Protection Relays
Pump Controls and Liquid Level Controls
LLC4 SERIES
Octal Plug-In Liquid Level Controls
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.
P = 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.
8-PIN
Wiring Diagram
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.
Metal Tank or use
additional Probe
L1
N/L2
Features & Benefits
FEATURES
Isolated 12VAC probes
Industry standard 8-pin
octal plug connection
Sensitivity adjustment
BENEFITS
Prevents scale buildup on probe
Eliminates need for special connectors
Provides accurate level sensing while ignoring foam
or floating debris
Ordering Information
MODEL
INPUT
VOLTAGE
OPERATION
TIME
DELAY
SENSE RESISTANCE
MODEL
INPUT
VOLTAGE
OPERATION
TIME
SENSE RESISTANCE
DELAY
LLC42A10A
LLC42A1A
LLC42B15A
LLC44A10A
LLC44A15A
LLC44A1A
LLC44A2A
LLC44A4A
LLC44A5A
24VAC
24VAC
24VAC
120VAC
120VAC
120VAC
120VAC
120VAC
120VAC
Drain
Drain
Fill
Drain
Drain
Drain
Drain
Drain
Drain
10s
1s
15s
10s
15s
1s
2s
4s
5s
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
LLC44B1A
LLC44A60A
LLC44B20A
LLC44B2A
LLC44B30A
LLC44B4A
LLC44B5A
LLC44B5F100
120VAC
120VAC
120VAC
120VAC
120VAC
120VAC
120VAC
120VAC
Fill
Drain
Fill
Fill
Fill
Fill
Fill
Fill
1s
60s
20s
2s
30s
4s
5s
5s
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
Adjustable 1 - 250kΩ
Fixed 100kΩ
If you don’t find the part you need, call us for a custom product 800-843-8848
© 2017 Littelfuse Protection Relays & Controls
www.littelfuse.com/llc4
www.littelfuse.com/
Rev: 1-A-020817
Protection Relays
Pump Controls and Liquid Level Controls
LLC4 SERIES
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. 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.
PHST-38QTN Electrode
Designed for a maximum steam pressure of
240 PSI; 400° F UL353 Recognized.
.
LLP-24 Threaded Probe (24”)
Threaded stainless steel probe measuring 24”
(61 cm) long. For use with PHST-38QTN liquid
level control electrodes.
Specifications
Control
Type
Sensing Voltage
Sensing Resistance
Sensing Resistance
Tolerance
ON/OFF (single level) resistance sensor with
built-in time delay to prevent rapid cycling
12VAC
Fixed or adjustable to 250KΩ
Adjustable: 1K ±500Ω at low end;
250K ±25% at high end
Factory fixed: ±10% or 500Ω, whichever
is greater
24, 120, or 230VAC
-15%, +20%
-20%, +10%
50/60 Hz
Electromechanical relay
Isolated, SPDT
4A resistive @ 240VAC;
1/10 hp @ 240VAC
IEEE C62.41-1991 Level A
≥ 1500V RMS between input, output & probe
Plug-in socket
Octal 8-pin plug-in
H
73.9 mm (2.91”);
W
60.7 mm (2.39”);
D
45.2 mm (1.78”)
Input
Voltage
Tolerance
24VAC
120 & 230VAC
AC Line Frequency
Output
Type
Form
Rating
Protection
Surge
Isolation Voltage
Mechanical
Mounting
Termination
Dimensions
Environmental
Operating/Storage
Temperature
Weight
-20° to 60°C/-40° to 80°C
≅
6 oz (170 g)
© 2017 Littelfuse Protection Relays & Controls
www.littelfuse.com/llc4
www.littelfuse.com/
Rev: 1-A-020817
RF/Wirelessly
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