If your EMS believes your input voltage is high or low, it will shut the AC down and then after a while will reset and try again. Have you checked your voltage at the pedestal. You may have too high a voltage. If it is borderline as your post indicates, you can bypass the EMS with the little slide switch on the unit. I wouldn't do this unless absolutely necessary as it bypasses the circuitry on the EMS and surges or other electrical problems will get through. If it is erroneously reading a high voltage when the voltage is normal, the EMS could be bad and need repaired or replaced.