pole lights

[clintdenver]

I recently installed 5 new steel 25' 200 w MH pole lights operating at 208 volts. I pulled an egc to each location and bonded each pole to the egc. The inspector insisted that I am required to have a ground rod at each pole. I told her that I had searched in 410 and 250 and was unable to locate such a code. Have I over looked it? :?

 

[jwelectric]

no

 

[Pierre C Belarge]

That typically would be considered a "SUPPLEMENTARY" type of electrode as per 250.54. It is not an NEC requirement. Usually it is "speced" on the prints or specification sheet if there are any.

Ask her if there are local amendments to the code... then ask her for it in writing - Ms inspector what section number is that so i can look it up and memorize it

 

[haskindm]

Are the poles mounted on a reinforced steel concrete base? If so ask the inspector to read the definition of a "concrete encased electrode", then ask why you would need to supplement a concrete encased electrode with a ground rod? Also ask what section of the code you are violating. She may cite 250.50 or 250.32(A) which requires a grounding electrode at each "structure". If she insists that the concrete base does not meet the requirements of a concrete encased electrode, then you may point out that 250.32(A) Exception eliminates the requirement for a grounding electrode if the "structure" is served by only one branch circuit. I assume you have fed each pole with only one branch circuit. Now, if the specifications require a ground rod at each pole, then you are required to install it in order to meet the specs, not to meet the NEC. This is one of those issues that has been accepted and nobody questioned, but it is NOT an NEC requirement.

 

[cowboyjwc]

The problem use to be that inspetors considered light poles as structures as per the definitions.

Per the NEC you are not required to supply a seperate ground rod at each pole and that was in the analysis either last time or the time before.

In the 2002 analysis it talks about 250.24. "Supplementary grounding electrodes shall be permitted to be connected to the equipment grounding conductors specified in 250.118 and shall not be required to comply with the electrode bonding requirements of 250.50 or 250.53(C)....."

So it is not required, but it is permitted. Now I have had some Engineers from back east require ground rods for lightning, or have a coil of copper in the footings. If it is an engineered design then you may have to install them.

 

[clintdenver]

The specs aren't requiring any supplementary ground. I spoke with her today and she claimed that she wants to see it anyway. She seems to think that a ground rod with >25 ohms is a better path to ground than the egc. I suppose that it wouldn't hurt in case of lighting, but the ecg will still be the path of least resistance. I am I wrong?

 

[raider1]

She seems to think that a ground rod with >25 ohms is a better path to ground than the egc. I suppose that it wouldn't hurt in case of lighting, but the ecg will still be the path of least resistance. I am I wrong?

The earth can't be used for a ground fault current path (see 250.4(A)(5)). The egc must be used for the bonding requirements of 250.4(A)(3) (unless 250.32(B) applys)

Also a light pole is considered a structure according to article 100 definitions. The exception for a grounding electrode at a light pole is 250.32(A) Exception. This exception says that a structure that is fed with a single branch-circuit that includes an equipment grounding conductor need not have a grounding electrode.

You are correct that the ground rod wouldn't hurt in case of lightning, but would pretty much serve no other purpose at a properly bonded light pole.

Chris

 

[tshea]

he claimed that she wants to see it anyway. She seems to think that a ground rod with >25 ohms is a better path to ground than the egc

Two choices:
1. Rollover and take it through the wallet.
2. EDUCATE her. First have her cite the violation, then counter with "not true" here is the Analysis of Changes in the 2002(5) NEC which specifically recommends against it.

$10 ground times 5 = $50
Labor at $75/hr times 5 rods =$375
Misc parts 10/pole = $50
Educate an inspector and gain new respect = PRICELESS

 

[Pierre C Belarge]

Tshea


"$10 ground times 5 = $50
Labor at $75/hr times 5 rods =$375
Misc parts 10/pole = $50
Educate an inspector and gain new respect = PRICELESS"



Very clever 8)

 

[George Stolz]

That typically would be considered a "SUPPLEMENTARY" type of electrode as per 250.54

For now... :twisted:

The specs aren't requiring any supplementary ground. I spoke with her today and she claimed that she wants to see it anyway.

Well, it's hard to argue that point. It's irrational. Let us know what you decide to do.

Educate an inspector and gain new respect = PRICELESS

Some aren't looking for an education, and repay that offer in pain.

At this point in life, I would drive the rods and forget about it. I would develop a serious facial tick, but I would learn to cope with it.

 

[tshea]

Some aren't looking for an education, and repay that offer in pain.

Come on..I was trying to be nice.

At this point in life, I would drive the rods and forget about it. I would develop a serious facial tick, but I would learn to cope with it.

Not me!

Is that code? Well no, but I want it that way.
Give me the code reference so I can justify to the owner the additional cost.
Good day, madam!

 

[infinity]

I'd say fight her on this. This is a black and white argument. She's incorrect. If she really believes this:

She seems to think that a ground rod with >25 ohms is a better path to ground than the egc.

Than she needs a lot of education.

 

[charlie b]

She seems to think that a ground rod with >25 ohms is a better path to ground than the egc.

Actually, that is true. :shock: Irrelevant, but true. :shock: :?: :?:

Before anyone starts typing a scathing reply, let me observe that the current flowing to the load, and from there through any postulated fault on the pole, is not trying to find its way to planet Earth. It is looking for its source, and the EGC is the best path to the source. In fact, as others have pointed out, we are not permitted to take credit for planet Earth as a path for conveying fault current back to the source. That is why her statement is irrelevant.

But lightning IS trying to find its way to planet Earth. If it sees a ground rod right at the pole, and if it also sees a bonded EGC at the pole that leads to ground bar at the service panel and from there (via the GEC) to the service's ground rod, then yes, the better path would be via the ground rod at the pole. That is why her statement is true. But lightning is going to go from the pole directly into dirt, especially if the pole has a steel-reinforced concrete base (as haskindm mentioned). It is also going to go to dirt via the EGC and GEC. Adding another path for lightning to take to dirt does not make the installation safer in any way. That is another reason her statement is irrelevant.

 

[charlie b]

I'd say fight her on this.

I agree completely.

 

[iwire]

The problem use to be that inspectors considered light poles as structures as per the definitions.

A pole light is a structure to the NEC.

You would have to have a disconnecting means at it if the NEC did not put in exception specifically for this. 8)

If it was supplied by two circuits it would have to have an electrode as much as it would not help. :roll:

 

[clintdenver]

The poles are feed by a single circuit.
Anyway, I chose not to fight this battle. I left her a message informing her that there wasn't a code requirement stating a supplementary ground was necessary, but I will comply with her request. There are two reasons I choose to go this route, first the job had money left in it and secondly the apartment manager was smokin hot. It turned out all right; the inspector is happy and I got a date for Saturday. :mrgreen:

 

[GalwayElectric]

Not sure if this is relavent but a friend of mine does nothing but street lighing in NYC. Every poll has a the ECG bonded to a ground rod at each location.

 

[charlie tuna]

this subject has been hashed over many times --- i would like to ask you all if it has ever been your experiance that you actually witnessed a lightning strike on a pole, that in your oppinion, the driven ground rod protected the system and provided a positive function?

i have been involved with maybe 15 or so lightning strikes on poles or outside lighting circuits. i have never seen that the ground rod has shunted or carried lightning current away from the system's equipment. it has blown the lighting contactors off the wall, blew the guts out of the outside lighting panel, blown the meter off the wall, and one instance the current jumped onto the elevator's metal raceway and burnt up the controls and also blew the elevator disconnect off the wall.

and in the recent five years that this ground rod issue has been around, i have really looked closely at the wire connections to the ground rod trying to determine if the insulation showed any discoloration or heat damage?? never found any!!! on the other hand the egc's wire show major damage many times. if any one has any comments lets hear from you.

it's nice that we get to sell these ground rods and increase our profits, but i believe the additional and useless(my oppinion) additional green conductor has been the cause of many electricutions. too many people(qualified and unqualified) have depended on the conductor connected to the useless ground rod to provide a return ground path to the source voltage. and the area of street lighting is continually being maintained by totally unqualified people in many areas. i read somewhere we kill about 350 people each year on street light poles in the united states.

looking into many of these cases, the sad thing is nobody learns from these deaths. take the average service truck and employee --- and place him at an accident sene where a car hits and shears off a street light pole at 2:00 A.M. .. he is called to make the pole safe and resplice the conductors to make the rest of the system operational. how does he determine the ground rod wire from the egc and confirm that they are intact? somebody gets sued --- and they forget it!!!

 

[scott thompson]

the inspector is happy and I got a date for Saturday.

That's so cool!!!

This is the first time I have read a thread with a "Storybook Ending"
(i.e.: They lived happily ever after)

Scott35

 

[Pierre C Belarge]

Not sure if this is relavent but a friend of mine does nothing but street lighing in NYC. Every poll has a the ECG bonded to a ground rod at each location.

The street lights in NYC are Utility supplied. The Utility uses the grounded conductor as a return to the supply (transformer). This is the same principle as using the neutral bonded at the service.