| 摘要 |
PURPOSE:To prevent a change of feed pressure of air and to perform power saving operation, by confirming a compressor, to which an operation instruction is given, to be placed in on-load operation thereafter stopping the other compressor via the predetermined lap time in the time of switching the operation in which the compressor in operation is stopped while the other compressor is operated. CONSTITUTION:During operation of the first compressor 17-1, when the operation is switched to the second compressor 17-2 of smaller capacity corresponding to a decrease of a load, the first compressor 17-1 continues its operation till the second compressor 17-2 reaches its rated load operation, and in the point of time the second compressor 17-2 reaches the rated load, the first compressor 17-1 is stopped. In this way, the first compressor 17-1 enables the operation to be performed with power saving ore than that in the operation in its 50% load, while a change of feed pressure of air is prevented from being generated in the time of switching by providing a lapped operative condition when the operation is switched from the first compressor 17-1 to the second compressor 17-2. |
