Protection Relays
Pump Controls and Liquid Level Controls
LLC2 SERIES
Open Board Liquid Level Controls
Description
The LLC2 Series is a dual-probe conductive liquid level control
designed for OEM equipment and commercial appliance
applications. Models are available for fill or drain operation.
Transformer isolated 12VAC is provided at the probes to prevent
electrolysis. A trickle current of less than 1mA determines the
presence or absence of liquid between the probes and common.
On adjustable units, the sensitivity adjustment allows accurate
level sensing while ignoring foaming agents and floating debris.
The LLC2 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 high probe, the output relay energizes and remains
energized until the liquid level falls below the low probe. The
output relay then de-energizes and remains de-energized until
the liquid again touches the high probe.
V = Voltage
L = Low Probe
H = High Probe
C = Probe Common
P = Probe
∆S = Sensitivity
Adjustment
NC = Normally
Closed
NO = Normally
Open
Wiring Diagram
Fill (Pump-Up Mode):
When the liquid level falls below the low
probe, the output relay energizes and remains energized until
the liquid level rises and touches the high probe. The output
relay then de-energizes and remains de-energized until the liquid
level again falls below the low probe.
Features & Benefits
FEATURES
Isolated 12VAC probes
Open PCB design
Conformally coated PCB
Sensitivity adjustment
BENEFITS
Prevents scale buildup on the probes
Cost effective design for OEM equipment and
commercial appliances
Protects against moisture and corrosion
Provides accurate level sensing while ignoring foam
or floating debris
Metal Tank or use
additional Probe
L1
N/L2
Connect common to conductive tank. Additional
probe is necessary for non-conductive or
insulated tanks.
Accessories
Ordering Information
MODEL
INPUT
VOLTAGE
OPERATION
TERMINATION
SENSE
RESISTANCE
P1015-13
(AWG 10/12),
P1015-64
(AWG 14/16),
P1015-14
(AWG 18/22)
Female Quick Connect
These 0.25 in. (6.35 mm) female terminals are
constructed with an insulator barrel to provide
strain relief.
P1015-18 Quick Connect to Screw Adapter
Screw adapter terminal designed for use with
all modules with 0.25 in. (6.35 mm) male quick
connect terminals.
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.
LLC24A2AN
120VAC
Drain
Drain
Fill
Fill
Fill
Drain
Terminal block
Terminal block
0.25”
Quick connect
0.25”
Quick connect
Terminal block
0.25”
Quick connect
Adjustable
to 100kΩ
Fixed 50kΩ
Adjustable
to 100kΩ
Fixed 26kΩ
Fixed 50kΩ
Fixed 25kΩ
LLC24A2F50N
120VAC
LLC24B1AC
LLC24B1F26C
120VAC
120VAC
LLC24B2F50N
120VAC
LLC26A1F25C
230VAC
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/llc2
www.littelfuse.com/
Rev: 1-A-062716
Protection Relays
Pump Controls and Liquid Level Controls
LLC2 SERIES
Specifications
Control
Type
Sense Voltage
Sense Resistance
Sense Resistance Tolerance
Input
Voltage
Tolerance
24VAC
120 & 230VAC
AC Line Frequency
Output
Type
Form
Rating
Life
Protection
Isolation Voltage
Mechanical
Mounting
Termination
Dimensions (Open Board)
Environmental
Operating/Storage
Temperature
Coating
Weight
Resistance sensing for high & low level
detection of conductive liquids
12VAC at probe terminals
Fixed or adjustable to 100KΩ
Adjustable: guaranteed range
Fixed: ±10%
24, 120, or 230VAC
-15% - 20%
-20% - 10%
50/60 Hz
Electromechanical relay
Isolated, SPDT
10A resistive @ 120/240VAC & 28VDC;
1/3 hp @ 120/240VAC
Mechanical - 1 x 10
7
; Electrical - 1 x 10
5
≥ 1500V RMS between input, output, & probe
Surface mount with two or four #6
(M3.5 x 0.6) screws
0.25 in. (6.35 mm) duplex male quick connect
terminals. Terminal blocks for up to #14 AWG
2.5 mm
2
) wire
H
101.6 mm (4.0”);
W
76.2 mm (3.0”);
D
50.8 mm (2.0”)
Mounting Dimensions
0.163 (4.14)
DIAGRAM
KEY
W
4.0
(101.6)
MODEL NUMBERS ENDING IN:
N
C
0.440”
(11.176 mm)
3.620”
(91.948 mm)
2.120”
(53.848 mm)
0.25
(6.35)
3.5
(88.9)
2.5
(63.5)
0.25
(6.35)
0.250”
(6.350 mm)
3.500”
(88.900 mm)
2.500”
(63.500 mm)
0.250”
(6.350 mm)
X
Y
Z
0.44
(11.35)
3.62
(91.9)
2.12
(53.8)
0.19
(4.83)
3.0
(76.2)
0.5
(12.7)
0.190”
(4.826 mm)
2.0
(50.8)
-20° to 55°C / -40° to 80°C
Printed circuit board is conformal coated to
resist moisture and corrosion
≅
9 oz (255 g)
© 2016 Littelfuse Protection Relays & Controls
www.littelfuse.com/llc2
www.littelfuse.com/
Rev: 1-A-062716
