My understanding about A/C compressor motors is low voltage is the killer - they have to work too hard and wear out. But I don't personally know that for sure - just what I have been told. It could be low voltage just above where the surge protector is set to kick off. We spend most of our time in Mexico in the central mountains where A/C is rarely needed. If there are a lot of RVs running a lot of A/Cs at a beach park and the incoming power and wiring is not adequate you are probably going to see a lot of low voltage. We have been to parks on the coast where the power is so low there is no way anyone can run an A/C. On the other hand with the standard in Mexico at 127 VAC there are many places where high voltage will be seen. You just never know for sure if you travel around. If you stay at only one or two places you get to know what to expect.