service bonding question

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stew

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federal way,washington
Heres the scenario. 200 meter base with a 2 inch rigid mast set drectly into the top right edge of the base with a locknut on the outside and a bonding bushing as the locknut on the inside. Nipple out the left hand side of the base to the panel. bonding bushing as the lock nut (and smooth surfaced fitting) on thein the meter base locknut on the outside of can. Locknut at the outside of the panel bonding bushing inside the panel with a # 4 bond. Any other bonding required? Mast is set in hole with no concentric as is the nipple.
This is an existing installation in which the panel only is being replaced.
 
RE: service bonding question

Well, stew, the simple answer is no you do not need additional bonding, however there do seem to be a few problems. First, the usual method for connecting the 2 inch rigid to the meter socket, when entering from the top is through the use of a raintight hub designed for that particular NEMA 3 enclosure. Depending on the brand of meter, this hub may also be listed as serving the purpose of bonding the conduit to ground thereby no longer necessitating the use of a grounding bushing at the socket for the conduit. The #4 ground should not be spliced between the grounding rod and the designated connection INSIDE the meter socket, taps off of this line are normal (ie. #6 for phone, cable, satelite... grounding blocks). Please note, that if your internal plumbing is metalic in origin (ie. galvanized or copper), then you must also bond your plumbing to your electrical ground within 5 feet of that pipe contacting ground (ie soil), there must also be no break in the conductive path between the bonding point and said soil. see 250.52, I am also including information from other portions of the code, as grounding and bonding is a very long section.
 
Tbones:
"Please note, that if your internal plumbing is metalic in origin (ie. galvanized or copper), then you must also bond your plumbing to your electrical ground within 5 feet of that pipe contacting ground (ie soil),"
The bonding is only required within 5 ft of the entrance if the water line meets the requirements of 250.52(A)(1), IE ten feet in contact with the soil.If not a then its not a grounding electrode, but a bonding connection must be made per 250.104 at any accessible location.
 
my inspector says I must bond the mast using the bonding bushing that is the internal locknut at this point. I was always under the impression that as long as the conduit system was continous that the service raceway only had to be bonded at one end. He says that by not using a hub(existing recessed base which does not rquire a hub) or a meyers type grounding hub or a BONDING locknut that I must therefore bond the mast. Seems ridiculous to me as each of these bonding locknuts use a set screw down into the threads to tightly connect the conduit and therefore bond the entire raceway to the can continuosly to the nipple which is bonded in the service enclosure.
I will of course submit to his request and put a bonfd in there but to make a 40 mile round trip with todays gas prices is stupid and a waste of time methinks.
 
stew said:
Heres the scenario. 200 meter base with a 2 inch rigid mast set drectly into the top right edge of the base with a locknut on the outside and a bonding bushing as the locknut on the inside. Nipple out the left hand side of the base to the panel. bonding bushing as the lock nut (and smooth surfaced fitting) on thein the meter base locknut on the outside of can. Locknut at the outside of the panel bonding bushing inside the panel with a # 4 bond. Any other bonding required? Mast is set in hole with no concentric as is the nipple.
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stew said:
This is an existing installation in which the panel only is being replaced.
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If I understand this correctly we have a conduit hitting the top of the meter with a locknut on the outside and a locknut and bond bushing on the inside. :confused:


312.2 Damp, Wet, or Hazardous (Classified) Locations
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(A) Damp and Wet Locations In damp or wet locations, surface-type enclosures within the scope of this article shall be placed or equipped so as to prevent moisture or water from entering and accumulating within the cabinet or cutout box, and shall be mounted so there is at least 6-mm ( 1/ 4-in.) airspace between the enclosure and the wall or other supporting surface. Enclosures installed in wet locations shall be weatherproof. For enclosures in wet locations, raceways or cables entering above the level of uninsulated live parts shall use fittings listed for wet locations.
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stew said:
I will of course submit to his request and put a bonfd in there but to make a 40 mile round trip with todays gas prices is stupid and a waste of time methinks.
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If I understand your post correctly and I was your inspector you would be making the trip and replacing the riser.
:rolleyes:
 
Maybe I'm reading this wrong, but did you install a bond wire?

The bonding bushing is only as good as the bond wire that bridges from the bushing and to the metal panel.
If your installing the bushing without the bond wire, the inspector is right.
 
this is a recessed instal thus no hub or sealing required. inspector is of couse correct after i reread the applicable article which is not the one he cited. anyhow maqke the trip shut up and put in the bond per code. thyx
 
how do you get a violation of that section don? the violation is section 250.90(B)the pargraph after(4) which has to do with standard locknuts not being the sole bonding means in this section for services.
 
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230.70(A)(1) Readily Accessible Location. The service disconnecting means shall be installed at a readily accessible location either outside of a building or structure or inside nearest the point of entrance of the service conductors.
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stew said:
how do you get a violation of that section don?
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Because if you installed a service disconnect inside, nearest the point of entrance of the service conductors, then it would be in the attic, from what you described. If the conduit is recessed inside the wall, where does it enter the structure?

stew said:
the violation is section 250.90(B)the pargraph after(4) which has to do with standard locknuts not being the sole bonding means in this section for services.
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You mean 250.92(B). (I'm not picking on you, I'm sparing the next guy from looking at your post and scratching his head. :D )

From what you described, you didn't rely on any standard locknuts for bonding. At what point did you? Unless you didn't install a bond wire at the bonding bushing, that would explain it. But you never clarified that.

stew said:
anyhow make the trip shut up and put in the bond per code. thyx
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Now, don't get in a hurry. Half the fun of coming here is learning the details and the whys and the way things have been installed in the past. I'd appreciate it if you'd continue to indulge us on what you saw when you showed, what you did (or didn't do), and give us the full story. At least three guys around the country aren't going to get any sleep if you drop out of this mystery before we can understand it. :)
 
. the install is as I described. recessed meter panel with the service panel adjacent to it on the inside wall. there were 2 grounding busings inside the meter base with standard locknuts on the outside of the meter base. bonding bush inside the panel bonded w/#4. bond bush set screws set to pipe and nipples but no bond wires at that point. bonding was done with the set screws only. not acceptable under 250. 92 (B) sorry for misprint. this was an old existing zinsco panel and we upgraded to sq d qo. In my opinion the set screws do the job of bonding the raceway however thats not what the code allows nor the inspector. the bond goes in, my tail goes between my legs and we move on more knowledgeble than before.
 
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So the mast actually runs inside the wall, and pops out the roof? That's wild.
baldguy.gif
 
georgestolz said:
So the mast actually runs inside the wall, and pops out the roof? That's wild.
baldguy.gif
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George I don't know Stew's location but that kind of service is common in CA.

Here I would be laughed at by the inspectors.
 
Here I would be laughed at by the inspectors.
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Same thing here. Outside of the building means on the outside in this neck of the woods. Only real exception is a mast extending through the eave.
 
Well, if it's existing, the inspector wouldn't have much to say about it, would he/she?

Unless, perhaps, the panel in question contains the service disconnect.

All things being equal, the inspector might have been walking a fine line requiring the mast to be properly bonded. An understandable, justifiable line, but a legally questionable one. :)
 
Stew,
how do you get a violation of that section don?
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The service conductors are inside of the wall and therefore inside of the building. That is a code violation and in my mind a serious one. There is not overcurrent protection for these conductors and any fault on the line side of the service OCPD will very likely result in a fire.
Don
 
why is it a code violation. whats the difference if I have a 15 foot rigid pipe bringing the service conductors to the panel which is legal in our state? and the panel service disconnect inside the house? of course it is like any other interior service disconnect. I fail to see any violation or danger here at all.
 
why is it a code violation. whats the difference if I have a 15 foot rigid pipe bringing the service conductors to the panel which is legal in our state?
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It appears that your state has set a number to "nearest the point of entrance". However, I would include the service riser in the 15'. I have seen what happens to even rigid conduit with a fault on the line side of the service OCPD. It provides very little protection from fire. It is my opinion (a very minority opinion) that the words "nearest the point of entrance" mean exactly that. The service disconnect must be on the inside of the wall where the conductors enter the building. No allowance of any lenght. If it was up to me, the service OCPD would be required to be on the outside of the structure.
Don
 
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