Littelfuse LSRX Self-Powered AC Current Sensor Load Relay 5-200A

The Littelfuse LSRX is a self-powered AC current sensor relay designed to monitor electrical loads from 5 to 200 amps continuously. This innovative device energizes its output contact whenever 4.5 amps or greater is detected, making it ideal for verifying motor operation and equipment status without requiring external power.

Key Features:

• Self-powered design draws energy from the monitored conductor—no external power source needed
• Operating range: 5-200A continuous with minimum pull-in at 4.5A typical (7.0A maximum)
• SPST Form A relay output rated for 480VA @ 240VAC pilot duty or 5A @ 240VAC general purpose
• Built-in LED indicator provides visual confirmation of relay status
• Accommodates conductors up to 0.7 inches in diameter
• Fast-on quick-connect terminals for simplified installation
• Combines current transformer, transducer, and high-current relay in one compact unit

Commonly used as a current proof relay to confirm motor operation, the LSRX also excels at interlocking fans, compressors, and motors; monitoring equipment status including feed rates, tool wear, pump prime loss, and mixer viscosity; staging pump motors and chillers; and switching alarm circuits or contactors. The integrated design eliminates the need for separate current transformers while providing isolation between monitored and control circuits.