Capacitor Duty Contactors KC12 - KC60
During the exact moment of switching,a capacitor effectively appears as short circuit.The magnitude of capacitor in-rush or charging current will depend upon value of AC Voltage level at instant of switching,together with impedence of feeders cable & supply transformers.
In case of individual capacitor loads,charging current peaks of upto 30 times the rated capacitor current can occur.Whereas,tor multi-stage capacitor ,the in-rush current greater than 180 times the rated capacitor current can occur.
Such large-current can flow through contactor since initial in-rush current is taken from both mains-supply & capacitor already connected.As in-rush current of such high magnitude is undesirable &likely to weld main contacts of Standard Duty Contactors.
Operating Principle Kc ’s new Capacitor Duty Contactors are specially designed to meet Capacitor Duty applications.Contactors are fitted with block of three early make auxiliary contacts in series with quick discharge damping six resistors -2 per phase to limit peak current to value within Contactor making capacity such that normal rated capacitor curent is carried by main contacts which,after closing,effectively bypass the resistors.
Product range Contactor 3p,415 V rating 10 KVAR thru 60 KVAR,available in eight ratings, conforming to IEC-70 and 831.