PHASE PROTECTION RELAY เฟสโพรเทคชั่น 380V W-OP4 WIP W-OP4
3Ø Under, Over and Voltage unbalance with Selectable Voltage
The W-OP4 Phase Protection Relay is a digital electronic instrument designed
for AC voltage monitoring and protection in 3 phase 4 wire and 3 phase 3 wire system.
Used in application such as main failure, phase sequence, phase unbalance,
under and over voltage.