Model 258B 3-Phase Monitor
The Model 258B 3-Phase Monitor provides essential protection for industrial systems. This device reliably detects critical power anomalies including phase loss, low voltage, and phase reversal, safeguarding connected equipment from potential damage. Its AUTO Reset functionality ensures continuous operation without manual intervention after a fault clears. Operating across a nominal 208/240VAC range with an adjustable 160-240VAC, it accommodates various applications. The monitor features robust SPDT 10 amp output contacts at 240VAC resistive, ensuring dependable control. With a wide operating temperature range of -20° to +131° F and 0-97% humidity tolerance, the 258B maintains performance in diverse industrial environments. Its 50ms drop out response time and ± 0.1% repeat accuracy contribute to precise system monitoring. This unit offers a practical solution for maintaining operational integrity and extending equipment lifespan.
3Ph Pm Factory Set
Specifications
| Reset Type | AUTO Reset |
|---|---|
| Nominal AC voltage (phase to phase) | 208/240VAC |
| Case Color | Yellow |
| Adjustment range | 160-240VAC |
| Frequency | 60Hz |
| Power consumption | 2.4W |
| Protection Feature | Detects phase loss, low voltage, phase reversal |
| Warranty | Five year unconditional warranty |
| Transient protection | 2500VAC for 10ms |
| Repeat accuracy | ± 0.1% of set point (fixed conditions) |
| Response time | 50ms drop out |
| Dead band | Approx. 2% |
| Output contacts | SPDT 10 amps at 240VAC resistive |
| Expected relay life (Mechanical) | 10 million operations |
| Expected relay life (Electrical) | 100,000 operations at rated load |
| Operating temperature | -20° to +131° F |
| Humidity tolerance | 0-97% w/o condensation |
| Enclosure material | ABS plastic cover |
| Mounting | 8-pin socket (**sold separately) |
| Agency approvals | UL Recognized* and CSA Certified |





