Model B258B-400 3-Phase Monitor
The Model B258B-400 3-Phase Monitor offers essential protection for industrial systems operating at 120VAC nominal and 400Hz. This device safeguards against critical conditions including phase loss, low voltage, and phase reversal, ensuring operational continuity. Its AUTO Reset functionality minimizes downtime by automatically restoring monitoring after fault clearance. With a robust design, it features transient protection up to 2500VAC for 10ms and maintains performance across an operating temperature range of -20° to +131° F. The unit's output contacts are SPDT 10 amps at 240VAC resistive, providing reliable control. Humidity tolerance up to 97% without condensation enhances its versatility in various environments. A repeat accuracy of ± 0.1% of set point ensures precise operation. UL Recognized and CSA Certified, the B258B-400 is engineered for dependable system monitoring and a long operational life.
3Ph Pwr Mon
Specifications
| Reset Type | AUTO Reset |
|---|---|
| Nominal AC voltage (phase to phase) | 120VAC |
| Case Color | Gray |
| Adjustment range | 85-120VAC |
| Frequency | 400Hz |
| Power consumption | 1.4W |
| 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 |





