another electricution - metal street pole-baltimore!

[charlie tuna]

Re: another electricution - metal street pole-baltimore!

because it reduces the number of bond wires in the connection compartment and removes the theory to the installer/and or maintainance person that the green wire from the poles ground rod has a function in reguard to a return path to the power source.

 

[tom baker]

Re: another electricution - metal street pole-baltimore!

There is no problem with ground rods at metal lighting poles. The problem is persons thinking they will clear a line to pole fault which they will not.

 

[petersonra]

Re: another electricution - metal street pole-baltimore!

Originally posted by charlie tuna:
because it reduces the number of bond wires in the connection compartment and removes the theory to the installer/and or maintainance person that the green wire from the poles ground rod has a function in reguard to a return path to the power source.

It seems to me that educating them is a better answer. They will be much safer if they understand why they are doing what they are doing, rather than having an arcane rule that does not seem to make much sense.

 

[physis]

Re: another electricution - metal street pole-baltimore!

Charlie T,

I agree completely with Tom and Bob. There's not a thing wrong with "earthing" the pole, it's less safe otherwise.

I'm convinced that the lack of understanding behind a lot of miswirings stems from too much use of the word ground in so many different forms.

I'm really going a little too far in saying this but with every wire in there having the word ground in it, how could it not be grounded?

But the confusion comes from the language, not the ground rod.

 

[physis]

Re: another electricution - metal street pole-baltimore!

Don, I brought this from the backward motor thread because this whole topic has a bit of a contaminating effect.

By Don:

Sam,
The word "equipment" in equipment bonding jumper is required because there are other types of bonding jumpers.
Don

I thought you were talking about equipment grounding conductors?

Anyway, in my opinion, for continuity of thought, isn't it easier and also accurate to think of the bonding system as whatever mechanicly and electricly connected elements being bonding conductors?

Edit for UBB code repair

[ January 04, 2005, 05:55 PM: Message edited by: physis ]

 

[charlie tuna]

Re: another electricution - metal street pole-baltimore!

we have all read about deaths from electrified poles with the ground rod being the only means to remove the voltage from the pole's metallic surface. and i have never seen a reduction in damage to equipment from poles stuck by lightning that have ground rods installed. looking at what is happening in the trade, i don't see any future improvement requirements to those servicing them. since we have more poles installed every year we can expect the deaths to increase. most of the people maintaining these poles are not required to be licensed. if the ground rod really hasn't a function, why have it? or if we assume it has a function --- why don't we drive two ground rods like on services? we are killing too many people on these installations and not reacting as an industry. we reacted to change the code on "vending machines" due to three deaths! three deaths in the whole country. on utility poles we kill three people or more in each state! lets face it, if the vending machines involved in these three deaths were properly grounded, how could they have caused a death?

 

[charlie]

Re: another electricution - metal street pole-baltimore!

Mr. Eldridge, that's true, and I'm sure . . .

Sam, if I am not Charlie, we can't be friends.

Charlie Tuna, why do you feel like it is dangerous to use supplementary grounding that is installed and maintained by qualified persons? Assume I have a piece of electronic equipment that is not working right, I decide to change some of the tubes, I don't know much about it but I remove the back anyway, I stick my hand into B+ (whatever that is), and end up in the hospital. Should I be suing Philco for faulty equipment?

lets face it, if the vending machines involved in these three deaths were properly grounded, how could they have caused a death?

Charlie, I agree with that statement.

 

[George Stolz]

Re: another electricution - metal street pole-baltimore!

How do you bond a utility pole like that? What is the other end connected to?

I'm seeing reams of discussion about sloppiness and ignorance and whatnot, and I am saying I am ignorant of this! What's the right answer? You all know it, take it for granted and noone's said it yet!

 

[charlie tuna]

Re: another electricution - metal street pole-baltimore!

quote:Charlie Tuna, why do you feel like it is dangerous to use supplementary grounding that is installed and maintained by qualified persons?

if the ground rod has a high impedance to that of the power source - which most do - it cannot be considered a "supplemental ground" --- that is the actual problem in many electrocutions! too many qualified and unqualified installers and maintainance people consider the ground rod has a low enough impedance to carry the fault current to clear the circuit!

[ January 04, 2005, 09:26 PM: Message edited by: charlie tuna ]

 

[ken987]

Re: another electricution - metal street pole-baltimore!

For anyone here that thinks that traffic signals and light poles are maintained by qualified people, YOU ARE WRONG. They maybe able to get the light to light and the signals to work, however they do not understand bonding, and that the ground rod will not clear a fault.
How do I know this because I work with them. OH the stories I can tell and I've only worked at this place for a year. Where I work the blind are leading the blind. I routinely run into improperly bonded electrical equipment, that was serviced by what the state of NJ considers QUALIFIED ELECTRICAL MECHANICS.
One example,
Two guys were working together trouble shooting tower lighting at an interchange. (The way these fools look for a short is to just start cutting wires and try and reset the breaker).
Anyway the LEAD mechanic who has been there 12 years can't understand the difference between line and load. So they cut all 3 of the wires that he thought would be the set being disconnect by the breaker, well those wires were not the load side, they were the line side and those retards for a few minutes had no idea that they cut a 277/480 feeder for the panel. Mind you their kneeling on the ground leaning into a pull box with a metal ring around the top.
These are the same people that bond traffic poles.

 

[charlie tuna]

Re: another electricution - metal street pole-baltimore!

stolzy,
what we are talking about is the requirement to drive a ground rod at light poles. it was a practice carried over from utility installations and spread into the outside commercial trade. then it was thought to reduce lightning damage which has not been proven. too many people consider this ground rod a good return path back to the power source. we have found out it is a very poor path and usually usless! many of the people maintaining these installations are not licensed and not required to attend classes where they could possible gain the knowledge to properly maintain these poles to be safe. also the metering equipment necessary to confirm a good low impedance path is expensive and not available to these people.

consider a typical installation where two 277 volt circuits enter a pole and leave that same pole. the pvc raceway has four wires from the source and four wires leaving the pole to the next pole in the circuit. so in the pole junction box we have two browns, two yellows, two whites, and three greens. one of these greens comes from the ground rod driven next to the pole. lets say this pole is connected to the yellow circuit and the poles are 277 volts. consider that this pole is now ten years old --- road dirt--wires discolored ---just nasty--hay-normal. drunk driver hits the pole and shears it off at the base. pole goes down the road and the wires are torn apart. you are now sent out to correct the problem---make this safe and connect the system back so that the other poles down stream operate. you come across three green wires--how do you confirm that you have a low impedance return path to the power source ---which wire is which? or did the actual low impedance conductor get pulled loose in the previous pole?

there are many possibilities here -- we may not have any actual return path and the jerking of the brown wire when the car hit the pole may have energized another pole? too many people working on these poles do consider the ground rod conductor the best return path.

what we are discussing is the ground rod a useful item in this installation and how do we educate those people maintaining these installations?

stolzy, i hope this helps you understand this issue.

 

[physis]

Re: another electricution - metal street pole-baltimore!

No offence intended Charlie. I use Ma'am, Sir, Mr. and Mrs. as a matter of typical convention in my non-virtual life. Completely a matter of respect.

 

[dillon3c]

Re: another electricution - metal street pole-baltimore!

sam, I catch myself saying it all the time too. It's just respect...

 

[George Stolz]

Re: another electricution - metal street pole-baltimore!

Thanks, Charlie Tuna. But I'm not visualizing this 100%. So the poles are fed from a meter somewhere, each pole has a rod, and the 3 greens you refer to are upstream ground-rods and service, downstream ground rods, and the ground rod for the pole we're on. Why would a person pick and choose, why not bond the three greens together?

Are you guys just discussing the big picture, the lack of checking the conductors on the last and next pole in the event they have been tugged?

My questions will hopefully lead me to understanding why you'd eliminate ground rods at each pole and only use the grounding electrode at...the meter?

 

[charlie tuna]

Re: another electricution - metal street pole-baltimore!

because what we are trying to do is maintain a low resistance path from the metallic parts of the pole back to the power source so that if a phase conductor comes in contact with any of these metallic surfaces it will cause the overcurrent device to operate and turn the circuit "off"!

consider the ground rod is ten feet long--the water table is three feet down - so the rod has seven feet of it's surface in contact with water. mike holt's grounding and bonding class shows him connecting a 120 volt circuit to a ground rod at his home in florida. he puts an amp probe on it and it draws about 1.5 amps. then they add another ten foot section to the ground rod and drive it down to twenty feet or seventeen feet of rod in contact with the water ---take another reading and it's about 3.5 amps---the final section was fifty foot down and the current draw was about 13.7 amps! still not enough to trip the circuit and clear a typical ground fault! keep in mind that the current is trying to get back to the power source -- in his case ---back to the transformer secondary on his power pole. this is a factor of the resistance between the power pole and the ground rod!

i was shocked to see this demenstration---ground to me was always completely thought of being zero at any ground rod! i have used this theory during my years in the trade and for years i have been wrong!!! i can remember telephone people wanting grounds at their phone boards. no-no --not a ground rod---they wanted a number six ran back and attached at the panel feeding the receptacles at the phone board! i used to think "how dumb" these people are! i was the dummy!

have you ever found that a ground rod at a light pole prevented or minimized damage to the electrical system? knowing lightning is unpredictable and the damage can be large or small, i have never seen much difference since this ground rod at the pole has been practiced. i would like other information on this if you feel different?

 

[physis]

Re: another electricution - metal street pole-baltimore!

Charlie T,

If the workers who are wiring these don't understand how to deal with a ground rod I don't see how they're going to understand bonding the pole either. Come to think of it, maybe they don't.

So are you saying that by removing the ground rod the workers will suddenly know how to bond the pole?

Two guys at a pole.
I'm picturing a guy scratching his head.
Another guy taking the ground rod, throwing it aside.
The first guy now nodding affirmatively, going "oh, ok, I see".

But I'm not beleiving that for a second.

 

[charlie tuna]

Re: another electricution - metal street pole-baltimore!

mr. physis sir,
"get the ladder and big hammer, we gotta drive the ground rods at the light poles"

"no, thats not required anymore"

"but i thought the ground rod was the most important part of the grounding installation"

"no, they found out they are useless"

"whats gonna take it's place"

"i don't know, but thats one less wire we have to contend with"

"maybe the inspector knows something about it"

"don't ask him anything, he's bad enough as it is"

"they ain't on the plans anymore, see!"

"maybe the boss can tellus?" "he goes to those mike holt seminars!"

 

[iwire]

Re: another electricution - metal street pole-baltimore!

Charlie, I can not agree with you that if ground rods at poles where eliminated the problem would be solved.

I really think that is far fetched, sorry but that is just my opinion.

The fix is education.

The only way education will happen is when the power companies are held to the fire for these incidents.

Bob

 

[iwire]

Re: another electricution - metal street pole-baltimore!

Charlie it just struck me that you are against HIs looking at electric equipment because they are unqualified.

But you want to make a change in procedures so unqualified people can continue installing electric equipment. Even though the change you recommend will not make the installers any more educated.

I do agree with you that these electrocutions are a serious issue that needs addressing

Bob

[ January 05, 2005, 04:26 PM: Message edited by: iwire ]

 

[physis]

Re: another electricution - metal street pole-baltimore!

Good catch Bob, It's so obvious I missed it.

Charlie T., I'm not trying to get you riled up, I just don't beleive that removing a ground rod will improve anything.

Edit: But we do agree on other points!

[ January 05, 2005, 04:53 PM: Message edited by: physis ]