| 摘要 |
<p>PURPOSE:To reduce the residual water in a waste water bath, and to facilitate the disposal of a scum when a water level of the waste water bath becomes lower than the lowest water level for safe driving, by stopping the driving of a pump by which the waste water is pumped out, after a predetermined period of time passes by. CONSTITUTION:When a water level of a waste water bath 1 is higher than the lowest water level for safe driving 'LWL', the water level is detected by an upper float 4A of a water level detecting means 4, whereby a driving source 3 is actuated so as to continue the driving of a pump 2. When the water level becomes lower than the lowest water level for safe driving 'LWL' by the continuous driving of the pump 2, the water level is detected by a lower float 4B, whereby a timer 5 in a control disc 6 is actuated. After a predetermined period of time set by the timer 5 passes by, a constant closed contact 5b provided on a circuit 8 for power supply from the power source 7 to the driving source 3 is opened, so as to stop the driving of the pump 2. Residual water in the waste water bath 1 is thus reduced, and the disposal of a scum is facilitated thereby.</p> |
