ground lugs in transformer
- Thread starter sparky56
- Start date
- Status
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Re: ground lugs in transformer
Seperate Lugs would mean that the steel of the enclosure is serving as part of the ground path.
Seperate Lugs would mean that the steel of the enclosure is serving as part of the ground path.
paul
Senior Member
- Location
- Snohomish, WA
Re: ground lugs in transformer
Did he quote you a code article that says it's a violation?
Did he quote you a code article that says it's a violation?
- Location
- Massachusetts
Re: ground lugs in transformer
Personally I simply order 3 barrel lugs for this purpose, it's easer and perhaps just a little better connection. By the way I hope your cleaning the paint off the metal where you are bolting the lugs on.
I also use three barrel lugs on the XO.
The XO should have the GEC, bonding jumper and the derived neutral all connected directly to it.
Nothing unusual or against code about that.
Personally I simply order 3 barrel lugs for this purpose, it's easer and perhaps just a little better connection. By the way I hope your cleaning the paint off the metal where you are bolting the lugs on.
I also use three barrel lugs on the XO.
The XO should have the GEC, bonding jumper and the derived neutral all connected directly to it.
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
Re: ground lugs in transformer
Since the GEC and the bonding jumper are the same size couldn't the GEC be used as both? I've seen the GEC connected to a lay in style lug bonded to the metal enclosure and then continuing unbroken to the Xo.
Bob,
Since the GEC and the bonding jumper are the same size couldn't the GEC be used as both? I've seen the GEC connected to a lay in style lug bonded to the metal enclosure and then continuing unbroken to the Xo.
- Location
- Massachusetts
Re: ground lugs in transformer
The GEC and the bonding jumper are not necessarily the same size for an SDS, often the bonding jumper is larger.
I have never seen that but it sounds good as long as the size is correct.
The GEC and the bonding jumper are not necessarily the same size for an SDS, often the bonding jumper is larger.
sandsnow
Senior Member
- Location
- Southern California
Re: ground lugs in transformer
Based on last sentence of 250.30(A)(2)(a) which sends us to 250.24(A)(4); if the GEC does not terminate at XO, I ask for a double lug mounted to the enclosure or two lugs under one bolt.
edit add: Also the last sentance of 250.30(A)(1) requires the bonding jumper to connect to the same point as the GEC.
As far as the equip grds, 250.130 sends us to 250.30(A)(1). There the code tells us to connect the equip grd conductors to the grounded cond. with the bonding jumper. I think this is where the inspector is getting the one bolt interpretation.
How the bonding jumper connects the equip grd cond's is not really clear to me.
Can anyone help me see what I might be missing here? 250.24(A)(4) would suggest the the intent is a equip grd terminal bar.
I have asked for the double lug set up in my first paragraph and allowed equip grd cond's to connect to the bonding jumper via the enclosure. Paint scraped of course and full metal to metal contact, meaning not using the vent openings for holes for the bolts.
Perhaps 408.20 should be extended to all enclosures and equipment where grounding conductors are provided? If that is what the code has in mind.
[ October 07, 2005, 12:04 PM: Message edited by: sandsnow ]
Based on last sentence of 250.30(A)(2)(a) which sends us to 250.24(A)(4); if the GEC does not terminate at XO, I ask for a double lug mounted to the enclosure or two lugs under one bolt.
edit add: Also the last sentance of 250.30(A)(1) requires the bonding jumper to connect to the same point as the GEC.
As far as the equip grds, 250.130 sends us to 250.30(A)(1). There the code tells us to connect the equip grd conductors to the grounded cond. with the bonding jumper. I think this is where the inspector is getting the one bolt interpretation.
How the bonding jumper connects the equip grd cond's is not really clear to me.
Can anyone help me see what I might be missing here? 250.24(A)(4) would suggest the the intent is a equip grd terminal bar.
I have asked for the double lug set up in my first paragraph and allowed equip grd cond's to connect to the bonding jumper via the enclosure. Paint scraped of course and full metal to metal contact, meaning not using the vent openings for holes for the bolts.
Perhaps 408.20 should be extended to all enclosures and equipment where grounding conductors are provided? If that is what the code has in mind.
[ October 07, 2005, 12:04 PM: Message edited by: sandsnow ]
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