"Doug Miller" wrote in message
...
In article
,
stryped wrote:

What I dont understand is why the need to separate the neutral bus and
ground as they all end up combined in the main panel anyway.

Because the neutral conductor _carries_current_. If you combine neutral
and
ground anywhere except in the main panel, then all of your ground
conductors
*everywhere* are carrying current also.

Not everywhere, because there should be no cause for current to flow on
equipment grounding conductors connected to equipment in good condition.
Specifically on the feeder to the subpanel. The grounding conductor would be
paralleled with the grounded conductor (sharing the neutral load), and could
be an unsafe situation particularly if the grounding conductor is metallic
conduit, and especially if the neutral is impaired by poor connections,
etc..