Chordn’s three-phase monitoring relays HMPB7 series are mainly used to monitor the phase sequence, phase loss and over-undervoltage of power supply system. The width of these monitoring relays is 35.5mm and standard 35mm DIN rail mounting is adapted. There are three indicators on the relay panel to indicate the state of power, output and alarm, and three knobs to set the range of over-undervoltage and alarm delay.
These relays can monitor not only the voltage between phases, but also the voltage between phases and lines.
Voltage measurement range between phases: 208-480VAC
Voltage measurement range between phases and neutral : 120-277V
Monitoring function: phase sequence, phase loss, over-undervoltage
Indicators: Green LED, Yellow LED, Red LED
Overvoltage setting range( middle knob): +2% - +22%
Undervoltage setting range( up knob): -2% - -22%
Setting range of alarm delay(down knob): 0.1-30S
Setting range of power on delay: 1±0.5S / 6±0.5S
It is widely used in the relay protection of three-phase AC power supply and its load, such as high-power motor or transformer, etc. It can protect the motor or transformer from damage. It‘s also a solution for industrial equipment to be protected in the central air conditioning system, power system and other industries.