LSRU-115-UR-2 - LSRU Series

Series: LSRU
Questions? Contact Littelfuse Support
External overview image
Roll Over to Zoom
Disclaimer Notice

Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, automotive, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse. "Littelfuse" includes Littelfuse, Inc., and all of its affiliate entities.

The LSRU is a microcontroller-based family of load sensors. The LSRU family of products employ three basic types of control logic: motor control logic, alarm logic and feed control logic.


Motor Control Logic
Several combinations of functions are available in the LSRU, including overcurrent and undercurrent or either overcurrent or undercurrent with variable trip, restart or extended restart delay settings. These various versions of the LSRU trip on the respective fault and then automatically reset after the restart delay expires, in preparation for the next motor start. LSRUs do not trip on undercurrent when the load turns off, this is recognized as a normal condition.
Alarm Logic
The LSRU-AL simply indicates whether the current is between the setpoints or outside of the setpoints. This product is best used with a PLC or other controller where status indication is desired.
Feed Control
The LSRU-FC is a load monitor intended to control feeder mechanisms in a variety of applications. It stops the feeder when the grinder, chipper, saw, auger, etc. nears overload. When the load is reduced to a preset level, the feeder is restarted.

Check Stock Order Samples

Product Literature


Property (Mouseover for details) Value
Input Voltage (V) 18 - 30 Vac
Output Form SPDT
Output Load Rating (VA) Pilot Duty: 480 VA @ 240 Vac; General Purpose: 10 A @ 240 Vac
Timing Accuracy (%) ±10%
Restart Delay Range Manual; 0.5 - 300 s
Undercurrent Trip Point Adjustable through entire Amp range
Current Accuracy (%) ±2%
Current Sensor Range 5 to 25 A
Sensor Hole Size 0.725 in diameter
Motor Acceleration Time Operating Point (s) 2
Power Consumption ≤2 W
Termination Type Torque: 7 in.-lbs.; Wire: 12 - 24 AWG
Mounting Method Surface mount; Four #6 screws 3/4 in in length
Operating Temperature -40° to 70°C (-40° to 158°F)
Dimensions 1.67 H x 2.3 W x 3.56 D in. (42.4 x 58.4 x 90.4 mm)
Weight (lbs/g) 0 Kg
Frequency 50; 60
Check Stock Yes

To request product environmental information, please complete the Product Environmental Information Request Form.