It is used to control the level of conductive liquids in tanks and wells. It is connected with hanging electrodes.
Its operation is based on measuring the resistance of the liquid between the electrodes. The relay is activated when the liquid level reaches the upper electrode and is deactivated when the level drops below the middle electrode. The lowest of the three electrodes serves as the reference and can be replaced by ground when the tank is metallic. The use of safe low alternating voltage between the electrodes prevents the phenomenon of electrolysis. The impedance between the electrodes should be less than 20kΩ.
Note: also available in the following variants:
PT414.24 – LEVEL CONTROLLER WITH 24VAC SUPPLY
PT414L – ERROR LOCKOUT LEVEL CONTROLLER: if it detects an error (low level) then it disarms the relay and remains in that state.
PT414B – LEVEL CONTROLLER WITH EXTRA ALARM LEVEL: has an extra relay contact that arms when a fourth electrode gets wet and corresponds to an extra Alarm level.
PT414A – REVERSE FUNCTION LEVEL CONTROLLER: arms the relay when the water level drops below the middle electrode and disarms when it rises to the top electrode (Fill Mode).
