re: Condensation shorting A/C Handler in attic

seal any openings - warm moist air in the attic is getting into the unit and condensing

if i had to guess the rubber grommets that seal around the piping into the units were not installed properly or a dry rotted

or

either an electrical knockout is missing and not used or the electrician didnt seal the penetration correctly.

if those are not the case feel around for air flowing out of panel seams.


From looking at the unit you linked, this is a draw-through fan configuration (which means the fan is located up stream of the coil section and pulls the air across the coil) because the air handling section before the coil is in a negative pressure, it will actually suck in attic air if there are leaks in to the cabinet.

EDIT:

looking at the installation manual in the "documentation" tab link, it appear the control section is on the top of the unit and it has the electrical knockouts in that cabinet section. i would look for leaks at the electrical penetrations first.