201A-AU Series - 3-Phase Voltage/Phase Monitor

Littelfuse Voltage Monitoring Relays

The 201A-AU is a 3-phase, auto-ranging, dual-range voltage monitor that protects 190-480VAC, 50/60Hz motors regardless of size. Has user adjustable 1-30 second trip delay, manual or 1-500 second restart delay, and 2-8% voltage unbalance trip point. The product also provides a user selectable nominal voltage setpoint and the voltage monitor automatically selects between the 200V and 400V range. The Model 201A-AU includes advanced single LED diagnostics, where five different light patterns distinguish between faults and normal conditions.

This unique microcontroller-based voltage and phase-sensing device constantly monitors the 3-phase voltages to detect harmful power line conditions. When a harmful condition is detected, the 201A-AU's output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to acceptable levels.

Access specifications, certifications, check availability and order parts below

Catalog #Input
Voltage (V)
Output
Form
Mounting MethodDimensionsWeight (lbs/g)Compare
201-575-AU-OT475 to 600VACForm CDIN rail or surface mount (plug-in to OT08-PC socket)1.75 in H x 2.38 in W x 4.13 in D (with socket) (44.5 x 60.3 x 104.8 mm)0.7 lb. (11.2 oz. 317.5 g)
201575-AU475 to 600VACForm CDIN rail or surface mount (plug-in to OT08-PC socket)1.75 in H x 2.38 in W x 4.13 in D (with socket) (44.5 x 60.3 x 104.8 mm)0.7 lb. (11.2 oz. 317.5 g)
201A-AU190 to 480VACForm CDIN rail or surface mount (plug-in to OT08-PC socket)1.75 in H x 2.38 in W x 4.13 in D (with socket) (44.5 x 60.3 x 104.8 mm)0.7 lb. (11.2 oz. 317.5 g)
201A-AU-OT190 to 480VACForm CDIN rail or surface mount (plug-in to OT08-PC socket)1.75 in H x 2.38 in W x 4.13 in D (with socket) (44.5 x 60.3 x 104.8 mm)0.7 lb. (11.2 oz. 317.5 g)