EPZ grounding

[thesilverfox]

I have had some questions pop up that I am having a hard time finding the answer. the question is, should the lineman installing the EPZ grounds install the pole band and then climb over the pole band before connecting the ground from the neutral to the phase and so on or is it ok to install the pole band and then the ground from the neutral to the phase and so on and then climb over the pole band to get in the EPZ zone? This seems to be utility/contractor specific. I have done a little research in OSHA but they do not address this specific question. I would appreciate any help on this I can get.

[jmorehouse24]

You should install the pole band, climb above it, then do your grounding. If you were to install your pole band, then ground, then climb over it; in theory you are going in and out of the EPZ. I don't necessarily know if I would call it a differnce of potential, but somewhere along the lines. I would have to say that either way would be safe, but grounding from above the pole band would be the more acceptable practice.

[lewy]

I think part of it would depend on how low your neutral is we put it a 10' on new construction. Either way after you have bonded your band to the neutral you would be in a comfortable position to install your grounds so whether you are above or below is not a big deal your feet will likely be close to the neutral either way.

[Daddyof2]

We always stood above the bracket to ground. Went to work for FPL and they said to wear rubber gloves to climb over it. When asked them how that helped with one foot over the band and one foot under it, they just looked at me and again said to wear rubber gloves.:confused:

[Fiberglass Cowboy]

You don't have to be above the bracket to connect the pole BRACKET to the main line NEUTRAL, if the neutral is lower than the phases. You DO however, have to climb ABOVE the bracket before going from the neutral to the PHASE(S), otherwise you are not in the equi-potential zone. Even if you have a high (static position) neutral, or no neutral at all (delta system, ungrounded wye or uniground systems) you are supposed to bond the pole ground to the grounding bracket (also a long ground jumper down to a driven ground) then climb above the grounding bracket before connecting the bracket to the phase(s). All to stay "within" the EPZ. We have 5 or 6 pages along with illustrations dedicated to this in our company's safety manual. :rolleyes:

[Trbl639]

You don't have to be above the bracket to connect the pole BRACKET to the main line NEUTRAL, if the neutral is lower than the phases. You DO however, have to climb ABOVE the bracket before going from the neutral to the PHASE(S), otherwise you are not in the equi-potential zone. Even if you have a high (static position) neutral, or no neutral at all (delta system, ungrounded wye or uniground systems) you are supposed to bond the pole ground to the grounding bracket (also a long ground jumper down to a driven ground) then climb above the grounding bracket before connecting the bracket to the phase(s). All to stay "within" the EPZ. We have 5 or 6 pages along with illustrations dedicated to this in our company's safety manual. :rolleyes:

That's the way we were taught.............if the neutral is below the phases...........hang the bracket, ground it to the pole ground, then jumper to the neutral, climb above the bracket and then ground the phases.....

[bones]

I'd hang the pole strap as far away as my shotgun is capable of reaching or at the length limits of my grounds. For instance, if I had a 4ft and 8ft ground and a 6ft line to neutral clearance, I'd rap the strap around the pole right below the neutral, and hand tie the 4ft ground from strap to the existing neutral (we don't run spools around here). With the 8ft ground, I'd then hand tie it to the pole strap and use my shotgun to go to the phase. Why?

When initially grounding, accidental contact is not the primary concern. Proximity to a very potential explosion resulting from direct phase to ground contact is! Being in an EPZ may save you from shock but not from 2000 degree heat lighting up three feet from your face...exactly where your face would be if you were above the pole strap. Not only that, how do you work a shotgun from that height...I mean why even use it, you're already there:rolleyes:

Jr. Engineer bird-dog got smart with me and proposed my apprentice climb above the strap, then use his shotgun to "reach out" on the line and tack it on there. Putting aside the endeavor of trying to get 20lbs of grounds hanging off a 8-9ft shotgun "up and out" eight feet, it took five minutes just to explain that the shotgun has to be perpendicular to the line to "turn" the ground on!:rolleyes:

After finally grasping that concept, he came up with the idea of "touching" the line out that far then sliding the shotgun and ground in to be tightened. Again, putting aside the fact that my apprentice would very well probably have to climb down to release the stupid thing, I mentioned to him, but what if that line is hot?

"So what, he'll be at a safe distance!"

Not really:rolleyes: The heat will undoubtedly melt that wire in two causing an eight foot hot wire to swing back to my apprentice.

"Then ground it on the f*cking source side"

I HEAR F*CKING GENERATORS! It doesn't matter.


---------

All in all, if your hooks are the only non-insulated thing touching the pole, I say you're a bird on a wire and it doesn't really matter if you're below the strap while grounding. I can think of better scenarios but I feel safe with this and don't feel like carrying the extra grounding material weight.

I'd have both my 2/0 grounds attached to the strap though. That puts 2/0 copper between you and ground no matter how you look at it and not having a "weak spot" like 1/0 or 2str. aluminum in the works.

[Resto-master]

Think EPZ is the better choice for grounding however the only bad thing to my mind is if a Fault occurs, those ground chords whip around at like 1000mph possibly decapitating you, saw a video of it. So the danger still isnt fully out of the linework hence the pay.

[heelwinch]

I have had some questions pop up that I am having a hard time finding the answer. the question is, should the lineman installing the EPZ grounds install the pole band and then climb over the pole band before connecting the ground from the neutral to the phase and so on or is it ok to install the pole band and then the ground from the neutral to the phase and so on and then climb over the pole band to get in the EPZ zone? This seems to be utility/contractor specific. I have done a little research in OSHA but they do not address this specific question. I would appreciate any help on this I can get.


It's all in the name... Like the Cowboy said... If you're outside it when you attach primary, your out of the zone.

No Offense but questions like this make me wonder how some hands make it to retirement. This is basic theory that any half assed lineman should be aware of at all times, even if they spend most there days on the ground or a digger.

[Edge]

You don't have to be above the bracket to connect the pole BRACKET to the main line NEUTRAL, if the neutral is lower than the phases. You DO however, have to climb ABOVE the bracket before going from the neutral to the PHASE(S), otherwise you are not in the equi-potential zone. Even if you have a high (static position) neutral, or no neutral at all (delta system, ungrounded wye or uniground systems) you are supposed to bond the pole ground to the grounding bracket (also a long ground jumper down to a driven ground) then climb above the grounding bracket before connecting the bracket to the phase(s). All to stay "within" the EPZ. We have 5 or 6 pages along with illustrations dedicated to this in our company's safety manual. :rolleyes:

'nuff said...

[US & CA Tramp]

I have had some questions pop up that I am having a hard time finding the answer. the question is, should the lineman installing the EPZ grounds install the pole band and then climb over the pole band before connecting the ground from the neutral to the phase and so on or is it ok to install the pole band and then the ground from the neutral to the phase and so on and then climb over the pole band to get in the EPZ zone? This seems to be utility/contractor specific. I have done a little research in OSHA but they do not address this specific question. I would appreciate any help on this I can get.

In approximately 2001 OSHA's only D,T,&G Specialist made a video/CD on the very subject of EPZ, and addressed this subject in it. He also went to different parts of the country and taught courses including the installation of an EPZ. You should be able to get copies of this from OSHA. Equal Potential Zone way of grounding is not new, It was first developed and used by Bonneville Power Authority in the 1950's.

[thesilverfox]

It's all in the name... Like the Cowboy said... If you're outside it when you attach primary, your out of the zone.

No Offense but questions like this make me wonder how some hands make it to retirement. This is basic theory that any half assed lineman should be aware of at all times, even if they spend most there days on the ground or a digger.

In response to your post Mr. heelwinch I have found that a lot of linework is performed a little different on the east side of the states than in the west. I asked a viable question as I have heard two schools of thought on this. For one the resistance on the ground cable is lower than the human body and basic electrical theory tells us that electricity will follow the path of least resistance, so the climbing over the pole band would be acceptable, two, when the EPZ grounding came out the idea was to create a zone as small as possible while working on the grounded phases to reduce any step and touch potential, hence climb over the pole band after the conductors have been grounded. To my knowledge most of the utilities and contractors on the west side install the band, ground the phases, climb over and go to work. Which I am sure that you already knew all this being the expert on basic theory and am an apparent expert in all aspects of linework. No offense.:rolleyes:

[thesilverfox]

In approximately 2001 OSHA's only D,T,&G Specialist made a video/CD on the very subject of EPZ, and addressed this subject in it. He also went to different parts of the country and taught courses including the installation of an EPZ. You should be able to get copies of this from OSHA. Equal Potential Zone way of grounding is not new, It was first developed and used by Bonneville Power Authority in the 1950's.

Thank you very much that bit of information! I have done some research in OSHA however I was not able to come up with that, I will do some more checking, again Thanks.

[bones]

It is a good question, no doubt:)

What also must be understood is that a person is not in an EPZ until that ground is actually attached. Simply climbing above the strap first thing doesn't put anyone in any particular "zone"...maybe a danger zone of violating various approach distances. That's assuming we're still considering everything hot.

But hey, if someone wants to work their way up and over a twisted nest of potentially hot secondaries, over a hot can, and thread their belt through the cutout stinger all in the sake of putting on a ground, go ahead. Kind of sounds like cutting your nose off despite your face to me though.

[MI-Lineman]

In response to your post Mr. heelwinch I have found that a lot of linework is performed a little different on the east side of the states than in the west. I asked a viable question as I have heard two schools of thought on this. For one the resistance on the ground cable is lower than the human body and basic electrical theory tells us that electricity will follow the path of least resistance, so the climbing over the pole band would be acceptable, two, when the EPZ grounding came out the idea was to create a zone as small as possible while working on the grounded phases to reduce any step and touch potential, hence climb over the pole band after the conductors have been grounded. To my knowledge most of the utilities and contractors on the west side install the band, ground the phases, climb over and go to work. Which I am sure that you already knew all this being the expert on basic theory and am an apparent expert in all aspects of linework. No offense.:rolleyes:

Uh? We don't do much (if at all) EPZ grounding cause we tend to glove (only 5K and below mind you!) or work it hot or as if it was but I believe EPZ also came about due to the fact "electricity follows ALL paths to ground" NOT JUST THE PATH OF LEAST RESISTANCE? So whether we or the ground have the lower resistance you're still a path!

I guess I wouldn't take that chance?;)

Kind of a catch 22 whether you want the smaller area for step potential and climb over after or a larger area to ground in to begin with?

Me the later of the two?

[Fiberglass Cowboy]

Bones...

... Very good point with your first response about not wanting to be around (near) any phases while connecting from pole banding bracket to phases. I could definitely see not wanting to climb above bracket on poles where the neutral is crowded to phases; like within 4'-5' ft. of phases. We generally use digital (high) voltage indicators made by HD, to test phases for any potential before grounding. There is an audible and visual warning. They sound off by beeping loudly and give and approximate digital (large bright red numbers) readout within 100 volts if there is anything on the line. They are good from 100 volts to 99kv. They run off of a 9 volt battery. However, some trucks still only have the ol' "potato masher", orange Salisbury high voltage indicator, with adjustable settings. We are now looking at going with the new Hastings digital (high) voltage indicators which cover an even wider range. It is policy for us to test before grounding, as I imagine it is at most bigger companies. I'm pretty sure a guy would still be safe below the bracket if he had just tested the phases before grounding, unless the line "magically" became energized in those few seconds between testing and grounding. This is not very likely. "Magically" I could be struck by lighting or die in a car accident tomorrow, but we don't tend to worry about those kinds of things. Definitely see your point though, 'bout not wanting to be right there on top of everything, but down and the hell out of the way. Makes sense. I suppose if I couldn't temporarily lower (for various reasons) a close'n'crowded neutral wire before bonding it to the pole grounding bracket, I wouldn't want to be above it right up on the phases either. Put in a dozen different situations, the same lineman might choose to ground a dozen different ways, and they might all be just as safe and in accordance with their companies policy. It's too bad though, that most of us get to have little or no input on our companies safety manual and our safety rules. So to each their own, as long as we're working safe. I believe that most situations from day to day - amongst different linemen, different line crews, different electric companies and different parts of the country are going to be different from one and other; unique, - even if only by a little bit. ;)

Stay safe out there brothers ..... no matter where you are. :cool:

[LINCRW]

Can you ever create an EPZ? If you think about it, the farther you get away from the pole band, you will still be in a zone of un-equal potential with every step you take; regardless of whether you are above or below the band. The EP zone is a good theory, but in practical applications, when you think about it, can you ever create EPZ? I'm not knocking it, but questioning whether it can ever be obtained in practical applications.

Don't get stuck on accepting only one type of grounding as being the safest. Some grounding methods work better than others depending upon what you are grounding, and how you choose to do your work.

[west coast hand]

It's a little different out here alot of delta and if it is wye the neut is on the same arm as the phases we don't put it 6 ft down like the do back east we will drive a ground rod and run a ground up the pole to the band and climb over it we hardly ever ground most of the time we work it hot because you can't usually get an outage on main feeders and what's even more screwed up is the UG epz grounding but that a whole nother topic

[CPOPE]

I have had some questions pop up that I am having a hard time finding the answer. the question is, should the lineman installing the EPZ grounds install the pole band and then climb over the pole band before connecting the ground from the neutral to the phase and so on or is it ok to install the pole band and then the ground from the neutral to the phase and so on and then climb over the pole band to get in the EPZ zone? This seems to be utility/contractor specific. I have done a little research in OSHA but they do not address this specific question. I would appreciate any help on this I can get.

I've got the same question from time to time and can tell you people will argue which way is correct till they are pissed off or pissed drunk. LOL Don't really matter, Explain to the person questioning the whole concept of "Equal Potential" is keeping your hands and feet at the same potential. There are three main electric hazards, Step Potential, Touch Potential Arc Flash Arc Blast, Shit no that's 4 hazards not 3 and I forgot about that ****&squeeze makes it 5. Keep your hands and feet at the same potential by keeping your rubber gloves on once it is grounded even though you need not keep your gloves on when ans once it is grounded keep them on if you're working on my truck, it's extra protection to keep gloves and sleeves on why take them off?. Hang the pole band below the neutral at the top communication conductor and bond it to the frame of the truck even though you don't really need to. Everything is bonded together with a 2/0 ground than if there is a fault the maximum potential you can get across your hands and feet is the voltage drop across the 2/0 caring fault current. Shit you got a pole band on the truck use it even if you are doing bucket work, I saw a guy put up a pole band for his hand line and bond his truck every pole he worked. This same guy would drive a ground would bond all the communication to the system neutral whether or not the WO called for it., Just the way he did things. Mean bastard worked like a dog ever-day while I slacked. Some Utilities I've worked install a grounding but plate and down ground on every pole some only ground the minimum requirement of only 4x per mile, Utility specific practices. In general the more the better. Some utilities require you bond the truck to the system neutral if available, that sucks! but it's safer. I know several guy's who have gotten belted toughing the truck w/o gloves. Not really needed but it is once you see a feed bag for tools and a hand line hanging off a pole band bonded to the truck you'll do the same. Just a good work practice and looks pretty, Beats hanking it off a xarm where it gets in the way.

[lewy]

Cope are you saying that where you work the men have to wear there rubber gloves when working on a line that is using EPZ grounding?

[Pootnaigle]

Grounding can be done sooooooooooo many ways that it takes a philadelphia lawyer to settle on one. Today several old friends of mine were sent home for an undisclosed amount of time because they didnt adhere to some purty stringent rules when grounding. In fact they may not have even had a clearance. In this particular instance I bleve the saftey rules would have required sumpin like 9 sets of grounds installed at various locations.I know that get er done attitude perpetrated this incident( which didnt get enyone hurt) Just had the wrong guy see it type of thing. I hate what happened to em but in all truth They were wrong for doin it...... Just sad to see 20 and 30 year people indefinately suspended for an infraction such as that. I understand one of em is fired and perhaps all 3.My advice is to do the get er done part after ya do the proper grounding.This was a clear cut case of following the rules but tripeling the length of the outage. or cut a corner and get the wire back up in the air................. Looks like they may have cut a career ending corner.

[Trbl639]

Grounding can be done sooooooooooo many ways that it takes a philadelphia lawyer to settle on one. Today several old friends of mine were sent home for an undisclosed amount of time because they didnt adhere to some purty stringent rules when grounding. In fact they may not have even had a clearance. In this particular instance I bleve the saftey rules would have required sumpin like 9 sets of grounds installed at various locations.I know that get er done attitude perpetrated this incident( which didnt get enyone hurt) Just had the wrong guy see it type of thing. I hate what happened to em but in all truth They were wrong for doin it...... Just sad to see 20 and 30 year people indefinately suspended for an infraction such as that. I understand one of em is fired and perhaps all 3.My advice is to do the get er done part after ya do the proper grounding.This was a clear cut case of following the rules but tripeling the length of the outage. or cut a corner and get the wire back up in the air................. Looks like they may have cut a career ending corner.

Entergy hands Poot?

[Pootnaigle]

Sho nuff.......... 2 foremen and a lineman outta Beaumont.As I understand it they were all sent home indefinately until an investigation is held. I think thier intention was to work it as hot passing the downed conductor up to a lineman in the bucket with a shotgun and he resagged it and sleeved it( probably without the benefit of a jumper first) the layed off lineman was told to install a preform around a damaged conductor and he did that without the benefit of rubber gloves or cover of any kind. In this particular instance I think sumpin like 9 sets of grounds would have to be installed ( one set at every potential source ( open switches used for feeder ties, and of course at the sub station where the 2 feeders originated) They would also have to be removed after the work was completed before restoring power to the numerous customers in a very affluent area. Im purdy sure the consencious of opinion was they could do it in a fraction of the time, if they didnt take a clearance and worked it as hot.Unfortunately they maybe skipped a few steps on the working it hot part.

[CPOPE]

Why in the hell would you ever in the flippin world have to hang 9 sets of grounds. unnecessary so say the least. All I need is a single point ground and bracket grounds. The circuit cant go in 9 different directions from a single work area, hang a ground on either side of UR location and go to work

The pros and cons of single-point equipotential grounding, as opposed to working between your grounds or bracket grounding, has generated a lot of discussion. As found in IEEE-1048 Guide for Protective Grounding of Power Lines, single-point equipotential grounding is becoming more simply and accurately referred to as worksite grounding. In most cases, those who don't trust worksite grounding don't understand how or why it works. In fact, we have always been taught as linemen to "work between your grounds," and that seemed like good advice. But it may not have been the best advice.*

THREE IMPORTANT FUNDAMENTALS
In order to accept the theoretical logic of why equipotential worksite grounding works, you need to remember three basic fundamentals from basic electricity.
First fundamental: Most not all electricity (voltage and current) always flows through the path of least resistance.
Second fundamental: Electricity will only flow where there is a path and that path always returns to the source.
Third fundamental: When there is a parallel path, there is always flow through both paths and the greater flow will be in the path of least resistance.
You also need to understand that the human body can, and often does, withstand small or unobjectionable current flows across the body and that the body has significant resistance (reported to be about 1000 ohms) that can resist current flow.

UNDERSTANDING INDUCED CURRENTS
While grounding protects against unintentional energizing of cleared circuits, there should be just as much concern placed on induced voltage (capacitive) or current (inductive) on de-energized lines. Induced voltages are caused by energized parallel circuits or where energized circuits cross other circuits. The hazard of induced voltage is even more important with today's higher distribution voltages and the addition of more transmission circuits to serve expanding loads. Induced current is also known as magnetic induction. Magnetic induction is different than induced voltage in several ways.
• Induced voltage is dependant on the distance of air space between the source circuit and the line on which induced voltage is present, just like induced current.
• Induced voltage, however, is not dependant on the parallel length of the two circuits where induced current is very dependant on the length of the parallel lines.
• Induced voltage is dependant on the level of the voltage in the source circuit

CIRCULATING INDUCED CURRENT
WORKSITE GROUNDING CONNECTIONS
With magnetic or electrical induction, a worksite ground still has current flow, but all of the conductive components bonded together are at the same potential, minimizing the risk of injury. The first connection is to install a grounding bail or grounding cluster bar securely and directly to the pole below the system neutral. The bail provides a common connection point for all the ground connections and makes an electrical bonding connection between the wood pole and grounds. The next connection is from the bail to the system neutral. Use conductor lengths as short as is possible when making connections in the grounding scheme. The third connection is from the bail to the phase and, of course, phase to phases.
As usual it is imperative for the integrity of this protection scheme that all connections be virtually resistance free. This means approved grounding clamps, sufficient conductor size** (no less than #2 copper) and properly wire brushed conductor surfaces, as well as wire brushed ground clamp surfaces.
In this arrangement, an unplanned current, whether from fault or induction, will be passed to ground around the protected area between the limits of the phase and ground connections. A lineman on the pole, feet planted above the bail with hands on the phase, will be in parallel with the protection scheme. But, since induced voltages or currents constantly flow through the common connected scheme, there is no "potential" difference to create a hazard. If there is a sudden rise in voltage because of an unplanned energizing of the circuit, the voltage rises on all connected parts of the zone protecting the worker. A hazard still exists for workers on the ground. Around the pole or equipment connected to ground, there will still be high potential differences between each piece of grounded equipment AND the equipment and earth. There will also still be ground surface voltage gradients radiating out from the earth connections. Persons at ground level are not protected by worksite or bracket grounding and must take appropriate measures for personal protection from those hazards. (See image for further information on this topic.)

TOUCH POTENTIAL ABOVE THE NEUTRAL
A frequently asked question concerning worksite grounding is about touch potential on the wood pole between the lineman's feet and hands if he is touching the pole during a fault. For touch potential to exist there must be current flow and resistance across the touch surface to produce a difference in potential. From neutral to pole top, all of the components including the wood pole are bonded together so the voltage on all surfaces rises at the exact same instant. As a result, there is no voltage gradient to create a touch potential hazard.

BONDING WOOD POLES
OSHA requires that for the purpose of fault and protective ground calculations, a wood pole must be considered a conductor because the resistance of the pole changes from day to day depending on atmospheric conditions. Poles used to be routinely bonded from neutral to pole top pin. That is not always the case today for high BIL purposes. Pole top bonding helps to reduce the resistance of the pole, making it more conductive. Bonding of a wood pole to bring it to equal potential with all other conductive surfaces is one of the keys to effective worksite grounding. The pole bond plays an important role in the scheme and, if installed, should not be removed.

THE LAST CONSIDERATION
Any protective grounding arrangement jeopardizes the safety of persons on the ground. Grounding, whether bracket or worksite, is placed to protect the employee aloft. All of the above mentioned configurations expose the employee on the ground, k.
If a remote fault impresses current on to the neutral, any person touching that equipment is exposed to contact. In addition, since that current is impressed into the earth through the ground rods or the truck, the ground in the vicinity of the rods or truck will be electrified. Because the earth has varying degrees of conductivity, even over the course of a couple of feet, there exist differences in potential that can cause the electrocution of an individual who has been exposed to the earth gradient (difference) between his feet—known as step potential. Any contact between an employee standing on the ground and touching a piece of equipment grounded to the system is subject to injury by touch potential. The only way to ensure against these conditions on the ground is for all grounded equipment to be surrounded by equipotential mats (required by OSHA 1910.269 (p)(4)(iii)[C][4]) where access to and egress from the mat is done by hopping, as opposed to stepping, so that the feet are never touching the mat and the earth at the same time, or by all ground personnel wearing dielectric overshoes.

A FINAL POINT
The more resistance you build into your protective ground, the more current there will be across your body in case of a fault. Ground it, but ground it right and ground it well! ip