Branch circuit conversion - grounded conductor?

Status
Not open for further replies.
B

Batas

New member
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?
 
Batas said:
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?
Click to expand...

I believe you do NOT have to pull a grounded conductor to a sub if the loads do not require a grounded conductor.

~Matt
 
It's alright. Many subpanels are fed this way when they have zero neutral load. Often times, we bring the grounded conductor to the service disconnect as required and stop it there.
 
If the old equipment has 277/480, then there's already a grounded conductor present. Otherwise, there would be no 277 available.
 
Batas,

You have a 480v 3 ph feeder right now, you can use it for a 480v 3ph panel. On a system

with 480/277v the grounded conductor is only 'required' to the service disconnecting means

, of course, at any panel in need of 277v.
 
not grounded, but EGC..........

not grounded, but EGC..........

OSHA does have this rule if it applies in your case..........

1910.304(g)(8)(iii)
For installations made before April 16, 1981, electric equipment is also considered to be effectively grounded if it is secured to, and in metallic contact with, the grounded structural metal frame of a building. When any element of this branch circuit is replaced, the entire branch circuit shall use an equipment grounding conductor that complies with all other provisions of paragraph (g) of this section.
 
Bill, the OP seems to be asking about a neutral conductor, and unless this was a service, it is not needed if there are no loads that would require it.

Roger
 
Batas said:
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?
Click to expand...
As stated there is no requirement to pull the grounded circuit conduct past the service equipment.
 
Status
Not open for further replies.
Top