Littelfuse, Inc. SYMC Protection Relays 201A-9

The 201A-9 is a three-phase voltage monitor designed to protect 190-480 V ac, 50/60 Hz motors, with integrated high-voltage detection. It features an auto-ranging voltage sensor that selects between 200 V and 400 V ranges, advanced LED diagnostics for fault indication, and a dual-range microcontroller-based sensing circuit. The unit has a SPDT relay with a 10 A @ 240 V ac contact rating and supports DIN-rail or surface mounting via the OT08PC socket. Trip delays are 4 seconds for high/low voltage faults and 2 seconds for unbalance or phase reversal faults, with a 2-second restart delay after fault or power loss. It operates within a temperature range of -20° to 70 °C, meets UL 508 standards, and passes IEC 61000-4-2, IEC 61000-4-4, IEC 61000-4-5, and ANSI/IEEE C62.41 surge immunity levels. Dimensions are 44.45 mm H × 60.33 mm W × 104.78 mm D with socket.