3-Phase Monitor with Adjustable Trip & Restart Delays
The Model 20AB 3-Phase Monitor provides essential protection for industrial systems. This device monitors critical conditions including phase loss, phase reversal, over/under voltage, and voltage unbalance, ensuring operational integrity. Its adjustable trip delay, ranging from 1 to 30 seconds, allows for precise response timing to transient events, preventing unnecessary shutdowns. Furthermore, the adjustable restart delay, configurable from 1 to 500 seconds, facilitates controlled system re-engagement, safeguarding connected equipment. Operating across a 190-480 VAC range with auto-ranging capabilities, it offers versatility for various applications. The unit's auto-reset functionality minimizes manual intervention, contributing to continuous system uptime. With output contacts rated 7.5A at 240VAC resistive, it integrates seamlessly into control circuits. This monitor is designed for reliable performance in demanding industrial environments, offering comprehensive phase protection.
Unv 3Ph Monitor
Specifications
| Reset Type | Auto Reset |
|---|---|
| Operating Voltage | 190-480 VAC |
| Power Consumption | 3.7W at 480V |
| Auto Ranges | Yes |
| Monitored Conditions | Phase Loss, Phase Reversal, Over/Under Voltage and Voltage Unbalance |
| 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 (conforms to 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 | 1x N.C., 1x N.O. 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 |
| Additional Options | /SG = Silver with Gold Flash Contacts |
| Warranty | 5-year Unconditional Warranty |





