Littelfuse, Inc. SYMC Protection Relays 250A-MET

The 250A-MET is a three-phase voltage monitor designed for use with fire control panels, providing low-voltage and phase reversal protection within a 190-480 V ac range. It features two independent Form C contacts: the left contacts energize under normal voltage conditions and de-energize during faults, while the right contact activates only during reverse-phase conditions and has no high-voltage protection. It includes adjustable restart delay, auto-ranging voltage sensing, and LED diagnostics. The unit has a DPDT relay output rated for 10 A at 240 V ac, operates within a temperature range of -40° to 70 °C, and is mounted using #8 screws. Its dimensions are 74.4 mm high, 133.9 mm wide, and 74.9 mm deep. It complies with UL 508 and CSA 22.2 No. 14 standards.