[bertfisher]

I have a 200 amp meter on a power company pole in the country for barn electricity. I have built a small shed 285' away and want 100 amp service. Based on the distance, I am planning on using 4/0 4/0 2/0 Al URD cable in 2" conduit buried 24". To get the lug sizes to fit the 4/0, I am using 200 amp breakers and load centers.

On the electrical pole, just below the meter, I plan to have a 200 amp circuit breaker, then go through the conduit to the shed, where I will have a 200 amp Main Lug Center. I plan to keep the equipment ground separate from neutral all the way back to the circuit breaker panel on the power pole, where I will bond them.

My questions are:

1. If I bond the neutral and equipment ground at the circuit breaker on the power pole as described above, what Cu wire size for equipment ground would you recommend based on the distance of 285'?

2. Can the equipment ground wire be run bare in the same conduit with the 4/0 4/0 2/0 URD cable, or should the ground wire be jacketed?

3. As an alternate, to save money on the Cu equipment ground wire, can I eliminate the 285' of ground wire altogether by adding a second circuit breaker at the panel at the shed (I want to keep the breaker at the power pole to protect the 285' of buried cable) and bonding the neutral and equipment ground at the shed panel, and having two 8' brass ground rods at the shed? In other words, with grounding and bonding at the breaker panel at the shed, does the application still need to have an equipment ground wire running back to the breaker panel on the power pole?

Thank you!

[tkrussell]

Grounding the grounded conductor must begin at the first means of disconnect. It is at this point the equipment grounding begins and is separated from the grounded conductor (neutral).

You can either eliminate the Main Disconnect at the pole, (which I understand you want to use) or use 4 wire URD cable from the disconnect at the pole to the panelboard in the shed.

Having a second main disconnect at the panel is not required and offers nothing but convenience.

If you already own the 3 wire URD, then add a #4 copper bare or insulate or # 2 aluminum insulated next to the cable.

Drive at least one 8 foot ground rod (two is better, and may be required in your area)and connect it to the neutral bar at the main disconnect. The neutral bar at the main will have the input neutral, output neutral, the grounding electrode conductor from the rod, and must also connect to the metal box using a screw driven through the bar into a machine threaded hole, or use a small jumper wire.

At the panel, the neutral bar must be kept insulated from the metal box and any equipment grounds. The equipment ground bar and any equipment grounding conductors all connect directly to this bar, which is bolted directly to the metal box using machine thread screws and threaded holes.

[Diedre]

Does no 6 grounding wire 200 amp service have to be insulated or can it be bare going from ground rod to the panel

[tkrussell]

Yes it can be bare.

Remember, #6 can only be used if going to a ground rod(s).