Why do you think that a hot to ground when connecting the service will cause that melting problem?
I aasume that the utility connects the grounded conductore first then the ungrounded conductors. S if the grounded conductor is connected first tehn your massed is grounded through the box and any touching from the hot to the mast will open utility OCPD.
Your drop should be at least 3/0. Here in california i just had the same project i had to go underground feed. with 3/0 conductors in 3" PVC. SCH80.
Good Luck.
You know something just poped up in my head.
The utilities probably did not turn the main off. And they connected the hot conductors first so two hot conductors without a neutral creates 240Volts across the load. (just like a multiwire branch circuit wiring where the neutral is lost and the voltage240 drops across the load according to the resistavity of the load)
So in this case there was only the modem and the GFCI on the load so both devices saw 240v across them.
Just a thought.
Edward
