© 2016 Littelfuse Protection Relays & Controls
Protection Relays
Pump Controls and Liquid Level Controls
www.littelfuse.com/LLC5
Rev: 1-A-062116
Liquid Level Controls
Description
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.
Features & Benefits
FEATURES BENEFITS
Unique Probe
Protection logic
Probes are protected from scale build up through
pulsed DC signal between the probes.
LED status indicatior
Visual indication of relay engagement in pump-up or
pump-down activity
Isolated 5A
SPDT contacts
Allows control of loads for AC voltage
Accessories
BZ1 Front Panel Mount Kit
Provides an easy method of through-the-panel
mounting of 8- or 11-pin plug-in timers, flashers,
and other controls.
NDS-8 Octal 8-pin Socket
8-pin 35mm DIN rail or surface mount. Rated
at 10A @ 300VAC. Surface mounted with two
#6 (M 3.5 x 0.6) screws or snaps onto a 35 mm
DIN rail. Uses PSC8 hold-down clips.
PSC8 Hold-down Clips
Securely mounts plug-in controls in any position.
Provides protection against vibration. Use with
NDS-8 Octal Socket. Sold in pairs.
Note: use of the PSC8 clips partley covers the LED window of
the LLC5 unit. Use of alternative socket base P1011-6 with its
corresponding hold down clips PSCRB8 do not cover up the LED
window, but the socket base is not DIN rail mountable.
Ordering Information
MODEL
LINE
VOLTAGE
DESCRIPTION
LLC52AA 24VAC
For Drain (pump-down) operation with
adjustable sense resistance
LLC52BA 24VAC
For Fill (pump-up) operation with adjustable
sense resistance
LLC54AA 120VAC
For Drain (pump-down) operation with
adjustable sense resistance
LLC54AAS 120VAC
For Drain (pump-down) operation with
adjustable sense resistance and reverse
connection (#8 low, #6 high)
LLC54AF10 120VAC
For Drain (pump-down) operation with fixed
sense resistance of 10 kΩ
LLC54BA 120VAC
For Fill (pump-up) operation with adjustable
sense resistance
LLC54BAS 120VAC
For Fill (pump-up) operation with adjustable
sense resistance and reverse connection
(#8 low, #6 high)
LLC56AA 230 VAC
For Drain (pump-down) operation with
adjustable sense resistance
If you don’t find the part you need, call us for a custom product 800-843-8848
Wiring Diagram
L1 N/L2
Metal Tank or use
additional Probe
HP = HIGH LEVEL PROBE
LP = LOW LEVEL PROBE
C = PROBE COMMON
V = VOLTAGE
Relay contacts are isolated.
Connect common to
conductive tank. Additional
probe is necessary for non-
conductive or insulated tanks.
LLC5 SERIES
8-PIN
