Description
The LLC4 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
12VAC is provided at the probe to prevent electrolysis. A trickle
current of less than 1mA 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.
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 energize and remain
energized until the liquid level falls below the probe level. The
output relay de-energize and remain 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 energize and remain energized until the
liquid level rises and touches the probe. The output relay then
de-energize and remain de-energized until the liquid level again
falls below the probe level.

FEATURES BENEFITS
Isolated 12VAC probes Prevents scale buildup on probe
Industry standard 8-pin
octal plug connection Eliminates need for special connectors
Sensitivity adjustment Provides accurate level sensing while ignoring foam
or floating debris