In the normal case, the power required by the user is supplied by the mains, and when the mains is cut off or the power is interrupted for other reasons, the generator set is set up to ensure the basic production and life of the user. Such generator sets are mainly located in telecommunications departments, hospitals, industrial and mining enterprises with tight supply of electricity, airports and TV stations. This type of unit is always in standby and provides a continuous supply of power to non-constant loads.