The LLC4 series combines resistance-sensing circuitry with solid-state timing to provide single-probe level maintenance. On adjustable units, the sensitivity adjustment allows accurate level sensing while ignoring foaming agents and floating debris. Isolated 12 V ac is provided at the probe to prevent electrolysis. A trickle current of less than 1 mA determines the presence or absence of conductive liquid between the probe and common. The LLC4 series can be used with many types of low voltage (resistance changing) transducers to perform other control functions like temperature limit control, photo limit control, condensation sensing, and ice sensing. This unit features an industry standard, eight-pin octal plug connection.
Operation
Drain (pump-down mode): When the liquid level rises and touches the probe, the time delay begins. This time delay prevents rapid cycling of the output relay and its load. At the end of the time delay, the output relay energizes and remains energized until the liquid level falls below the probe level. The output relay de-energizes and remains de-energized until the liquid rises and touches the probe.
Fill (pump-up mode): When the liquid level falls below the probe, the time delay begins. This time delay prevents rapid cycling of the output relay and its load. At the end of the time delay, the output relay energizes and remains energized until the liquid level rises and touches the probe. The output relay then de-energizes and remains de-energized until the liquid level again falls below the probe level.
- Isolated 12 V ac voltage on probes
- Industry standard 8-pin octal plug connection
- Sensitivity adjustment
- Prevents scale buildup on the probes
- Eliminates need for special connectors
- Provides accurate level sensing while ignoring foam or floating debris
LLC4 Parts
Filters
Part Number | Actions | Input Voltage (V) | Output Form | Time Delay Range (s) | Termination Type | Mount Method | Dimensions | Weight (kg) | Control Type | Input AC Line Frequency (Hz) | Input Tolerance (%) | Output Load Rating (VA) | Output Type | Sense Resistance Tolerance | Sense Resistance (Ω) | Sense Voltage | Storage temperature (°C) | Surge Protection |
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Part Number | Actions | Input Voltage (V) | Output Form | Time Delay Range (s) | Termination Type | Mount Method | Dimensions | Weight (kg) | Control Type | Input AC Line Frequency (Hz) | Input Tolerance (%) | Output Load Rating (VA) | Output Type | Sense Resistance Tolerance | Sense Resistance (Ω) | Sense Voltage | Storage temperature (°C) | Surge Protection | |
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120 Vac | Non-isolated SPST and isolated SPDT contacts | 1 s fixed | 0.25 in. (6.3 mm) male quick connect terminals | 3.5 H x 2.75 W x 2 D in. (88.9 x 69.9 x 50.9 mm) | 0 Kg (kilogram) | ON/OFF (single level) resistance sensor with built-in time delay to prevent rapid cycling | 50 / 60 | -0.3 | 10 A resistive @ 120/240 Vac and 28 Vdc; 1/3 hp @ 120/240 Vac | Electromechanical relay | Guaranteed range | Adjustable to 250 | Low voltage AC between probe and common; isolated from input and ouput | IEEE C62.41-1991 Level A | |||||
120 Vac | Non-isolated SPST and isolated SPDT contacts | 5 s fixed | 0.25 in. (6.3 mm) male quick connect terminals | 3.5 H x 2.75 W x 2 D in. (88.9 x 69.9 x 50.9 mm) | 0 Kg (kilogram) | ON/OFF (single level) resistance sensor with built-in time delay to prevent rapid cycling | 50 / 60 | -0.3 | 10 A resistive @ 120/240 Vac and 28 Vdc; 1/3 hp @ 120/240 Vac | Electromechanical relay | Guaranteed range | Adjustable to 250 | Low voltage AC between probe and common; isolated from input and ouput | IEEE C62.41-1991 Level A | |||||
120 Vac | Non-isolated SPST and isolated SPDT contacts | 15 s fixed | 0.25 in. (6.3 mm) male quick connect terminals | 3.5 H x 2.75 W x 2 D in. (88.9 x 69.9 x 50.9 mm) | 0 Kg (kilogram) | ON/OFF (single level) resistance sensor with built-in time delay to prevent rapid cycling | 50 / 60 | -0.3 | 10 A resistive @ 120/240 Vac and 28 Vdc; 1/3 hp @ 120/240 Vac | Electromechanical relay | Guaranteed range | Adjustable to 250 | Low voltage AC between probe and common; isolated from input and ouput | IEEE C62.41-1991 Level A | |||||
120 Vac | Non-isolated SPST and isolated SPDT contacts | 1 s fixed | 0.25 in. (6.3 mm) male quick connect terminals | 3.5 H x 2.75 W x 2 D in. (88.9 x 69.9 x 50.9 mm) | 0 Kg (kilogram) | ON/OFF (single level) resistance sensor with built-in time delay to prevent rapid cycling | 50 / 60 | -0.3 | 10 A resistive @ 120/240 Vac and 28 Vdc; 1/3 hp @ 120/240 Vac | Electromechanical relay | Guaranteed range | Adjustable to 250 | Low voltage AC between probe and common; isolated from input and ouput | IEEE C62.41-1991 Level A | |||||
120 Vac | Non-isolated SPST and isolated SPDT contacts | 60 s fixed | 0.25 in. (6.3 mm) male quick connect terminals | 3.5 H x 2.75 W x 2 D in. (88.9 x 69.9 x 50.9 mm) | 0 Kg (kilogram) | ON/OFF (single level) resistance sensor with built-in time delay to prevent rapid cycling | 50 / 60 | -0.3 | 10 A resistive @ 120/240 Vac and 28 Vdc; 1/3 hp @ 120/240 Vac | Electromechanical relay | Guaranteed range | Adjustable to 250 | Low voltage AC between probe and common; isolated from input and ouput | IEEE C62.41-1991 Level A | |||||
230 Vac | Non-isolated SPST and isolated SPDT contacts | 25 s fixed | 0.25 in. (6.3 mm) male quick connect terminals | 3.5 H x 2.75 W x 2 D in. (88.9 x 69.9 x 50.9 mm) | 0 Kg (kilogram) | ON/OFF (single level) resistance sensor with built-in time delay to prevent rapid cycling | 50 / 60 | -0.3 | 10 A resistive @ 120/240 Vac and 28 Vdc; 1/3 hp @ 120/240 Vac | Electromechanical relay | Guaranteed range | Adjustable to 250 | Low voltage AC between probe and common; isolated from input and ouput | IEEE C62.41-1991 Level A | |||||
230 Vac | Non-isolated SPST and isolated SPDT contacts | 3 s fixed | 0.25 in. (6.3 mm) male quick connect terminals | 3.5 H x 2.75 W x 2 D in. (88.9 x 69.9 x 50.9 mm) | 0 Kg (kilogram) | ON/OFF (single level) resistance sensor with built-in time delay to prevent rapid cycling | 50 / 60 | -0.3 | 10 A resistive @ 120/240 Vac and 28 Vdc; 1/3 hp @ 120/240 Vac | Electromechanical relay | Guaranteed range | Adjustable to 250 | Low voltage AC between probe and common; isolated from input and ouput | IEEE C62.41-1991 Level A |
LLC4 Applications
- For use in liquid pumping operations in pump-up or pump-down applications