Protection Relays
Pump Controls and Liquid Level Controls
LLC1 SERIES
Open Board Liquid Level Controls
Description
The LLC1 Series is a single probe conductive liquid level control
designed for OEM equipment and commercial appliances. This
unit may be ordered with fixed fill or fixed drain operation. A
time delay (1-60s) prevents rapid cycling of the output relay.
On adjustable units, the sensitivity adjustment allows accurate
level sensing while ignoring foaming agents and floating
debris. Isolated AC voltage is provided at the probe to prevent
electrolysis. A trickle current of less than 1mA determines the
presence or absence of liquid between the probe and common.
The LLC1 Series printed circuit board is conformal coated to
resist moisture and corrosion.
Operation
Drain (Pump-Down Mode): When the liquid level rises and
touches the probe, a fixed 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. The output
relay then de-energizes and remains de-energized until the liquid
again touches the probe.
Wiring Diagram
P = Probe
L = Load
V = Voltage
∆S = Sensitivity
Adjustment
Fill (Pump-Up Mode): When the liquid level falls below the
probe, a fixed 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.
C
Contacts A, B & C
are isolated.
Metal Tank or use
additional Probe
Connect common to
conductive tank or
an additional probe
as required.
Features & Benefits
FEATURES
BENEFITS
L1 N/L2
Isolated AC voltage
on probe
Prevents scale buildup on the probe
Cost effective design for OEM equipment and
commercial appliances
Open PCB design
Conformally coated PCB
Sensitivity adjustment
Protects against moisture and corrosion
Provides accurate level sensing while ignoring foam
or floating debris
Ordering Information
INPUT
TIME
SENSE
MODEL
OPERATION
MOUNTING
VOLTAGE
DELAY
RESISTANCE
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
Adjustable
120VAC
120VAC
120VAC
120VAC
120VAC
230VAC
230VAC
LLC14A1AX
LLC14A5AX
LLC14B15AX
LLC14B1AX
LLC14B60AX
LLC16A25AX
LLC16A3AX
Drain
Drain
Fill
1s
0.5 in nylon standoffs (3)
0.5 in nylon standoffs (3)
0.5 in nylon standoffs (3)
0.5 in nylon standoffs (3)
0.5 in nylon standoffs (3)
0.5 in nylon standoffs (3)
0.5 in nylon standoffs (3)
5s
15s
1s
Fill
Fill
60s
25s
3s
Drain
Drain
If you don’t find the part you need, call us for a custom product 800-843-8848
© 2016 Littelfuse Protection Relays & Controls
www.littelfuse.com/llc1
Rev: 1-A-062716