A257B-480V-400HZ
The A252B 3-Phase Monitor provides essential protection for industrial systems. It detects critical conditions such as phase loss, low voltage, and phase reversal, safeguarding connected equipment from operational anomalies. This proactive monitoring capability helps prevent costly damage and ensures continuous system functionality. Featuring an automatic reset type and a rapid 0.05-second response time, the unit ensures minimal disruption and quick recovery from transient events. Its output contacts are rated at 5A at 115VAC resistive, offering reliable control for various applications. The robust design includes 2500V transient protection for 10ms, significantly enhancing system integrity against electrical disturbances. Operating effectively across a -20° to 131° F temperature range, this monitor maintains consistent performance in diverse industrial environments. This device is engineered for dependable, utility-driven performance in critical three-phase applications.
The Model 257 continuously monitors 3-phase power lines for abnormal
conditions. When properly adjusted, the Model 257 monitor will detect
phase loss on a loaded motor even when regenerated voltage is present.
This device consists of a solid-state voltage and phase-angle sensing
circuit, driving an electromechanical relay. When correct voltage and
phase rotation are applied, the internal relay will energize. A fault
condition will de-energize the relay. When the fault is corrected, the
monitor will automatically reset (a manual reset version is also
available). The Model 257 does not require a neutral connection and
can be used with Wye or Delta systems. Voltage ranges are sufficiently
wide to allow for proper adjustment to existing conditions. Both TRIP
and NORM condition indicators are provided to aid in adjustment and
system trouble-shooting.
Out of stock
Specifications
| Nominal AC Voltage | 208/240VAC |
|---|---|
| Adjustment Range | 160-240VAC |
| Frequency | 60Hz |
| Power Consumption | 0.25W |
| Transient Protection | 2500V for 10ms |
| Repeat Accuracy | 0.1% of set point (fixed conditions) |
| Response Time | 0.05 seconds |
| Reset Time | 0.05 seconds |
| Reset Type | Automatic |
| Dead Band | 2% |
| Output Contacts | 1 - SPDT & 1 - SPST (N.O.) |
| Contact Rating | 5A at 115VAC resistive |
| Expected Relay Life (Mechanical) | 10 million operations |
| Expected Relay Life (Electrical) | 100,000 at rated load |
| Operating Temperature | -20° to 131° F |
| Humidity Tolerance | 97% w/o condensation |
| Enclosure Material | ABS plastic |
| Mounting | 8-pin socket (*order separately) |
| Agency Approvals | UL Recognized (U.S. & Canadian) |
| Required Socket Part Number | 51X120 |
| Feature | Detects Phase Loss, Low Voltage and Phase Reversal |
