The voltage/Surge protector is good for an automatic protection of the home appliance in case of under-voltage and electricity-stoppage. For instance, it may be always harmful to the normal operation, cut their service life, or even burn down the compressor motors for air-conditioners, refrigerators and frezzing cabinates if the supply voltage is too low or high. Especially, instant power stoppage and restarting supply with the electricity net creates a strong voltage impact which is very hazardous and may damge the compressors.