WE HAVE TWO DORMITORY'S, DORM 1 AND DORM 2. DORM 1 HAS A 480/277 VOLT SERVICE. THIS SERVICE WILL FEED DORM 2 THROUGH A 1600 AMP BREAKER. DORM 2 IS NEXT DOOR TO DORM 1 OWNWED BY SAME UNIVERSITY. DORM 2 IS FED BY PVC UNDERGROUNG CONDUITS,AND THERE IS NO METALLIC OR STEEL CONNECTION BETWEEN THESE BUILDINGS. THIS FEED WILL TERMINATE RIGHT TO THE MAIN BUSS IN DORM 2,NO MAIN DISCONNECT. THE DISCONNECT IS IN DORM 1. MY QUESTION IS DO I NEED TO PULL GROUNDING WIRES WITH MY FEEDERS OR CAN I TREAT THE FEEDER AS A NEW SERVICE AT DORM 2. THANK YOU
ONE BUILDING FED FROM ANOTHER BUILDING ON SAME PREMESIS
- Thread starter timz
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charlie
Senior Member
- Location
- Indianapolis
Re: ONE BUILDING FED FROM ANOTHER BUILDING ON SAME PREMESIS
Sorry, I have a tough time believing that there will be no metallic paths now or any time in the future between these two buildings (although you can't control the future and the Code is not written for the possibilities). No metal piping systems, metallic shields on communications cables, not so much as a gas line? My personal preference is that you pull a grounding conductor.
If all that is true and you can live with it, the Code doesn't prohibit the installation. Don't overlook the question that Bennie has asked.
Sorry, I have a tough time believing that there will be no metallic paths now or any time in the future between these two buildings (although you can't control the future and the Code is not written for the possibilities). No metal piping systems, metallic shields on communications cables, not so much as a gas line? My personal preference is that you pull a grounding conductor.
If all that is true and you can live with it, the Code doesn't prohibit the installation. Don't overlook the question that Bennie has asked.
Re: ONE BUILDING FED FROM ANOTHER BUILDING ON SAME PREMESIS
I have got to go with Bennie and Charlie suspicions. To CYA, I would run a grounding conductor. No matter what you will be covered. In addition, I would establish a ground electrode at Dorm two, just for lightning safety.
I have got to go with Bennie and Charlie suspicions. To CYA, I would run a grounding conductor. No matter what you will be covered. In addition, I would establish a ground electrode at Dorm two, just for lightning safety.
- Location
- Bremerton, Washington
Re: ONE BUILDING FED FROM ANOTHER BUILDING ON SAME PREMESIS
Preferred method is not to reground the neutral at the second building. In fact, Washington State will no longer allow seperate buildings or structures to have the neutral to be regrounded after Aug 1, 2003. Mike Holts 2002 Grounding and Bonding text has an excellent review of the objectionable current your proposed method may create.
Your seperate building (dorm) requires a main disconnect.
Also the second building will require a grounding electrode system per 250.30.
Preferred method is not to reground the neutral at the second building. In fact, Washington State will no longer allow seperate buildings or structures to have the neutral to be regrounded after Aug 1, 2003. Mike Holts 2002 Grounding and Bonding text has an excellent review of the objectionable current your proposed method may create.
Your seperate building (dorm) requires a main disconnect.
Also the second building will require a grounding electrode system per 250.30.
Re: ONE BUILDING FED FROM ANOTHER BUILDING ON SAME PREMESIS
Provided you qualify for one of the exceptions to 225.32 (as eprice has stated) then 250.32(D) would apply. It does not give you a choice. You have to pull an EGC and you cannot connect the grounded conductor to the second buildings grounding electrode system.
Hi Bennie! Glad to see you again.
[ March 10, 2003, 09:48 PM: Message edited by: Nick ]
Provided you qualify for one of the exceptions to 225.32 (as eprice has stated) then 250.32(D) would apply. It does not give you a choice. You have to pull an EGC and you cannot connect the grounded conductor to the second buildings grounding electrode system.
Hi Bennie! Glad to see you again.
[ March 10, 2003, 09:48 PM: Message edited by: Nick ]
Re: ONE BUILDING FED FROM ANOTHER BUILDING ON SAME PREMESIS
BENNIE, SORRY ABOUT THE INFO. THERE MAY BE A WALKWAY BETWEEN THE BUILDINGS BUT THE GENERAL IS NOT CERTAIN AT THIS TIME. THERE WILL BE A MAIN DISCONNECT IN DORM 1 FOR DORM 2 AT THE COMMON SERVICE . I ALSO AGREE WITH EVERYONE THAT GROUNDING CONDUCTORS SHOULD BE PULLED AS NOTED IN SEC 250.32{D} PER 2002 NEC, BUT I'M OVER RULED BY FOREMAN ON JOB.
BENNIE, SORRY ABOUT THE INFO. THERE MAY BE A WALKWAY BETWEEN THE BUILDINGS BUT THE GENERAL IS NOT CERTAIN AT THIS TIME. THERE WILL BE A MAIN DISCONNECT IN DORM 1 FOR DORM 2 AT THE COMMON SERVICE . I ALSO AGREE WITH EVERYONE THAT GROUNDING CONDUCTORS SHOULD BE PULLED AS NOTED IN SEC 250.32{D} PER 2002 NEC, BUT I'M OVER RULED BY FOREMAN ON JOB.
- Location
- Bremerton, Washington
Re: ONE BUILDING FED FROM ANOTHER BUILDING ON SAME PREMESIS
What about the AHJ?
Ask the foreman why building 2 does not have a main disconnect per Art 225?
What about the AHJ?
Ask the foreman why building 2 does not have a main disconnect per Art 225?
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: ONE BUILDING FED FROM ANOTHER BUILDING ON SAME PREMESIS
unless this panel has less than 6 breakers?
I dont think so.
unless this panel has less than 6 breakers?
I dont think so.
Re: ONE BUILDING FED FROM ANOTHER BUILDING ON SAME PREMESIS
Unless the data cables and telephone cables for these dorms are fiber optic you had better pull an EGC. If you don't you may find neutral current travelling on the telephone cables and the campus local area network and that will get reeal expensive. You may find yourself at the head of the line when the customer starts looking for someone to blame.
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Tom
Unless the data cables and telephone cables for these dorms are fiber optic you had better pull an EGC. If you don't you may find neutral current travelling on the telephone cables and the campus local area network and that will get reeal expensive. You may find yourself at the head of the line when the customer starts looking for someone to blame.
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Tom
stars13bars2
Senior Member
Re: ONE BUILDING FED FROM ANOTHER BUILDING ON SAME PREMESIS
timz
What happened to the approved plans with the engineers stamp that shows the required the main disconnect? This was not a design build project was it?
stars
timz
What happened to the approved plans with the engineers stamp that shows the required the main disconnect? This was not a design build project was it?
stars
Re: ONE BUILDING FED FROM ANOTHER BUILDING ON SAME PREMESIS
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Tom
The tip conductor of each pair is grounded at the exchange but that is not the issue. The copper sheild of underground telephone cable is bonded to the building grounding electrode system at the network protectors in each building. The messenger of overhead multi pair cable is also bonded at the protectors. The lower impedance of the grounded conductor will not save you from some parrallel neutral current flow over the unintended pathway. The presence of stray AC current on that telephone cable sheild or messenger plays hell with signal quality. If the neutral between the two buildings ever fails that shield or messenger would carry substantial current which may cause it to fail and energise the individual pair conductors.
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Tom
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