In article , stryped wrote:

The main pannel had two spots left. I added a 100 amp breaker in the
main panel to the 100 amp sub panel. the wiring between the two was
the correct size for 100 amps. (I checked when I did this several
years ago.)

Let's double-check, OK? Please answer all of these questions:

What type of wire?
What gauge?
How many conductors did you run to the subpanel?
What are they connected to?
Does the subpanel have separate busses for neutral and ground?
Are they connected to each other, or electrically separate?
How are the neutral and ground busses in the subpanel connected to the main
panel?