LLC52AA - LLC Series

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Littelfuse Pump Controls and Liquid Level Controls
The LLC5 provides dual probe conductive liquid level control in a convenient octal plug-in package. Models are available for fixed fill or drain operation. Isolated, pulsed DC voltage on the probes prevents electrolytic plating. Less than 1 mA of current is used to sense the presence of conductive liquid between the probes and common. On adjustable units, the sensitivity adjustment eliminates false tripping caused by floating debris and foaming agents.


Operation
Drain (Pump-Down Mode): When the liquid level rises and touches the high level probe, the output relay and LED energize and remain energized until the liquid level falls below the low level probe. The output relay and LED de-energize and remain de-energized until the liquid rises and touches the high level probe.
Fill (Pump-Up Mode): When the liquid level falls below the low level probe, the output relay and LED energize and remain energized until the liquid level rises and touches the high level probe. The output relay and LED de-energize and remain de-energized until the liquid level again falls below the low level probe.

Property (Mouseover for details) Value
Input Voltage (V) 24VAC
Input Tolerance (%) -0.35
Input AC Line Frequency (Hz) 50/60Hz
Output Type Electromechanical relay
Output Form Isolated SPDT
Output Load Rating (VA) 5A resistive @ 240VAC; 1/10hp @ 240VAC
Response Time (ms) Debounce time delay <1s
Sense Voltage Pulsed DC at probe terminals
Sense Resistance (Ohms) Adjustable to 100kΩ
Sense Resistance Tolerance 1K ±500 Ω at low end; 100kΩ ±25% 0% at high end
Control Type Resistance sensing for high and low level detection of conductive liquids
Isolation Voltage (V) ≥1500V RMS between input output and probe
Termination Type Octal 8-pin plug-in
Mounting Method Plug-in socket
Operating Temperature -20° to 60°C (-4°F to 140°F)
Storage Temperature (F/C) -40° to 80°C (-40°F to 176°F)
Dimensions 3.01 x 2.39 x 1.78 in. (76.5 x 60.7 x 45.2mm)
Weight (lbs/g) ≅6.0oz (170g)