got one of those multi-padlock lock off's somewhere. I think it was given to satisfy a safety requirement or something.

[bren guzzi]

Hey! I've got an angle grinder pal. It doesn't matter how many of your pretty coloured padlocks you put on your safe or lock-off clamp. I'll still get it open. :p

I've got one of those multi-padlock lock off's somewhere. I think it was given to satisfy a safety requirement or something.

I'm gonna write about key safes now. An stick it up in a bit. "Even you would struggle CLIVE " ;)

[lewy]

Just because you believe a line can't become energised doesn't mean it won't. All it takes is some random incident anywhere along it's length and suddenly there are dead people.

Better to make it a habit than die through complacency.

How many linemen have died over the past few years in the UK Bren? I don't think it's that many. The bulk of any deaths will be with the "facilities management" companies using cheap ill-trained labour to get their finger into another lucrative pie.

Exactly & that is why equal potential grounding is the only grounding that will protect you if the line is accidently energized.

[paul maxwell]

hi guys,just to get my word in here to what lewwy was questioning if these clip on earths would work in an emergancy,trust me they do.me an the rest of my gang where on a fault (11kv +25mm copper) when the f*cker of an engineer got ordered to close an airbrake on another part of the line and as you can GUESS what happened next eh,he only went and closed the wrong 1 and the only way we new what had happened is when the line snapped two span from were we wher and the line hit the deck(these clip on earths did save my ass and another two of my guys)and this was a sse job bren

[bren guzzi]

Bet he wasn't sacked either. ?

That's what they are there for. :). Never had it happen to me in over 30 years. "TOUCH WOOD".

[rob8210]

I'm sure glad no one got hurt out of that incident. Did anybody have hands on the conductor at the time? I hope not. The point I am making is if you were hands on at that exact moment there would be a potential difference between your hands and your feet, possibly going across your heart then you would probably need your defibralator. That pole bond I keep mentioning would eliminate that potential difference. With the type of grounds you use you could easily add one more ground and attach it to a pole band just below your feet. I'm thinking it would help in the event of a lightning strike too.

[paul maxwell]

aye bren,the engeineer wasnt sacked(nearly got his lights p*nched out tho),turns out both airbrakes had simler names eg hill farm and hill house.after the investigation it all got brushed under the carpet(prob coz the board was at fault).im like you mate never had this happen in 19yrs of line work so it just gose to show that when faults come it pays to have an engineer of the old scool with you rather then some uni,training school prat that gets tyerd after 10 hours eh.still we live to climb again:)




every days an adventure in linework:)

[Bipeflier]

http://www.hubbellpowersystems.com/literature/encyclopedia-grounding/

Bren, you might want to look at this. Particularly section 7

[SOUTHWEST LINEY]

Coming from the same lands as Bren we dont bond our Circuit Main Earths /additional earths to the pole we're working on either. Unless there is an earth on it already thats when we would directly connect our earths to it! to keep everthing at the same potential
.

[lewy]

Coming from the same lands as Bren we dont bond our Circuit Main Earths /additional earths to the pole we're working on either. Unless there is an earth on it already thats when we would directly connect our earths to it! to keep everthing at the same potential
.
You should, you want the pole & hardware at the same potential as the conductors & in order to do that you have to bond the pole to any one of the conductors.

[SOUTHWEST LINEY]

yer mate i agree with what you guys are saying, gonna have a word with the boss and see what he says Monday!

[BillyMac]

Bren we use the same as you, clip on's and screw on's ( the laatter can be a pain in the ass). Ours all come to a common earth tail which we connect to a known earth or if none around a similar earth stake to your's driven in a min 600mm.

Seen Clip on's have been put on with tel-o-pole can be a tad weighty with all three on the end .