© 2016 Littelfuse Protection Relays & Controls

www.littelfuse.com/

Rev: 1-A-062716

Protection Relays

Pump Controls and Liquid Level Controls

www.littelfuse.com/llc1

LLC1 SERIES

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.

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.

Features & Benefits

FEATURES

BENEFITS

Isolated AC voltage

on probe

Prevents scale buildup on the probe

Open PCB design

Cost effective design for OEM equipment and

commercial appliances

Conformally coated PCB

Protects against moisture and corrosion

Sensitivity adjustment

Provides accurate level sensing while ignoring foam

or floating debris

Wiring Diagram

Open Board Liquid Level Controls

L1 N/L2

Metal Tank or use

additional Probe

C

P = Probe

L = Load

V = Voltage

∆S = Sensitivity

Adjustment

Contacts A, B & C

are isolated.

Connect common to

conductive tank or

an additional probe

as required.

Ordering Information

MODEL

INPUT

VOLTAGE

OPERATION

TIME

DELAY

SENSE

RESISTANCE

MOUNTING

LLC14A1AX

120VAC

Drain

1s

Adjustable

0.5 in nylon standoffs (3)

LLC14A5AX

120VAC

Drain

5s

Adjustable

0.5 in nylon standoffs (3)

LLC14B15AX

120VAC

Fill

15s

Adjustable

0.5 in nylon standoffs (3)

LLC14B1AX

120VAC

Fill

1s

Adjustable

0.5 in nylon standoffs (3)

LLC14B60AX

120VAC

Fill

60s

Adjustable

0.5 in nylon standoffs (3)

LLC16A25AX

230VAC

Drain

25s

Adjustable

0.5 in nylon standoffs (3)

LLC16A3AX

230VAC

Drain

3s

Adjustable

0.5 in nylon standoffs (3)

If you don’t find the part you need, call us for a custom product 800-843-8848