Grounding electrode required?

[infinity]

I get the single circuit or feeder to a detached garage since it's required to have a disconnecting means to disconnect the power from the garage, a piece of wood does not require the same protections, therefore the absurdity.

So, from the original post - we have temporary power supply [(2) 50A feeders], fed underground, and the equipment is installed on a post [vs. a pole]. This scenario does then require a grounding electrode system.

Regarding the OP you cannot have two receptacles installed on a separate structure fed from two different circuits period, forget about the GES. :roll:

 

[kwired]

The way things are written it leaves it up to us to become creative at times.

Take a detached garage with 10 circuits supplying it. Most will say clear violation of multiple feeds and the need for a grounding electrode system. Now take same installation and install a breezeway connecting the house to the garage - exact same electrical install is all in one structure now and there are no separate structure related code violations.

 

[iwire]

Now take same installation and install a breezeway connecting the house to the garage - exact same electrical install is all in one structure now and there are no separate structure related code violations.

IMO it would be up to local building codes / zoning to determine if that is one or two or maybe even three structures.

 

[iwire]

Here is an example I have seen in real life.

A business had two buildings on the same property, both buildings had electrical services. At some point a connection / bridge between the two buildings was made at about the third or forth floor level that contains a conveyor belt. The only access to the bridge is for maintenance of the conveyor. Other building workers cannot use it for crossing.

Still two buildings or one now?

 

[GoldDigger]

I vote 2 still. The connection is not structural to the buildings and does not provide access between them
There may be an issue regarding fire isolation, but nothing that would make it one building.

 

[Smart $]

I don't see how a piece of wood...

JMO... certainly debatable without resolution, but I think "structure" does not include a block of wood (post, pole, framework, etc.) which has the sole purpose of securing and/or supporting electrical equipment as required by Code. If the securing and/or supporting means has any additional purpose, only then would it qualify as a "structure". For example, adding a canopy.

 

[iwire]

without resolution, but I think "structure" does not include a block of wood (post, pole, framework, etc.) which has the sole purpose of securing and/or supporting electrical equipment as required by Code. If the securing and/or supporting means has any additional purpose, only then would it qualify as a "structure". For example, adding a canopy.

If that was the case there would be no need for the exceptions allowing the disconnecting means to be located remotly for fixture and sign supports

 

[Smart $]

If that was the case there would be no need for the exceptions allowing the disconnecting means to be located remotly for fixture and sign supports

Ahhh... perhaps refine "electrical equipment" to exclude utilization equipment...???

If we take the NEC definition of structure to the nth degree, conduit, cabling, etc. is also built or constructed, thereby such could be perceived as continuation of an existing building or structure. As Rob mentions, the definition is quite broad. As you mentioned, determine by building codes... but is a wood post with two receptacles fed by two circuits covered by those codes. I think not.

 

[iwire]

.. but is a wood post with two receptacles fed by two circuits covered by those codes. I think not.

You are free to think that but my example shows at least some CMP members do not think that and neither do I.

No one has yet to explain how the size of a structure changes electrical safety.

 

[Smart $]

You are free to think that but my example shows at least some CMP members do not think that and neither do I.

No one has yet to explain how the size of a structure changes electrical safety.

Structure size had no bearing in my stated opinion. I'm simply saying an installation or specific part thereof has to be distinguished as a separate structure before the requirements apply. Since you brought up the definition of structure being taken directly from building code, perhaps you can enlighten us with criteria building code uses to determine a separate structure that is not a building.

 

[iwire]

Structure size had no bearing in my stated opinion.

And you are not the only one I asked.

I'm simply saying an installation or specific part thereof has to be distinguished as a separate structure before the requirements apply.

I have no idea what you are saying.

Since you brought up the definition of structure being taken directly from building code, perhaps you can enlighten us with criteria building code uses to determine a separate structure that is not a building.

If it is built or constructed .... it is a structure.

All buildings are structures, not all structures are buildings.

So if it is not a building, (and I am not familiar with the building codes definition of a building) it is a structure.

 

[Smart $]

...
I have no idea what you are saying.

If it is built or constructed .... it is a structure.

All buildings are structures, not all structures are buildings.

So if it is not a building, (and I am not familiar with the building codes definition of a building) it is a structure.

Referring to picture below, excluding earth, grass, sky, everything else is built or constructed and physically connected through components. If you are going to distinguish any portion(s) as a separate structure, there has to be some criteria as the basis. For instance, exterior wire, cable, raceways are not considered part of a building or structure. Otherwise, we can take it from one extreme to the other: all of it is one structure vs. each component is a separate structure.

 

[infinity]

Part of the problem is that the NEC never had a definition of the word structure even though it was used within the code. Pretty much everyone knew what a separate structure was, the aforementioned tool shed, detached garage, guest house, pool cabana, etc. but that wasn't really good enough because it left a large amount of gray area. So the definition was taken from the building code but was never properly integrated into the NEC to cover arguments just like this thread.

Common sense would dictate that one block of wood with one receptacle is no less safe than the same block of wood with two receptacles or any less safe than two blocks of wood a 1/4" apart each with a receptacle. So until someone changes the definition of a structure to be more realistic and to reflect some common sense this debate will continue.

 

[kwired]

Here is an example I have seen in real life.

A business had two buildings on the same property, both buildings had electrical services. At some point a connection / bridge between the two buildings was made at about the third or forth floor level that contains a conveyor belt. The only access to the bridge is for maintenance of the conveyor. Other building workers cannot use it for crossing.

Still two buildings or one now?

Seen that many times myself, or maybe a second "building" gets added with it's own service but does connect to the first building. Local AHJ wants a 2 hr finish between the two "buildings" in order to allow second building to be supplied by a separate service. No branch circuits or feeders can originate in one "building" and supply the other "building". You can have open corridor between the two but must have automatic closing fire doors. You must also make sure you follow 230.2(E) requirements, even though it is kind of written to apply to a single building.

 

[Smart $]

Part of the problem is that the NEC never had a definition of the word structure even though it was used within the code. Pretty much everyone knew what a separate structure was, the aforementioned tool shed, detached garage, guest house, pool cabana, etc. but that wasn't really good enough because it left a large amount of gray area. So the definition was taken from the building code but was never properly integrated into the NEC to cover arguments just like this thread.

Common sense would dictate that one block of wood with one receptacle is no less safe than the same block of wood with two receptacles or any less safe than two blocks of wood a 1/4" apart each with a receptacle. So until someone changes the definition of a structure to be more realistic and to reflect some common sense this debate will continue.

:happyyes::happyyes::happyyes:

 

[Dennis Alwon]

We can all see the absurdity of it all. I wrote a proposal about septic pumps with alarms The units required 2 circuits however there was one structure.

The cmp stated that the circuits were feeding a piece of equipment not the structure so it was compliant.

One way around it is to add a small panel and then feed both pieces of equipment. Now you would need a grounding electrode conductor.

 

[don_resqcapt19]

...
The cmp stated that the circuits were feeding a piece of equipment not the structure so it was compliant.
...

So we can apply that same logic here....the circuits are not serving the structure, (the wood post), they are serving the equipment (the receptacles).

 

[kwired]

So we can apply that same logic here....the circuits are not serving the structure, (the wood post), they are serving the equipment (the receptacles).

As well as in a building - the circuits typically serve lighting, receptacles, utilization equipment.... not the building

 

[MasterTheNEC]

Here is an example I have seen in real life.

A business had two buildings on the same property, both buildings had electrical services. At some point a connection / bridge between the two buildings was made at about the third or forth floor level that contains a conveyor belt. The only access to the bridge is for maintenance of the conveyor. Other building workers cannot use it for crossing.

Still two buildings or one now?

My opinion is if the building consisted of a firewall that separated one from the other then it was two buildings. If you remove that separation then you do not maintain the fire wall between the buildings which is demanded by the IBC. Granted that creates an "after the fact" issue for the local AHJ....but in the purest sense of the International Building Code which is a higher stream of enforcement than the NEC in the AHJ world, you have taken two separate buildings and have created one building with the removal of a valid fire wall separation.

We can agree to disagree on that.......but thats how (I believe) 90% of the AHJ's will see it. Yeah, we always have that 10% radical faction roaming around that will agree with the "still" two buildings logic...:angel: