NEC 2014 250.64(F)

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hhsting

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In the attached picture I have bonding jumper from concrete encased electrode to structural steel and I also have GEC to the concrete encased electrode. NEC 2014 250.64(F) says to use 250.64(F)(1),(2) or (3). Would the attached be NEC 2014 Article 250.64(F) compliant?
 

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tom baker

tom baker

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Where the drawings says "In Conduit" please use PVC Sch 40 or 80. If you use metallic, its a lot of extra expense and work for no gain.
 
infinity

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Maybe this will help:

attachment.php
 
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jaggedben

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hhsting said:
In the attached picture I have bonding jumper from concrete encased electrode to structural steel and I also have GEC to the concrete encased electrode. NEC 2014 250.64(F) says to use 250.64(F)(1),(2) or (3). Would the attached be NEC 2014 Article 250.64(F) compliant?
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It's compliant with the 'or.' It is using (2), separate GECs to the UFER and the (non-required, oversized) ground rod.

You also have redundant bonding jumpers to the structural steel. But that's not and electrode or a GEC so it's not addressed by the section you cited. I know of no prohibition on redundant bonding jumpers, although perhaps objectionable current could be invoked. Might also have bad effects on the functioning of, say, audio equipment (ground loop).
 
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hhsting

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jaggedben said:
It's compliant with the 'or.' It is using (2), separate GECs to the UFER and the (non-required, oversized) ground rod.

You also have redundant bonding jumpers to the structural steel. But that's not and electrode or a GEC so it's not addressed by the section you cited. I know of no prohibition on redundant bonding jumpers, although perhaps objectionable current could be invoked. Might also have bad effects on the functioning of, say, audio equipment (ground loop).
Click to expand...
How about nec 2014 article 250.52(A)(2)(2)? Says hold down bolts shall be connected to UFER by welding, exothermic weld, steel ties or other approved means. Other approved mean, that might explain why bonding jumper from UFER to steel in diagram? No?
 
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jaggedben

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hhsting said:
How about nec 2014 article 250.52(A)(2)(2)? Says hold down bolts shall be connected to UFER by welding, exothermic weld, steel ties or other approved means. Other approved mean, that might explain why bonding jumper from UFER to steel in diagram? No?
Click to expand...

Okay, right, you are permitted to do that if you want to use the building steel as an electrode (which allows you to use the building steel to ground other systems throughout the building). In that case you can run the grounding electrode conductor to the building steel instead of directly to the UFER. I still do not think that you have to do both. Your picture still has redundant paths.

That is:
1) Run a GEC to the UFER for grounding, and an above-ground bonding jumper to the building steel to comply with bonding required by 250.104 (C).
or
2) Run a GEC to the building steel, and connect the hold down bolts to the UFER as you cited above.

BTW if the building is supplied by a metal water pipe then that is supposed to be used as well. Picture implies that the building doesn't have one or that whoever drew the picture is unaware of that requirement. Other than that, the picture looks to me like 'do everything that an inspector ever asked anyone to do, even if code doesn't actually require all of them.'
 
jumper

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jaggedben said:
Okay, right, you are permitted to do that if you want to use the building steel as an electrode (which allows you to use the building steel to ground other systems throughout the building). In that case you can run the grounding electrode conductor to the building steel instead of directly to the UFER. I still do not think that you have to do both. Your picture still has redundant paths.

That is:
1) Run a GEC to the UFER for grounding, and an above-ground bonding jumper to the building steel to comply with bonding required by 250.104 (C).
or
2) Run a GEC to the building steel, and connect the hold down bolts to the UFER as you cited above.

BTW if the building is supplied by a metal water pipe then that is supposed to be used as well. Picture implies that the building doesn't have one or that whoever drew the picture is unaware of that requirement. Other than that, the picture looks to me like 'do everything that an inspector ever asked anyone to do, even if code doesn't actually require all of them.'
Click to expand...

Both 1 and 2 are legal.

Good call on water pipe.

Ground rod needs to go also.
 
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hhsting

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jaggedben said:
Okay, right, you are permitted to do that if you want to use the building steel as an electrode (which allows you to use the building steel to ground other systems throughout the building). In that case you can run the grounding electrode conductor to the building steel instead of directly to the UFER. I still do not think that you have to do both. Your picture still has redundant paths.

That is:
1) Run a GEC to the UFER for grounding, and an above-ground bonding jumper to the building steel to comply with bonding required by 250.104 (C).
or
2) Run a GEC to the building steel, and connect the hold down bolts to the UFER as you cited above.

BTW if the building is supplied by a metal water pipe then that is supposed to be used as well. Picture implies that the building doesn't have one or that whoever drew the picture is unaware of that requirement. Other than that, the picture looks to me like 'do everything that an inspector ever asked anyone to do, even if code doesn't actually require all of them.'
Click to expand...
No underground water pipe or water pipe at this site. It is a structure not a building like canopy with metal frame. I cannot do 250.104(c) and 250.52(A)(2)? So I can do 250.104(c) IF 250.52(A)(2) has not been done?
 
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hhsting

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jumper said:
Too lazy to check sections.

Do either fit Jags descriptions?

How is this structure not a building?
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It has four metal legs with canopy like gas station but this is not gas station. Its open no four walls. Underneath the canopy, it has car charging stations, air stations and has H frame with panelboard mounted where incoming service is fed to the panelboard. Panelboard feeds the charging and air stations.

250.104(C) says structural frame that is interconmected to form metal building and is not intentionally grounded or bonded and likely to become energize shall be bonded.

250.52(a)(2) is aboit electrodes permitted for grounding. Says metal frame of building or structure that is connected to earth by one or more of following: (1) at least one steuctural metal member that is in dirrct contact with the earth 10 ft or more with or without concrete encasement. (2) Hold down bolts seciring the structiral steel columnthat are connected to concrete encased electrode that complies with 250.52(a)(3) and is located in the support footing or foundation.......
 
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jumper

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hhsting said:
It has four metal legs with canopy like gas station but this is not gas station. Its open no four walls. Underneath the canopy, it has car charging stations, air stations and has H frame with panelboard mounted where incoming service is fed to the panelboard.

Sent from my SM-G935U using Tapatalk
Click to expand...

So, it is building with no walls.

Assuming steel is all welded or bolted together and bolted to footer, the Jags suggestions are still valid.

Last scenario, one #4 to steel and one to CEE, no jumpers or rods. Legal.

I assume this is a 200A service.
 
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jaggedben

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hhsting said:
... I cannot do 250.104(c) and 250.52(A)(2)? So I can do 250.104(c) IF 250.52(A)(2) has not been done?
Click to expand...

If you do 250.52(A)(2) properly then you've already bonded the structural steel with the GEC and you don't have to do more work to comply with 250.104(C). Killing two birds with one stone.
 
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