Power to a farm

[trojans4]

Question on electric supplied to a farm. Single phase 120/240 power comes overhead from the power company transformer to a pole in the farm yard down to the meter and back up the pole where it goes overhead to several farm buildings and the house. There is a disconnect on the pole that would shut off all power to all buildings including the house. There is no overcurrent protection on the pole. There is only one breaker panel in the house. Question 1) Does the disconnect on the pole make the house breaker panel a subpanel where the neutral and equipment ground bus bars have to be isolated? I say no but the guy building the house says yes. Question 2) Why do you need 4 wire from the pole to the main breaker in the house? If the power came directly to a meter on the house from the transformer it would just be 3 wire, 2 hots and a neutral. I am just doing the inside wiring so only question 1 affects me as far as whether to bond the neutral and equipment ground at the breaker panel.

 

[LarryFine]

Question 1) Does the disconnect on the pole make the house breaker panel a subpanel where the neutral and equipment ground bus bars have to be isolated? I say no but the guy building the house says yes.

Depends. '05 and before, no, unless there's an interconnecting metallic pathway between the pole and the house (other than the neutral); '08 and later NEC, yes.

In either case, the feeder entrance to the house requires a main disconnect (or the 6-handle limit rule.)

Question 2) Why do you need 4 wire from the pole to the main breaker in the house? If the power came directly to a meter on the house from the transformer it would just be 3 wire, 2 hots and a neutral.

Yes, but, if there was a disco on the outside of the house, a 4-wire feeder would be required. The meter is looked at as a 'lump in the service cabling.'

 

[augie47]

This very well may be looked at in different depending on your jurisdiction.
Most often here the switch at the pole would not be considered a service disconnect due to the lack of OCP (integral or adjacent per 230.91) and the services to the buildings would be 3 wire.

 

[realolman]

That's what I think. If it had OCP , then you would have a sub feed... without it ... not.

That's the point where most people put a generator transfer switch

 

[iwire]

I agree with Gus, this could really depend on the areas standard practices. You should talk to that areas inspector.

 

[kwired]

I agree with others in that it may depend on an areas practices.

It may also depend on if the equipment on the pole is POCO owned equipment or customer owned equiipment.

No overcurrent device at pole means everything on the load side of the pole is still service equipment. There would be no violation if separate grounded and grounding conductors but may not be required.