Pure sine wave inverter can better load high-power electrical products, such as motors, compressors, relays, etc.. Because inductive load products need the current startup about 5-7 times than a normal operation . For example, a refrigerator need normal operation about 150 watts,But the starting power up to 1000 watts or more. Further, since the inductive load in an instant power or disconnect the power, it will produce a counter electromotive force voltage, peak voltage which is far greater than the inverter can withstand voltage, it can easily lead to the inverter instantaneous overload , affect the service life of the inverter. Therefore, such a high electrical power supply waveform requirements. If you don't know whether modify or pure sine wave you choose. Hope it will help you.