That's the ground wire, to ground your service. It should run from your panel to a 8' long ground rod, pounded into the dirt, and attach that bare 6AWG wire using a ground rod clamp.
The reason you just see it dangling is because trailers get moved, and the wire just gets cut when they move it, and it has to be re-done once the trailer is in its new home. You cant splice it, it has to be a continuous run from the panel to the rod.
The reason you just see it dangling is because trailers get moved, and the wire just gets cut when they move it, and it has to be re-done once the trailer is in its new home. You cant splice it, it has to be a continuous run from the panel to the rod.