Littelfuse, Inc. Monitor - Relay Output 601

The 601 is a fully-programmable three-phase voltage and frequency monitor designed to protect motors from phase loss, reversal, voltage and frequency deviations, unbalance, and rapid cycling. It features a three-digit LED display for real-time monitoring of voltage, frequency, and unbalance, and supports remote communication via RS485 Modbus RTU with the RS485MS-2W module. The relay has programmable trip delays for voltage/frequency faults (1-50 seconds) and single-phase faults (1-50 seconds), with two restart delay timers (RD1: 0, 2-500 seconds; RD2: 2-500 seconds) and selectable automatic or manual restart. Operating voltage range is 190-480 V ac, with a pilot duty output contact rating of 480 VA at 240 V ac. It mounts via surface mount with four #8 screws or DIN rail, measures 77.47 mm H × 97.79 mm W × 128.27 mm D, and operates from -20°C to 70°C. Certified to UL 508 and CSA C22.2 No. 14.