3-Phase Monitor with Adjustable Trip & Restart Delays
The MODEL 20AA 3-Phase Monitor provides essential protection for industrial equipment. This auto-reset device continuously monitors for critical conditions including phase loss, phase reversal, over/under voltage, and voltage unbalance. Its adjustable trip delays, ranging from 1 to 30 seconds, allow for precise system integration, preventing nuisance trips while ensuring rapid response to genuine faults. Furthermore, the adjustable restart delay, configurable from 1 to 500 seconds, supports controlled equipment re-energization, minimizing potential stress on machinery. Operating across a 190-480 VAC range, this monitor offers reliable performance and system stability. With 2x N.O. isolated output contacts rated at 7.5A at 240VAC, it integrates seamlessly into control circuits. The unit's robust design and 50/60Hz frequency compatibility ensure broad application suitability, contributing to enhanced operational continuity and equipment longevity.
Unv 3Ph Monitor
Specifications
| Model Type | Auto Reset |
|---|---|
| Monitored Conditions | Phase Loss, Phase Reversal, Over/Under Voltage and Voltage Unbalance |
| Indicators | LED Status Indicators |
| Operating Voltage | 190-480 VAC |
| Power Consumption | 3.7W at 480V |
| Auto Ranges | Yes |
| Frequency | 50/60Hz |
| Type of Measurement | RMS |
| Under Voltage Trip | 90% ±1% (% of setpoint) |
| Under Voltage Reset | 93% ±1% (% of setpoint) |
| Over Voltage Trip | 110% ±1% (% of setpoint) |
| Over Voltage Reset | 107% ±1% (% of setpoint) |
| Voltage Unbalance Trip | 2-8%, adjustable |
| Voltage Unbalance Conformance | NEMA |
| Voltage Unbalance Reset | Trip setting minus 0.7% |
| Trip Delay Time (Over, Under, & Unbalanced) | 1-30 sec., adjustable |
| Trip Delay Time (Single-Phasing Faults) | 1 sec., fixed |
| Trip Delay Time (Unbalance > 15%) | 1 sec., fixed |
| Restart Delay | 1-500 sec., adjustable |
| Manual Reset Input | 5V open circuit/500µA short circuit |
| Output Contacts | 2x N.O. (Isolated) |
| Output Contact Rating | 7.5A at 240VAC resistive |
| Operating Temperature | -20° to +140° F |
| Humidity Tolerance | 0-97% w/o condensation |
| Terminal Torque | 3.5 in. lbs. maximum |
| Wire Type | Stranded or solid 14-26 AWG, 1/terminal |
| Enclosure Material | Noryl plastic |
| Mounting | DIN Rail or Surface Mount |
| Dimension Tolerance | ±0.06 |
| Optional Feature | /SG = Silver with Gold Flash Contacts |
| Warranty | 5-year Unconditional Warranty |





