Littelfuse, Inc. SYMC Protection Relays 250A

The 250A series from Quarktwin Technology Ltd. is a three-phase voltage monitoring relay designed for motors operating within a voltage range of 190,Äì480 V ac at 50/60 Hz. It provides protection against low and high voltage conditions, voltage unbalance, single-phase issues, and phase reversal. The device features a microcontroller-based design that continuously monitors voltage levels and activates a relay output to disconnect the load when harmful conditions are detected, with a user-selectable trip delay. The monitor includes advanced LED diagnostics that indicate various operational states, such as normal operation and specific fault conditions. It has a dual-range capability, automatically selecting between 200 V and 400 V, and allows for adjustable restart delays after a fault. The output relay is rated for 10 A at 240 V ac and supports a variety of applications, including fan motors, air conditioners, and small conveyor motors. The operating temperature range is -40¬8 to 70 ¬8C, and it is compliant with UL and CSA standards.