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Ground Rods for Temporary Power on a Construction Site [VIDEO]

jar546 said:
Yes, per the definition of Equipment and as discussed and confirmed by CMP-1, hence for the change in the definition of Structure for the 2017 NEC. The Code Making Panel 1 (CMP-1) specifically pointed out the phrase "...and the like" in the definition of equipment. One of the reasons the change to the definition of the word Structure even happened was to clarify that ground rods were not needed for situations such as the one presented in this thread.
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So is it listed and labelled? How do you approve it for that use? Engineering for the "pedestal" or accepted trade practice?

(B) Installation and Use. Equipment that is listed, labeled, or both shall be installed and used in accordance with any instructions included in the listing or labeling.
 
steveray said:
So is it listed and labelled? How do you approve it for that use? Engineering for the "pedestal" or accepted trade practice?

(B) Installation and Use. Equipment that is listed, labeled, or both shall be installed and used in accordance with any instructions included in the listing or labeling.
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Not all equipment is required to be listed and labeled. We can start there. The NEC does require some specific equipment to be listed and labeled, but not all.

Eluding to your post, you are correct that: Listed or labeled equipment shall be installed and used accordance with any instructions included in the listing or labeling. What that means is that IF you use listed or labeled equipment, then yes, it applies. At no point does that section state that you have to use listed and labeled equipment.

For example, NEC 406.3(A) states that receptacles shall be listed. The same goes for the fittings of EMT & its fittings under NEC 358.6. There are plenty of listing requirements for certain equipment.

Now lets look at NEC 314 which involves different types of boxes and enclosures. The only boxes required to be listed are those that are located in a wet location. Dry locations do not require the boxes to be listed. Then there are the ground rods used as a GEC. They are not required to be listed or labeled.

If I were inspecting the temp power under the 2014 NEC, a GECS would be required, just not under the 2017 NEC or newer.
 
jar546 said:
Not all equipment is required to be listed and labeled. We can start there. The NEC does require some specific equipment to be listed and labeled, but not all.

Eluding to your post, you are correct that: Listed or labeled equipment shall be installed and used accordance with any instructions included in the listing or labeling. What that means is that IF you use listed or labeled equipment, then yes, it applies. At no point does that section state that you have to use listed and labeled equipment.

For example, NEC 406.3(A) states that receptacles shall be listed. The same goes for the fittings of EMT & its fittings under NEC 358.6. There are plenty of listing requirements for certain equipment.

Now lets look at NEC 314 which involves different types of boxes and enclosures. The only boxes required to be listed are those that are located in a wet location. Dry locations do not require the boxes to be listed. Then there are the ground rods used as a GEC. They are not required to be listed or labeled.

If I were inspecting the temp power under the 2014 NEC, a GECS would be required, just not under the 2017 NEC or newer.
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Got it Jeff, and I know I'm being a bit of a jerk....But that was my point...I don't know if unistrut is listed or what it is listed for....I know it doesn't need to be, what I am seriously asking is if you get a design or if it just whatever the electrician wants to throw together? Our utility has "temp pole" specs which I would reference on a "non utility" setup if I had to...

And do you bond it per 250.4A 3-5?...I know it's a little OT maybe but figured we could hash out all of the details on a "Temp not service supported on a metal not structure" while we are here....
 
From a strictly theoretical perspective, driving ground rods when you already have a properly sized EGC back to a good, existing grounding electrode has no measurable benefit.
 
Exactly right. You could have a massive factory with giant subpanels fed from a 1/4 mile away in the same building, and no additional grounding electrodes are required. But a garden shed with a couple circuits 3' from your house needs its own grounding electrode system... Maybe someone smarter than me can explain that one....
 
Beniah Naylor said:
Exactly right. You could have a massive factory with giant subpanels fed from a 1/4 mile away in the same building, and no additional grounding electrodes are required. But a garden shed with a couple circuits 3' from your house needs its own grounding electrode system... Maybe someone smarter than me can explain that one....
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As long as those subpanels don't supply a structure.....That severely limits the applications
 
steveray said:
Can't be used outdoors...

384.10 Uses Permitted.

The use of strut-type channel raceways shall be permitted in the following:
  • (1)
    Where exposed.
  • (2)
    In dry locations.
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Unless it is not listed for strut-channel and just used a channel. I've installed a lot of galvanized and stainless steel channel that is still part of the electrical equipment. They do have strut-channel (if used as conduit) for wet use.
 
steveray said:
I could call the "rack" a structure if I wanted to
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It seems to me that I recall a definition in a code book for the word structure as “supporting a use”. I could be wrong about that and if it’s not there now it makes no difference however, there needs to be a line drawn somewhere. A snowman is a structure as is a dollhouse. Practitioners of code enforcement require a use.
 
jar546 said:
Unless it is not listed for strut-channel and just used a channel. I've installed a lot of galvanized and stainless steel channel that is still part of the electrical equipment. They do have strut-channel (if used as conduit) for wet use.
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So again, should we be bonding all unistrut as equipment?

(2) Grounding of Electrical Equipment.
Normally non-current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected to earth so as to limit the voltage to ground on these materials.

ICE said:
It seems to me that I recall a definition in a code book for the word structure as “supporting a use”. I could be wrong about that and if it’s not there now it makes no difference however, there needs to be a line drawn somewhere. A snowman is a structure as is a dollhouse. Practitioners of code enforcement require a use.
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I give it a U....like a cell tower.....
 
steveray said:
So again, should we be bonding all unistrut as equipment?
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If you watch the video, you will see that the panel is directly connected to the strut by mechanical means and since this is a subfeed, the EGC is separated from the neutral and bonds them all together to ground. You know there are times you must use common sense as an inspector and make sure you see the forest through the trees.
 
jar546 said:
You know there are times you must use common sense as an inspector
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Which is kind of my point Jeff...the NEC seems hell bent on eliminating any judgement or risk to the end of writing bad code or code that flip flops cycle to cycle...2017 1 receptacle per island, 2020 1 per 9sqft, 2023 none but if you have them they have to be on top.....2020 GFCI the A/C equipment unless its a minisplit, 2023..well it all gets a pass to 2026...And we won't go back down the working clearance and the rest of the GFCI/AFCI stuff....We can't preach "common sense" and then bash people for not following the code as written....
 
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