Delta C2000 Series User Manual page 88

AC Input Reactor
Installing AC reactor in the input side of AC motor drive can increase
factor, reduce input current, increase system capacity and reduce interference generated from motor
drive. In addition, to suppress the momentary voltage surge or abnormal current spike is also one of its
features. For example, when the capacity of main power is higher than 500 kVA, or switching to capacity
bank, the momentary voltage and current spike may damage motor drive's internal circuit. Therefore,
installing AC reactor in the input side of AC motor drive can
drive.
AC input reactor is installed serially between the mains power and three phases input side of motor
drive, which is shown as below:
Power inputs
AC Output reactor
Because motor drive control output voltage and frequency by PWM signals driving power
transistors switching, the voltage rapid rise and fall (dv/dt) frpm switching will lead to voltage uneven
distribution inside the motor and cause insulation deterioration, bearing currents, and
electromagnetic interference. Especially when there is longer cable length connected between motor
drive and motor, the damping will lead to
poor to enlarge the voltage reflection. This phenomenon will generate twice input voltage in motor
side, which will easily make motor voltage overshoot to damage insulation.
Chapter 7 Optional Accessories
AC reac tor
(input s ide)
Wiring of AC input reactor
high frequency resonator, and make
7-7
line impedance, improve power
suppress the surge to protect the AC motor
impedance matching
M