If you are feeding a subpanel(50-125 amp) from a main service panel(200 amp) , do you need to have 4 wires to the sub panel?
The grounding and grounded conductors are terminated at same place (theoretically) in the sub panel...
No. They are in the disconnect or main load center, whichever is first in line from the meterbase.
therefore you would need to use the supplied "bonding" screw (green).right?
No, not it the sub-panel, but in the first panel in line from the meterbase.
Note: You will need to aquire an equipment ground bus bar for your sub-panel.
Also note: You also must size the sub-feeder conductors according to Table 310.16, for 310.15(B)(6) is for "...conductors that serve as the main power feeder to a dwelling..."
[This message has been edited by sparky66wv (edited 09-16-2002).]