|
In this example, the level of liquid in the tank is controlled by the
electrodes E2 and E3 of level switch 61F. The liquid level may not reach
E3 when the pump idles while the material is being supplied or when the
filter is clogged with foreign matter.
In such a case, timer H3JA can be operated simultaneously with the start
of the supply pump to detect that liquid level has not reached E3 after
the lapse of a predetermined time. The timer then causes the alarm to
sound and pump to be stopped.
|