Littelfuse, Inc. Industrial Relays 455

The 455 series is a three-phase, dual-range voltage monitor designed to protect 190-480 V ac, 50/60 Hz motors by simultaneously monitoring line and load sides, providing protection before motor start-up. It automatically selects between 200 V and 400 V ranges based on the nominal voltage setpoint and features adjustable trip delays of 2-30 seconds, restart delays of 2-300 seconds (manual or automatic), and a 2-8% adjustable voltage unbalance trip point. Power is drawn from line side connections, eliminating the need for separate control power. The unit includes an infrared LED for communication with the Informer-MS diagnostic tool, an SPDT output contact rated for 10 A general purpose, and operates in ambient temperatures from -40 °C to 70 °C. Dimensions are 74.4 mm height, 133.9 mm width, and 74.9 mm depth, with mounting via #8 screws. It complies with UL 508, CSA C22.2 No. 14, and IEC 60947-6-2.