Bonding a system twice question.

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qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Engineering
Recently I have run across several buildings that were bonded inside in the main disconnect or panel and also in the service disconnect at the exterior pedestal.
My question is: Just how dangerous is this? And is not bonding at all more dangerous than
bonding twice?
I am wondering what is the best thing for us to do. Bond it and tag it clearly as bonded or
not bond it and tag it clearly as not bonded?
I know we can't control what the EC installing the service does and from what I've seen
on some of the sites I've been to they don't fully understand bonding a service at all.
Thanks for your opinions.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
Prior to 2008 it was code compliant if there was a 3 wire cable & there wasn't any metallic pathways ( phone, copper water lines, etc) between the pedestal & the building.
 

iwire

Moderator
Staff member
Location
Massachusetts
Very common to have it bonded at the metering equipment and at the service disconnecting mean, virtually all services are set up like that.

Is the switch at the building the service disconnect or the one at the pedestal?

The one at the pedestal could be a meter disconnect.

See 250.142(A)
 

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Engineering
Very common to have it bonded at the metering equipment and at the service disconnecting mean, virtually all services are set up like that.

Is the switch at the building the service disconnect or the one at the pedestal?

The one at the pedestal could be a meter disconnect.

See 250.142(A)
"Is the switch at the building the service disconnect or the one at the pedestal?"

The switch at the pedestal is the service disconnect.

"The one at the pedestal could be a meter disconnect."

Nope. From the meter to the service disconnect to the disconnect in our building.
It's bonded in the service disconnect and the disconnect in our building. The bond in our building was not removed.

"Very common to have it bonded at the metering equipment and at the service disconnecting mean, virtually all services are set up like that."

Agreed. So it could be bonded in 3 places. I didn't think pulling the meter to look would win me a lot of friends at the POCO.
 

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Engineering
Originally Posted by Dennis Alwon
how many conductors are in the pvc?

Brian John: All of them?

Yep! All of them! LMAO!
2 hots, a neutral and the equipment ground.
 

ceb58

Senior Member
Location
Raeford, NC
If I may let me help Mike out. This is a problem he and I have been discussing. Mike works for the company that makes the communication buildings we buy. When they build a building they install the service disconnect inside with just a nipple going to the outside. They install the bonding screw in the disconnect because they do not know if it will just be a meter base installed or an outside disconnect.
Now after the building is set up the contract elect. installs a meter/disconnect combo on the outside of the building (GEC bonded in meter combo). No pedestal involved. From the meter combo they are running 4 wires ( 2 ungrounded 1 grounded and 1 EGC) to the inside disconnect. This is where they are NOT removing the bonding screw. As I see it it is a violation of 250.32. We have had several lightning strikes that has damaged equipment. In every one that has had sever damage is the ones that the inside bonding screw is still installed. The screw in some cases have burned so bad that it is welded to the can. May be this helps explain the situation so we can get answers to Mike's question.

My question is: Just how dangerous is this? And is not bonding at all more dangerous than
bonding twice?
I am wondering what is the best thing for us to do. Bond it and tag it clearly as bonded or
not bond it and tag it clearly as not bonded?
I know we can't control what the EC installing the service does and from what I've seen
on some of the sites I've been to they don't fully understand bonding a service at all.
Thanks for your opinions.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
Originally Posted by Dennis Alwon
how many conductors are in the pvc?

Brian John: All of them?

Yep! All of them! LMAO!
2 hots, a neutral and the equipment ground.
If this is the case then the neutral an EGC do not get bonded together at the building. The GEC get connected to the ground bar not the neutral bar.
 

ActionDave

Moderator
Staff member
Location
Durango, CO, 10 h 20 min without traffic from wing
Occupation
wire pulling grunt
Recently I have run across several buildings that were bonded inside in the main disconnect or panel and also in the service disconnect at the exterior pedestal.
My question is: Just how dangerous is this? And is not bonding at all more dangerous than
bonding twice?
I am wondering what is the best thing for us to do. Bond it and tag it clearly as bonded or
not bond it and tag it clearly as not bonded?
I know we can't control what the EC installing the service does and from what I've seen
on some of the sites I've been to they don't fully understand bonding a service at all.
Thanks for your opinions.
I would opt for not bonding and tag as such.

As an electrician you most always bond at the meter/service disco. As an apprentice you ask ,"Why?" and you are told, "Because that's where the inspector wants it."
That pretty much sums up your instruction in grounding and bonding.

A lot of guys are gonna bond on the outside and likely be reluctant change what you did at the factory.
 

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Engineering
If I may let me help Mike out. This is a problem he and I have been discussing. Mike works for the company that makes the communication buildings we buy. When they build a building they install the service disconnect inside with just a nipple going to the outside. They install the bonding screw in the disconnect because they do not know if it will just be a meter base installed or an outside disconnect.
Now after the building is set up the contract elect. installs a meter/disconnect combo on the outside of the building (GEC bonded in meter combo). No pedestal involved. From the meter combo they are running 4 wires ( 2 ungrounded 1 grounded and 1 EGC) to the inside disconnect. This is where they are NOT removing the bonding screw. As I see it it is a violation of 250.32. We have had several lightning strikes that has damaged equipment. In every one that has had sever damage is the ones that the inside bonding screw is still installed. The screw in some cases have burned so bad that it is welded to the can. May be this helps explain the situation so we can get answers to Mike's question.
Thanks Ceb for clarifying my question.



My question is: Just how dangerous is this? And is not bonding at all more dangerous than
bonding twice?
I am wondering what is the best thing for us to do. Bond it and tag it clearly as bonded or
not bond it and tag it clearly as not bonded?
I know we can't control what the EC installing the service does and from what I've seen
on some of the sites I've been to they don't fully understand bonding a service at all.
Thanks for your opinions.
 

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Engineering
I would opt for not bonding and tag as such.

As an electrician you most always bond at the meter/service disco. As an apprentice you ask ,"Why?" and you are told, "Because that's where the inspector wants it."
That pretty much sums up your instruction in grounding and bonding.

A lot of guys are gonna bond on the outside and likely be reluctant to change what you did at the factory.
That was pretty much my training on bonding also, until I took some classes on grounding and bonding and studied the code.
Also, I agree with you on being reluctant to remove what we installed.
 

ceb58

Senior Member
Location
Raeford, NC
Thanks Ceb for clarifying my question.



My question is: Just how dangerous is this? And is not bonding at all more dangerous than
bonding twice?
I am wondering what is the best thing for us to do. Bond it and tag it clearly as bonded or
not bond it and tag it clearly as not bonded?
I know we can't control what the EC installing the service does and from what I've seen
on some of the sites I've been to they don't fully understand bonding a service at all.
Thanks for your opinions.
Your welcome
 

pete m.

Senior Member
Location
Ohio
My question is: Just how dangerous is this? And is not bonding at all more dangerous than
bonding twice?
I am wondering what is the best thing for us to do. Bond it and tag it clearly as bonded or
not bond it and tag it clearly as not bonded?
I know we can't control what the EC installing the service does and from what I've seen
on some of the sites I've been to they don't fully understand bonding a service at all.
Thanks for your opinions.
The "hazard" as I see it would be that with bonding the grounded conductor at the service disconnect and at the feeder disconnect it would allow current to flow on a grounding conductor. A violation of 250.6

Pete
 

ceb58

Senior Member
Location
Raeford, NC
I would opt for not bonding and tag as such.

A lot of guys are gonna bond on the outside and likely be reluctant change what you did at the factory.
I agree, but I would because it is adding to my work load:)
I also think the problem is as Dave said. They see (maybe) the screw that is installed at the plant. And because the building is inspected and tagged as such they wont remove the screw.
 
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