| 摘要 |
PROBLEM TO BE SOLVED: To achieve energy saving by reducing a load on a booster compressor when initial pressure in a supply source of pressurized air lowers.SOLUTION: A booster compressor includes a motor 8 connected to a power source 9, sucks pressurized air from a pressurized air supply source 1, by driving the motor 8, further compresses and discharges the same. A suction side pressure switch 9 operating according to suction pressure is provided on suction piping 2 of the booster compressor, and in an electric circuit connecting the power source with the motor, a magnet switch 10 is equipped for turning on or off energization in association with operation of the suction side pressure switch 9. The suction side pressure switch 9 is constructed so that it operate the magnet switch 10 to turn off energization of the electric circuit when the suction pressure lowers to a first set value lower than a suction pressure specification point which is the suction pressure during normal operation, and to turn on energization of the electric circuit when the suction pressure recovers to a second set value higher than the first set value. |
