Model 21 3-Phase Monitor (Auto Reset, 190-480 VAC)

The Model 21 3-Phase Monitor provides essential protection for industrial electrical systems. Its auto-reset functionality minimizes downtime by automatically restoring operation after fault conditions clear, enhancing operational continuity. This device monitors critical parameters including phase loss, phase reversal, over/under voltage, and voltage unbalance across a wide 190-480 VAC operating range. Such comprehensive monitoring helps prevent equipment damage and extends machinery lifespan. With adjustable trip delay times from 1-30 seconds, it offers precise control over system response to transient conditions. The unit's robust design, featuring Noryl plastic enclosure material and a 5-year unconditional warranty, ensures long-term reliability in demanding environments. It is compatible with both Wye and Delta systems and does not require a neutral connection. UL Recognized for both U.S. and Canada, it adheres to safety standards for pollution degree 2 environments.