I had a "ball failure" (actually it was the mechanisms spring nut under the ball cup that is suppose to hold the ball in the cup) one day when I hit a bad bridge to roadway transition bump. The safety chains kept the trailer (boat not TT) attached and neither the power cable nor the breakaway switch pin pulled loose. No real damage but another item I check now each time I hook up.
The point being that unless you loose the whole hitch, the break away and your power cable are unlikely to come loose. Unless you have short cables or long safety chains.