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12-11-2008, 10:02 PM
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#1
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Junior Member
Join Date: Dec 2008
Location: Texas
Posts: 3
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Branch circuit conversion - grounded conductor?
We have an existing 227/480v 75amp circuit servicing a 20 ton chiller (no grounded conductor). Our client wants to demo the chiller and convert the existing circuit to a feeder to power a sub panel. This new panel will only power 3 motors (5 hp each, 480v 3 phase). Does the NEC require that we pull in a grounded conductor to comply? And where in the code is this located?
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12-11-2008, 10:35 PM
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#2
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Senior Member
Join Date: Jan 2007
Location: Baltimore, MD, USA
Posts: 3,527
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Quote:
Originally Posted by Batas
We have an existing 227/480v 75amp circuit servicing a 20 ton chiller (no grounded conductor). ....
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So is it 480v (no grounded conductor, or 480/277 (which DOES imply a grounded conductor)
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John from Baltimore
"One day at a Time"
All responses based on the '08 NEC
It's not my fault, it's not my problem, I'm not your solution. 
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12-11-2008, 11:33 PM
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#3
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Junior Member
Join Date: Dec 2008
Location: Texas
Posts: 3
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The existing branch circuit supplying the 20 ton chiller does not have a grounded conductor. . . .
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12-11-2008, 11:42 PM
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#4
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Burger Flipper
Join Date: Aug 2007
Location: Bay Area, CA
Posts: 2,363
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Neutral is not required to be present if you do not have any loads requiring it to be there.
~Matt
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12-12-2008, 05:40 AM
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#5
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Senior Member
Join Date: Apr 2008
Location: Maine - Al Asad, Iraq (for now)
Posts: 397
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Quote:
Originally Posted by Batas
The existing branch circuit supplying the 20 ton chiller does not have a grounded conductor. . . .
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Does it have an equipment grounding conductor?
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Rick Boudreau
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Al Asad, Iraq
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12-12-2008, 09:40 AM
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#6
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Junior Member
Join Date: Dec 2008
Location: Texas
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Yes. . . .
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12-12-2008, 09:51 AM
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#7
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Not Banned Yet
Join Date: Dec 2007
Location: Not there yet!
Posts: 1,141
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Is there an echo in here?
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12-12-2008, 10:42 AM
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#8
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Senior Member
Join Date: Apr 2008
Location: Maine - Al Asad, Iraq (for now)
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Quote:
Originally Posted by BryanMD
Is there an echo in here?
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I was asking about the equipment grounding conductor not the grounded condcutor that it was already stated is not present. The equipment grounding conductor was not mentioned prior to my post. 
If the equipment grounding conductor is present, and the GROUNDED conductor is not needed there is no reason to install it.
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Rick Boudreau
TASK FORCE SAFE INSPECTION TEAM LEADER
Al Asad, Iraq
"fool-proof systems do not take into account the ingenuity of fools"
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12-24-2008, 12:19 PM
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#9
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Junior Member
Join Date: Dec 2008
Location: Michigan
Posts: 3
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480/277
If the equiment is 480/277 then you should have all the conductors you need plus one extra (3phase, 1grounded, 1ground), if you have a 480V connection you would still have 3phase conductors plus a ground so you should have the applicable wiring avaliable, another item not knowing the in's and out's of the installation what about bonding the conduit (if not already done so) provide a bonding bushing at each end and use th conduit as a ground path?
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11-09-2009, 03:31 AM
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#10
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Junior Member
Join Date: Nov 2009
Location: philippines
Posts: 1
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Quote:
Originally Posted by TheRick
I was asking about the equipment grounding conductor not the grounded condcutor that it was already stated is not present. The equipment grounding conductor was not mentioned prior to my post.
If the equipment grounding conductor is present, and the GROUNDED conductor is not needed there is no reason to install it. |
yah i agree w/you
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11-09-2009, 06:16 AM
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#11
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Senior Member
Join Date: Feb 2009
Location: us
Posts: 1,312
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Quote:
Originally Posted by mike01
If the equiment is 480/277 then you should have all the conductors you need plus one extra (3phase, 1grounded, 1ground), if you have a 480V connection you would still have 3phase conductors plus a ground so you should have the applicable wiring avaliable, another item not knowing the in's and out's of the installation what about bonding the conduit (if not already done so) provide a bonding bushing at each end and use th conduit as a ground path?
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The bonding bushing is not required unless you're going into eccentric KO's. You can't have 277 without a grounded conductor. But if your loads do not require it, you do not have to run it.
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11-09-2009, 06:25 PM
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#12
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Chairman of the Bored
Join Date: Oct 2008
Location: Atlanta, Ga.
Posts: 4,789
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Quote:
Originally Posted by angelito
yah i agree w/you
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I beat Billy to this one:
Welcome to forum.
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11-09-2009, 06:47 PM
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#13
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Licensed Journeyman
Join Date: Oct 2007
Location: third world
Posts: 1,743
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Quote:
Originally Posted by angelito
yah i agree w/you
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welcome to the forum 
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