Model 21-LM 3-Phase Monitor (Manual Reset, 95-120 VAC)
The Model 21-LM 3-Phase Monitor provides essential protection for industrial systems. This manual reset device operates within a 95-120 VAC range, ensuring compatibility with common power configurations. It continuously monitors critical conditions including phase loss, phase reversal, over/under voltage, and voltage unbalance. Adjustable trip delay times, from 1 to 30 seconds, allow for precise system integration and nuisance trip avoidance. The robust SPDT 10A output contacts at 240VAC resistive facilitate reliable control and system integration. Its design supports both Wye and Delta systems, offering versatile application across various industrial setups. With a power consumption of 3.7W at 120V, it maintains efficiency. This monitor is engineered for consistent performance in demanding environments, contributing to operational stability and equipment longevity. Its UL Recognized status further assures adherence to established safety standards.
Universal 3Ph Monitor
Specifications
| Model Type | Manual Reset |
|---|---|
| Operating Voltage | 95-120 VAC |
| Power Consumption | 3.7W at 120V |
| Auto Ranges | No |
| 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 Unbalance > 15%) | 1 sec., fixed |
| Trip Delay Time (Reverse Phase) | 1 sec., fixed |
| Restart Delay | 1-500 sec., adjustable |
| Manual Reset Input | 5V open circuit/500µA short circuit |
| Output Contacts | SPDT 10A at 240VAC resistive |
| Operating Temperature | -20° to +140° F |
| Humidity Tolerance | 0-97% w/o condensation |
| Enclosure Material | Noryl plastic |
| Mounting | 8-Pin Socket (**sold separately) |
| Recommended Socket | 51x120 |
| Additional Options | /SG = Silver with Gold Flash Contacts |
| Agency Approval | UL Recognized (U.S. and Canada) (For use in a Pollution Degree 2 Environment) |
| Neutral Connection | Not required |
| System Compatibility | Wye or Delta systems |
| Recommended Fuse | 1A 600VAC |
| Warranty | 5-year Unconditional Warranty |
