well it has been 2 seasons for approx 9 months plugged into a 30 amp receptacle. I have never seen the power monitor in the motor home read less than 116 or more than 120. usually 118 . steady, no up,no down. A friend of mine watched for a season. bought one this year. one week later more than 7 RV's lost micro waves, refrigerators boards of all descriptions etc. My friend did not lose anything. his unit placed in front of his surge protector stopped the spike, reset and went on working. His power stays at 114 for some reason. When measured the power here is usually 129 and higher, tripping surge protectors daily. I do not have that problem. My friend does not have that problem, and now another friend has bought one without the need for a surge guard.
the unit shuts down even when physical heat is too much, like putting it in a plastic box with a lid in the heat; it shuts off.
we can not prove any of this but we sure can use the system. Ecowise.