If any of return sludge pumps is in off mode, it will be regarded as standbyunit. If fault is found on duty pump, the standby pump will be automatically change over.
没有启动的污泥回流泵作为备用泵，如主泵发生故障，备用泵自动切入。
2
When engaged the Link senses a presence or absence of signal at the input and depending on conditions, places the unit into standby mode.
当从事链接感官的业务或没有信号的输入和有关情况而定，进入待机模式的地方单位。
3
In this paper, two-unit cold standby redundant repairable systems with multiple vacations of a repairman are studied.