What am I missing

Status
Not open for further replies.
ceb58

ceb58

Senior Member
Location
Raeford, NC
Here is the scenario I am involved with. I am doing the gen. wiring on a building for a ball field. An out of state contractor is doing the lighting for the ball fields. Here is their set up. 480v 3 phase Panel with 600 amp main breaker. In this panel there are 14 30amp 3 pole breakers, on the top of the buss there are feed thru lugs which feeds another 600amp rated main lug panel with 11 30amp 3 pole breakers. Here is where it is a head scratcher. The contractor has pulled 3 500mcm's to the poco pad mount transformer 320' away. By 310.16 500mcm in the 75deg. coll. rates it for 380amps.:confused:
I do not know the draw for the lighting but the 24 30 amp breakers feed 24 poles with 5 lights each. and one breaker feeds a 480/208-120 30 kw transformer.
I know it's not my install but what am I missing with the sizing of the service conductors?
 
masterinbama said:
by the POCO or the contractor. Our local POCO pulls based on calculated load and not overcurrent rating.
Click to expand...

The contractor pulled to the transformer. More of the story. This ball field is being built for the county. The county maint. dept installed 2 4" cond. and 1 2". The 2 4'' were for power and the 2" for phone. They needed to get the pipe in the ground as to not hold up the contractor that was landscaping the fields. Normally we ( elect. cont.) do not pull any thing past the meter base, poco handles wiring to meter base. This building will have two services, the 480 3 phase will be metered at the transformer for the lighting, my 240/120 1 phase for the building will be metered on the building.
 
It does not matter who actually "pulled" the conductors. What is important is, who "controls" the conductors.

If these conductors are under the control of the utility, on their side of the service point, they are subject to the NEC. If these conductors are after the service point, they need to be sized (and protected) based on the NEC.
 
jim dungar said:
It does not matter who actually "pulled" the conductors. What is important is, who "controls" the conductors.

If these conductors are under the control of the utility, on their side of the service point, they are subject to the NEC. If these conductors are after the service point, they need to be sized (and protected) based on the NEC.
Click to expand...
So according to you they are under the NEC no matter what. But what about the fact that the power company has their own guidelines and isn't under the NEC?
 
jim dungar said:
It does not matter who actually "pulled" the conductors. What is important is, who "controls" the conductors.

If these conductors are under the control of the utility, on their side of the service point, they are subject to the NEC. If these conductors are after the service point, they need to be sized (and protected) based on the NEC.
Click to expand...

With that said Jim, the wire would be on the customer side since the poco will meter these from the pad mount transformer.
I think you meant to say they are not subject to NEC if on utility side.
 
jim dungar said:
It does not matter who actually "pulled" the conductors. What is important is, who "controls" the conductors.

If these conductors are under the control of the utility, on their side of the service point, they are subject to the NEC. If these conductors are after the service point, they need to be sized (and protected) based on the NEC.
Click to expand...

OOPS,

Utility side NOT subject to NEC.
 
Status
Not open for further replies.
Top