Gotta question for high liners

[bobbo]

You know when you are in a corridor and everything bites you. Do you guys have anything or any device that tells you that you need to add more grounds when the induction is really bad. Those times when everything you touch burns the crap out of you.

i saw a video where that had a device that constantly measured induction ?and how much was going to ground. Who makes that equipment? Not a voltage tester? But once you ground and what you have is still bites because the field from the other circuits is getting bigger, something that monitors the inductions while the circuit is grounded and will tell you when the induction is changing? Indicates you might have to do something to alleve the situation by adding grounds or getting a better source of ground. So many guys on this site from all over the world, what do you guys do?

[bren guzzi]

When I worked transmission in the uk. Our engineers ( national grid ) knew the max potential and we grounded with the appropriate amount of grounds ( that were a certain dimension appropriate to the situation) . Don't know how they new ( probably a mathematical / electrical theory ).

Heres an example... When we were removing jumpers from a 400 , ooo kva line ( four wires ) it took 148 grounds " earths plus all the X arms were bonded together with the top earth wire
they called it a " double dress earthing procedure. "
They reckoned ( and still do ) that this was required to produce an equipotential zone that was safe to work on with one circuit live and the other switched out .

[US & CA Tramp]

I agree with Bren. The best thing you can do is make sure everything you are standing on or working on is at the same potential. Look up "equal potential grounding". It has been around since the late fifties. Why more lineman and companies don't use it is a mystery.

[bluestreak]

When we worked live or next to live 345 to ease the pain we wore conductive rubbers or conductive gloves under our leathers and we felt hardly anything, it kept your body "drained " and lessened the discharge. We had one 345 line that had a insulated shield wire where the downleads were not tied to the shield wire except in the middle of a twenty span section that was deadended with a small insulator it was designed to cut down on line loss from the coil effect of bonded shield wires and downlead and buried counterpoise. Only had one line built like that and that construction lead to the last death in the Transmission Dept. twenty years ago.

[Rob]

to what Bren said. Depending on the size of the grounds you are using they will have a short circuit rating. Like a 4/0 ground is 44.4 kA. Then the engineers will apply a fault duty rating to the circuit you are working on and that should determine the size and number of grounds. Hope that helps.

[climbsomemore]

You know when you are in a corridor and everything bites you. Do you guys have anything or any device that tells you that you need to add more grounds when the induction is really bad. Those times when everything you touch burns the crap out of you.

i saw a video where that had a device that constantly measured induction ?and how much was going to ground. Who makes that equipment? Not a voltage tester? But once you ground and what you have is still bites because the field from the other circuits is getting bigger, something that monitors the inductions while the circuit is grounded and will tell you when the induction is changing? Indicates you might have to do something to alleve the situation by adding grounds or getting a better source of ground. So many guys on this site from all over the world, what do you guys do?


The take away idea from and Grounding and EPZ training is those grounds do 3 things

Drain Capacitive current and inductive voltage from the wires and pole surfaces into the earth

Short the line an trip the fuses that feed the circuit

Heat up the worker and everything he can reach with the voltage that is causing the problem through Equal Potential Bonding installed on the Structure worked

Induction on a circuit is best dealt with by breaking the loop we created when "bracket grounding" was installed. In old style grounding ... when you couple multiple grounds through the earth... the grounded loop circulates the induction and the worker feels that in your example Remove the Ground connection and break the loop. That's the point of single point or "master" ground systems.

The more ground you connect to the earth-- the worse induction gets

[climbsomemore]

I agree with Bren. The best thing you can do is make sure everything you are standing on or working on is at the same potential. Look up "equal potential grounding". It has been around since the late fifties. Why more lineman and companies don't use it is a mystery.


After the safety guy explains it... your foreman decides it black science an the new lineman adds why the last job did it "different" we have 40 years of stupid.

They teach it at line schools and ape programs... it's not rocket science unless an idiot tries to dumb it down to his level.

[bluestreak]

I'm all for proper and adequate grounding but I think the original problem was the individual was acting like a capacitor and when he came into contact with a grounded piece of equipment he would discharge causing discomfort {and possibly incontinence} Unless you would bond yourself to the grounded part all the grounds in the world on one line wouldn't shield you from the induced voltage from a parallel energized line. When we were involved working on live energized parallel 345kv the induction was nasty we found wearing a conductive suit with gloves and boots created a Faraday cage of sorts and any discharge/pain went off the surface of the suit making the work tolerable.

[US & CA Tramp]

I'm all for proper and adequate grounding but I think the original problem was the individual was acting like a capacitor and when he came into contact with a grounded piece of equipment he would discharge causing discomfort {and possibly incontinence} Unless you would bond yourself to the grounded part all the grounds in the world on one line wouldn't shield you from the induced voltage from a parallel energized line. When we were involved working on live energized parallel 345kv the induction was nasty we found wearing a conductive suit with gloves and boots created a Faraday cage of sorts and any discharge/pain went off the surface of the suit making the work tolerable.

http://esci.net/IndustryPapers/ProtectiveGrounds1954.pdf

http://documents.mx/documents/grounding-techniques-that-save-lives.html


What I was taught has always been, Insulate, Isolate, Or ground using EPZ. If the EPZ is set up properly it works well because it energizes everything at the same voltage including the structure you are standing on. What you just described is the isolation/insulated method which works well to. what you described is a little of the bare hand method and then adding rubber gloves. Either way works just the management preference. I attached two links if your interested, BUT they are pretty dry reading. :eek:

[lewy]

I think you only have 2 choices, you either work it live or de-energized in a EPZ. The idea of working isolated without grounding is dangerous and has resulted in fatalities.

[rob8210]

I have said it many times , there are situations where grounding an isolated line creates an unnecessary hazard. This of course requires lineman that know how to work safely and are able to think about what they are doing.

[Orgnizdlbr]

I have said it many times , there are situations where grounding an isolated line creates an unnecessary hazard. This of course requires lineman that know how to work safely and are able to think about what they are doing.

I agree.......

[climbsomemore]

I agree.......


and the other 98% of the time we need to leave it hot or ground it out.

Some of the corridors we have in the US are hot enough from induction we need to "barehand" (bond on) - even on open line sections with conventional protective grounds in place