subpanel

[enireh]

working on large acreage property with many sub panels does each sub panel need a ground also or just two hots and a ground feed (three wire feed) or do I need to run four wires? two hots, a neutral and a ground?

 

[augie47]

I don't recall which Code cycle for sure but I think it was the 2005 that made an equipment grounding conductor mandatory for runs to separate buildings.
Prior to that there were some instances where the grounded conductor could be used for grounding on runs to separate buildings.

 

[GoldDigger]

working on large acreage property with many sub panels does each sub panel need a ground also or just two hots and a ground feed (three wire feed) or do I need to run four wires? two hots, a neutral and a ground?

It depends on where the subpanels are located.
Each separate building in the system will need its own local ground electrode(s) in addition to the EGC from the main distribution. If all of the load on the subpanel does not use the neutral, you can leave it out of the feeder, but there must always be an EGC and there must also be a local electrode for each building. Multiple subpanels within one building can share the same local ground electrode(s).

 

[jxofaltrds]

I don't recall which Code cycle for sure but I think it was the 2005 that made an equipment grounding conductor mandatory for runs to separate buildings.
Prior to that there were some instances where the grounded conductor could be used for grounding on runs to separate buildings.

2008 NEC

That said - Paralleled 'conductors' change everything.

Opinion: If I lived in the country and had multiple buildings, no paralleled paths, I would use a 3-wire all day long. But since we are talking code; as stated before - what code cycle are you using?

 

[enireh]

sub panel

sub panel

working on large acreage property with many sub panels does each sub panel need a ground also or just two hots and a ground feed (three wire feed) or do I need to run four wires? two hots, a neutral and a ground?

so what about driving a ground rod at each sub panel?

 

[John120/240]

so what about driving a ground rod at each sub panel?

Drive one & run 4 wire to each sub panel. Each separate structure requires a GES (Grounding Electrode System). As goldigger said For multiple sub panels in one structure/building their will be one GES for the building & all sub panels will tie into one GES

 

[Dennis Alwon]

At a separate structure we run 4 wires and drive 2 rods. The rods are connected to the equipment grounding conductor of the 4 wire feeder. The neutrals and equipment grounding conductor are separated just like any other subpanel.