Grounding Rods for Signs

[sign-girl]

Hi, I'm having trouble finding requirements for grounding rods (lightning protection) for pylon signs/electric signs in UL 48 or the NEC code. What are the rules for lightning protection? If not required, when is it appropriate to include grounding rods for lighting protection? What are your experiences with this? Any input is appreciated. Thanks!

 

[tom baker]

NEC does not require lightning protection. There are some rules in Art 250.54, 250.60. There is an entire NFPA standard on lightning protection and we have many forum members who install those systems. Where I live, near Seattle, lightning is not a issue.

 

[sign-girl]

Tom, Thank you for the quick response! I'm reviewing those articles now. I look forward to hearing specifics from any forum members who are familiar with these systems. Thank you!

 

[cowboyjwc]

The sign is pretty much a ground rod it's self.

 

[sign-girl]

HaHa! Thanks John. I tend to agree with you. We are told the electrical inspector on this particular site will not approve the sign without lightning protection. It's a 19' tall pylon with LED illumination. We are working with a master electrician to guide us through the process which seems pretty straight forward. I would continue to accept peoples input, especially if there are other sign professionals who may have come across this. I'm wondering if this is standard for this type of unit, if it is good common practice and/or if this is a case of an overly strict inspector? Thank you!!

 

[pete m.]

In your situation I would politely ask the inspector for the legally adopted code requiring it.

Pete

 

[petersonra]

In your situation I would politely ask the inspector for the legally adopted code requiring it.

Pete

It is a separate structure. That would seem to require that it have some kind of grounding electrode system unless it meets the exception of having only one branch circuit.

see 250.32.

The inspector may believe the grounding electrode system is required for lightning protection, but that is not the reason it would be required.

 

[sign-girl]

Pete, That's a good idea. Thanks

 

[sign-girl]

Bob,
I looked at 250.32. The exception would apply since there is only one branch circuit feeding the sign. Extremely helpful. Thank you!

Kat

 

[jxofaltrds]

'If' your pole's base meets 250.52(A)(3) do you install the ground rod per 250.53(A)(3)?

 

[MasterTheNEC]

'If' your pole's base meets 250.52(A)(3) do you install the ground rod per 250.53(A)(3)?

No and Why?

I am assuming you know this and are simply asking the OP if they know this.....

If the pole base meets the specific requirements of Section 250.52(A)(3) then any additional GE would be unnecessary as you indeed know....provided the AHJ understands and can verify that the pole base does meet this requirement since chances are when they arrive on the job the base has long been poured. He may choose to communicate with the building inspector who did the base inspections or might even be the same dude...Here is what Section 250.50 says...

250.50 Grounding Electrode System. All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building or structure served shall be bonded
together to form the grounding electrode system. Where none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(8) shall be installed and used.

Again...if the Base Complies (and accepted) then adding anything else is overkill...but many elect to go above minimum code....have at it, we sell more wire the more you add:thumbsup:

 

[pete m.]

Recently did an inspection on a 40' sign with a LED message center. The sign head was supported on a steel tube approximately 2' in diameter and maybe 15' in the ground encased in concrete.

The sign installer drove an 8' ground rod next to the sign base. I asked why and he said that the manufacturer of the LED message center would not honor the warranty unless a ground rod was installed.:?

Pete

 

[GoldDigger]

Recently did an inspection on a 40' sign with a LED message center. The sign head was supported on a steel tube approximately 2' in diameter and maybe 15' in the ground encased in concrete.

The sign installer drove an 8' ground rod next to the sign base. I asked why and he said that the manufacturer of the LED message center would not honor the warranty unless a ground rod was installed.:?

Pete

Well, the concrete did not contain rebar and the metal did not meet the 20' length requirement. So you can argue that it was not a CEE under the Code. And, being encased in concrete it would not be a rod, pole or plate electrode.
It would be nice if the NEC recognized a few more types of electrodes, but I am not going to try to formulate a comment.

 

[pete m.]

Well, the concrete did not contain rebar and the metal did not meet the 20' length requirement. So you can argue that it was not a CEE under the Code. And, being encased in concrete it would not be a rod, pole or plate electrode.
It would be nice if the NEC recognized a few more types of electrodes, but I am not going to try to formulate a comment.

I believe the pole would qualify as a grounding electrode in accordance with 250.52(A)(2)(1). It just seemed strange to me that the manufacturer would require a ground rod when the surface contact area of the sign structure to the earth is immense in comparison to a rod.

Pete

 

[GoldDigger]

I believe the pole would qualify as a grounding electrode in accordance with 250.52(A)(2)(1). It just seemed strange to me that the manufacturer would require a ground rod when the surface contact area of the sign structure to the earth is immense in comparison to a rod.

Pete

It seems simple enough to me. The manufacturer of the message center has no idea what sort of structure it will be installed in.
Unfortunately they chose to require a ground rod instead of simply specifying an NEC-compliant ground system.

 

[Cavie]

I think that the concrete and steel required for a pylon sign is in it's self a pretty good Urfer ground.

 

[GoldDigger]

I think that the concrete and steel required for a pylon sign is in it's self a pretty good Urfer ground.

I agree, but the NEC does not recognize that.
Unless you are willing to call it building steel. (Which includes aluminum?)

 

[sign-girl]

Thank you everyone for your valuable input!

 

[jxofaltrds]

No and Why?

I am assuming you know this and are simply asking the OP if they know this.....

If the pole base meets the specific requirements of Section 250.52(A)(3) then any additional GE would be unnecessary as you indeed know....provided the AHJ understands and can verify that the pole base does meet this requirement since chances are when they arrive on the job the base has long been poured. He may choose to communicate with the building inspector who did the base inspections or might even be the same dude...Here is what Section 250.50 says...

250.50 Grounding Electrode System. All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building or structure served shall be bonded
together to form the grounding electrode system. Where none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(8) shall be installed and used.

Again...if the Base Complies (and accepted) then adding anything else is overkill...but many elect to go above minimum code....have at it, we sell more wire the more you add:thumbsup:

Yes and if the ground rod is installed 6' away from the base.