Chapter 4. Technical features introduction

**[[Note:]]** [[Under 3P3W wiring mode, phase voltage, active power, reactive power, apparent power and power factor are meaningless for each phase]]**[[.]]**

[[PMAC770H can be used as direct connect when the measured phase voltage is lower than 398V or line voltage is lower than 690V, it shall work with PT when input voltage is larger than above value. To keep the meter reflect accurate measuring, please pay attention to the linearity and accuracy of the PT when wiring.]] [[The overload capacity for voltage measuring by PMAC770H is 120%, the rated max measuring range is 690KV, the wiring mode of voltage measuring can be set over the panel or Modbus register, both 3P4W and 3P3W methods are supported for low voltage and high voltage situation.]] **[[Note:]]** [[1)     ]]**[[Please clear the electrical energy after changing the wiring method if any.]]** [[2)     ]]**[[PT ratio range is 1.00\~6900.00]]**

[[PMAC770H shall work with external CT for current measuring, and the secondly value of the CT shall be 5A to connect to PMAC770H, please avoid open circuit when doing CT wiring, as this may damage the device, most importantly this may bring danger to installation and maintenance people]] [[The overload capacity for current measuring by PMAC770H is 120%, the rated max measuring range is 50000A, the CT ratio range is 1.00\~10000.00.]]

[[PMAC770H supports measuring each phase active power (Pa, Pb, Pc) and total active power, single phase max measuring range is 34500MW, three phase max measuring range is 103500MW.]]

[[PMAC770H supports measuring each phase reactive power(Qa, Qb, Qc) and total reactive power, single phase max measuring range is 34500MVar, three phase max measuring range is 103500MVar.]] **[[Note:]]** **[[1)     Active and reactive power are signed values]]** **[[2)     Please pay attention to the phase sequence correspondence between voltage and current when wiring, as this may impact the accuracy of power calculating.]]** **[[3)     Please pay attention to the wiring of CT homonymous ends, wrong wiring may bring a measured negative value for power]]**

[[PMAC770H supports measuring each phase apparent power(Sa, Sb, Sc) and total apparent power, single phase max measuring range is 34500MVA, three phase max measuring range is 103500MVA.]]

[[PMAC770H supports measuring each phase and total power factor, and the measure range is -1.000\~+1.000.]]

[[The frequency measuring range of PMAC770H is 36\~65Hz, the measuring channel is different under different wiring mode. Under 3P3W wiring mode, PMAC770H takes frequency sample from line AB as default, if line AB is phase loss then takes from line CA, if both line AB and line CA are loss then the value will be 0. Under other wiring mode, PMAC770H will take frequency sample from phase channel (A/B/C).]]