© 2016 Littelfuse Protection Relays & Controls
Protection Relays
Current Monitoring Relays and Transducers
www.littelfuse.com/lsrxxx
Rev: 1-A-062716
LSR-XXX SERIES
Load sensor
Description
The LSR-xxx Series load sensors use current levels to determine
feed rates, tool wear, loss of prime on pumps, mixer viscosity
and all types of overload and underload conditions. They
may also be used to stage pump motors, chillers and other
machinery. These devices combine a current transformer (CT)
with Form C (SPDT) relay contacts to switch alarm circuits,
contactors or any resistive or inductive load. One simple
screwdriver adjustment will calibrate the sensor for all single-
phase or 3-phase applications up to 100hp.
Features
J
Can monitor current of motors up to 100Hp
J
Fine adjustment with 20-turn pot
J
Status LEDs
Specifications
Functional Characteristics
Isolation 600VAC rms
Current Adjustment Range
(Typical) 2-100A
Current Adjustment Range
(Min-Max) 0.5-135A
Trip Setpoint Adjustable to ±1% range
Input Characteristics
Control Power:
LSR-24 24VAC
LSR-115 115VAC
LSR-230 230VAC
Max Current Ratings 135A max. continuous
Output Characteristics
Output Contact Rating (SPDT):
Pilot Duty 480VA @ 240VAC
General Purpose 10A
General Characteristics
Temperature Range -20° to 70°C (-4° to 158°F)
Wire Size #12-24AWG
Hole Size 0.725” diameter
Terminal Torque 7 in.-lbs.
Safety Marks
CSA, CSA-NRTL/C (File #46510)
CE IEC 60947
Dimensions H 42.42 mm (1.67”); W 58.42 mm (2.3”);
D 90.43 mm (3.56”)
Weight 0.4 lb. (6.4 oz., 181.44 g)
Mounting Method Four #6 screws 3/4” in length
Caution: This product should not be relied upon solely for safety of life or safety applications.
Wiring Diagram
TYPICAL WIRING DIAGRAM FOR LOAD LOSS DETECTION
TYPICAL WIRING DIAGRAM FOR OVERLOAD DETECTION
Ordering Information
MODEL LINE VOTAGE
LSR-24 24VAC
LSR-115 115VAC
LSR-230 230VAC
