Replies

1. 
   pm22 | May 19, 2004 07:34am | #1

   Maybe you should've asked this question of Mr. Popejoy.

   The temporary box must be grounded.

   The theory behind connecting the ground and the neutral at the service panel and only the service panel is very involved. But basically, if a short occurs the current will flow thru the ground conductor thru the bond and then thru the neutral leading to the power company's transformer. There it will call out to all the other electrons, "Hey Guys! We fot a short out there. We get a free ride!" "Yippee!" say all the other electrons and they all start dashing thru the hot wire towards this short like a crowd of holiday shoppers. But the circuit breaker senses this unexpected crowd and immediately trips. Killjoy.

   If the ground were not bonded to the neutral, then this wouldn't happen. The electrons would have to struggle thru all that dirt which has a pretty high resistance until maybe they ran into a urility pole ground. But that's still enough to shock you.

   Hope this helps.

   ~Peter

1. 
   CPopejoy | May 19, 2004 08:36am | #2

   Peter,

   Well said, and a what great image you've conjured up!

   The point is that a temp power pole IS a service.  And a service is the point (and the only point) where the grounded conductor (neutral) and the equipment grounding conductor (ground) are connected (bonded).  Without that connection, a ground fault won't produce enough current to trip the breaker.

   Cliff

2. 
   G80104 | May 19, 2004 03:39pm | #3

   Thanks for the reply. Never could understand why they fail my sparky 50% of the time,due to them not doing the bonding.