Bill, there are two options.
10-208 (a) is used when the wiring method between the buildings does not
contain a bonding wire, such as triplex run overhead, and when there are no other metallic connections between the buildings (piping, other wiring systems, etc).
10-208 (b) is used when the wiring method between the buildings does
contain a bonding wire, such as TECK cable or conduit, and when there are other metallic connections between the buildings. Method B cannot be used in buildings housing livestock.
The sketches below show typical single phase installations, but would apply to three phase systems also. They are for illustrative purposes only and not intended to represent actual installations.
[This message has been edited by electric-ed (edited 12-07-2002).]