Automatic Empty; Leak Detection - FlowLine Switch-Pro LC10 Series Manual

Application Examples
Step Seven

AUTOMATIC EMPTY:

Similar system logic can be used for an automatic empty operation. In
this example, we will use a pump to empty a tank. The system still
consists of a tank with a high level sensor, a low level sensor, and a
pump that is controlled by the controller.
Note: Fail-safe design is critical in an application where the tank is
passively filled. A power failure to the controller or the pump circuits
may cause the tank to overflow. A redundant high alarm is critical to
prevent an overflow.
Connect the pump to the NO side of the relay. In this case, Invert
should be OFF, when the relay is energized, the pump will run and
empty the tank. The relay indicator will correspond directly to the
on/off status of the pump.
Note: If the pump motor load exceeds the rating of the controller's
relay, a stepper relay of higher capacity must be used as part of the
system design.

LEAK DETECTION:

A leak detection switch is installed either inside the interstitial space of the tank or through the outer wall. The
switch will remain wet 99.99% of the time. Only when liquid comes into contact with the switch will the relay
close to activate an alarm.
The alarm is connected to the NC side of the relay to allow for a power failure alarm.
Note: The sensor is normally dry. In this condition, we want the relay to be energized so the alarm does not
sound: i.e., the Red relay LED should be on whenever the Input LED is Amber. So we turn Invert On. If liquid
comes into contact with the switch, the switch activates, the relay de-energizes, and the alarm sounds.
| 16 MN301510 Rev A1