No, your pump should not burn out unless something happened to break the siphon. The skimmer box inside the tank should keep some water in it in the event the power goes out as should the intake box on the outside. Once water stops overflowing from the tank into the skimmer box, the levels in the skimmer and intake boxes equalize and there is still water in the siphon tube. Once the power kicks back on, the return pump sends water into the tank, then into the skimmer box, essentially getting the siphon out of equalibrium making water move from the skimmer box into the intake box. Where folks seem to have problems is when the water level gets low in the sump and you start pumping air into the tank which ends up in the siphon tube breaking the siphon. In this case, the return pump emptys the sump and water no longer moves from the skimmer box to the intake box. That is the advantage of a drilled overflow - there's no siphon to break.
