EX257B
Categories: 257-Series, 3-Phase-MonitorsThe 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.
If Octopart does not currently display the Time Mark product you desire, please call us Toll-Free at (800) 862-2875 or use the Find a Distributor link on our website to find a distributor near you.
Additional Information
400 Hz Model | Yes |
---|---|
Automatic Reset | Yes |
Certifications | CSA and UL |
Contacts | SPDT |
Manual Reset | No |
Mount | 8-Pin |
Phase Sensing | Phase Reversal,Phase Loss |
Trip Delay | No |
Trip Restart | No |
Voltage Sensing | Under Voltage Protection |
Voltage Range | 380VAC,50 Hz |