250.32(A) vs 250.50 for 1 circuit

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transman2

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Question,

I have a high mask light pole that has some I.T. equipment mounted about half way up with equipment mounted in a plastic nema box with a metal back plate located at base of pole that we have to run an underground circuit (120V) for a duplex receptacle. Engineering did not put in the spec's for the EC to bond to the ground rod at the pole that is present from the metal back plate.

Correct me if I'm wrong but I know there is an Exception under 250.32(A) saying a ground rod is not required for 1 circuit but 250.50 says that if a electrodes are present per 250.52 (A)(1)-(A)(7) at each building or structure served shall be bonded together to form a grounding system. It also says if none exist, one or more specified in 250.52(A)(4) through (A)(8) shall be installed.

With this being said should 250.50 code, rule over the 1 circuit code in 250.32(A). Sorry for making this so long.
 
It appears that you have more than one circuit feeding the pole, so the one circuit exception in 250.32(A) would not apply.
 
don_resqcapt19 said:
It appears that you have more than one circuit feeding the pole, so the one circuit exception in 250.32(A) would not apply.
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Ok, so your looking since the pole has lighting circuits coming to it and the box is attached to the structure that equals more than one circuit. Fair enough, sounds good and will tie into system. However what if its a structure with no other circuits and where running only 1 circuit. Doesn't 250,50 still apply. "Where none of these electrodes exist, one or more shall be installed. It just seems like it would the right way to do it. Not unless someone understands this better.
 
As I read the OP the pole appears to be electrical equipment IMO not a structure -- same as a pedestal meter/main
 
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mwm1752 said:
The pole is electrical equipment IMO not a structure
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Sorry I would have to disagree, the pole is a structure. Please read the definition of structure in the code book. The pole also sits on another structure sometimes that's formed with rebar. Electrical is attached to this structure also.
 
mwm1752 said:
As I read the OP the pole appears to be electrical equipment IMO not a structure -- same as a pedestal meter/main
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Probably not the best example seeing how a meter pedestal will have a GE. :D

Roger
 
transman2 said:
Ok, so your looking since the pole has lighting circuits coming to it and the box is attached to the structure that equals more than one circuit. Fair enough, sounds good and will tie into system. However what if its a structure with no other circuits and where running only 1 circuit. Doesn't 250,50 still apply. "Where none of these electrodes exist, one or more shall be installed. It just seems like it would the right way to do it. Not unless someone understands this better.
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It is my opinion that the rule in 250.32 governs when there is a single branch circuit that feeds a structure. It acts as an exception to 250.50. Note that the permission to eliminate the grounding electrode at the second structure applies only when that structure is fed by a single branch circuit. It does not apply where the structure is fed by a feeder, or by multiple branch circuits.
 
don_resqcapt19 said:
Both of those items are "structures" per the NEC definition.
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Equipment. A general term, including fittings, devices, appliances, luminaires, apparatus, machinery, and the like used as a part of, or in connection with, an electrical installation.

Luminaire. A complete lighting unit consisting of a light source such as a lamp or lamps, together with the parts designed to position the light source and connect it to the power supply. It may also include parts to protect the light source or the ballast or to distribute the light. A lampholder
itself is not a luminaire.

Then we can agree to disagree -- The reference to pedestal had to do with an email from Jeffery Sargent some years age during a web cast. I asked if a pedestal was a "structure" which is referenced in a feeder from structure to structure. His answer was no it was electrical equipment.

Structure. That which is built or constructed.

Every object in the world not naturally occurring is built or constructed if you want to define it as such. Installing a run of EMT with fittings is built or constructed if you want to define it as such.
 
The OP might skirt by the electrode issue by making the supply a MWBC which by Code is still considered a single circuit
 
mwm1752 said:
Equipment. A general term, including fittings, devices, appliances, luminaires, apparatus, machinery, and the like used as a part of, or in connection with, an electrical installation.

Luminaire. A complete lighting unit consisting of a light source such as a lamp or lamps, together with the parts designed to position the light source and connect it to the power supply. It may also include parts to protect the light source or the ballast or to distribute the light. A lampholder
itself is not a luminaire.

Then we can agree to disagree -- The reference to pedestal had to do with an email from Jeffery Sargent some years age during a web cast. I asked if a pedestal was a "structure" which is referenced in a feeder from structure to structure. His answer was no it was electrical equipment.

Structure. That which is built or constructed.

Every object in the world not naturally occurring is built or constructed if you want to define it as such. Installing a run of EMT with fittings is built or constructed if you want to define it as such.
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If the code did not consider the light pole to be a structure, there would be no reason for Exception #3 to 225.32 to be in the code. It is not the luminaire that is the structure, it is the pole that supports the luminaire.

Just because Mr Sargent says it is not a structure does not mean it is not a structure. There are a number of other code authorities that say it is. The only real answer would be from your AHJ or from a formal interpretation issued by the NFPA.
 
augie47 said:
The OP might skirt by the electrode issue by making the supply a MWBC which by Code is still considered a single circuit
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GoldDigger said:
...Which by the code *may* be considered as a single circuit. You have options.

Tapatalk!
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And 225.30 requires a structure to be supplied by one feeder or branch circuit unless permitted by (A) through (E). This install would be permitted if the luminaires and other equipment are of different characteristics (voltage?)... but otherwise would be a violation to supply with two branch circuits.
 
The exception to 250.32(A) says that for the purposes of the exception a multiwire branch circuit is a single circuit.
 
don_resqcapt19 said:
The exception to 250.32(A) says that for the purposes of the exception a multiwire branch circuit is a single circuit.
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True.

However, I realized another condition which would permit two circuits: where the lighting is remotely controlled, such as with a timer and/or photocell, or simply turning on and off with a remotely-located switch or breaker.
 
Maybe we are discussing different versions of a light pole -- my version is one that is manufactured as part of the luminaire -- Is your version a power pole with a luminaire attached?
 
mwm1752 said:
Maybe we are discussing different versions of a light pole -- my version is one that is manufactured as part of the luminaire -- Is your version a power pole with a luminaire attached?
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Either way, if a pole supports the fixture it is a structure because it was in fact built or construted.
 
All of these poles are separate structures to the NEC.

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