John.. This wasn't in a trailer park, this was up in the Sequoia Nat'l Park.:P There was no pedestal, the meter and disconnect are on the utility pole along the dirt road that feeds a small tract of trailers/mobile homes. From the disconnect to the trailer are 3 - #1 THWN. No ground wire is in the conduit. It's a long uphill run to the trailer that I paced off being between 250-260'
I know the frame of the trailer is bonded to the panel as I pulled the skirting off in the panel location. I found a ground rod and the water bond (most of the water piping is PVC, but a steel section was bonded). My problem is that there was a direct phase to ground short and no OCPD opened up. The tin on the mobile home became energized, the metal panel can/ground bar and everything else lit up a hot stick. I measured 117V between the ground bar and the isolated neutral bar. I measured 115V between the metal of the home and the isolated neutral bar.
This tells me that there is not a sufficient path for current back to the transformer from the metal structure of this home in order to operate an OCPD during a fault.
I know that the neutral is only supposed to be bonded in one location, but how else do I keep these people from getting lit up if something else gets chewed on?? GFCI ALL the breakers? (The panel is twined out, so this would be quite a feat.)
