Parallel units accommodating device for e.g. vacuum supply system, has unit for formation of difference value between maximum and minimum running times in one of parallel units, where difference value is compared with predetermined value

摘要

The device has a formation unit (17) for forming a difference value between maximum running time and minimum running time in one of parallel units (2-4), where the difference value is compared with a predetermined threshold value, and exceeding limit value is displayed by an alarm transmitter (18). Runtime counters (9-11) are provided for acquisition of overall operation hours of each parallel unit, and resettable runtime counters (12-14) are made reset according to the excess of the threshold value. An independent claim is also included for a method for monitoring a device accommodating parallel units.