What principles should be followed in selecting switchgear for capacitor banks
Issuing time:2021-11-09 10:17
(1) the circuit breaker should be used to cut off capacitor current and not reignite.
(2) the rated current of the circuit breaker should be at least 1.43 times the rated current of the capacitor bank (1.3 times should be selected in the subject of the low-voltage electrician job certificate examination).
(3) The rated breaking current of the circuit breaker shall not be less than the effective value of the periodic component of the three-phase short-circuit current in the actual breaking time of the circuit breaker (the sum of the relay protection operation time and the inherent breaking time of the circuit breaker).
(4) The rated peak current of the circuit breaker shall not be less than the maximum short-circuit current, and not less than the peak charging inrush current when the capacitor bank is put in.
(5) For indoor low-voltage capacitor banks below 50 kW, iron shell switches should be used to control them; The low voltage capacitor banks above 50 KKW can be operated by automatic air switch or AC contactor according to the specific situation.