2 When star-shaped wiring is in color, the voltage on the capacitor is the phase voltage, and the phase ratio with root number 3 is 1 of the line voltage, and the reactive power output is directly proportional to the square of the capacitor voltage, that is, QC=U2C/XC, so the reactive power output of star-shaped wiring will be reduced by 1/3. In star connection, the short-circuit phase current is the geometric sum of the two-phase currents that are not short-circuited, and its value will not exceed 3 times of the rated current of the capacitor, while in triangle connection, the short-circuit current will exceed many times of the rated current of the capacitor, which is easy to cause the accident to expand. Therefore, considering all aspects of short circuit, it is more reasonable to use star connection.