SWITCHING OF CAPACITOR BANKS

Switching of single capacitors, max. capacitive load at 400 V, 120 switching cycles per hour [kVAr]

Contactor	V85F	V105F	V140F	V170F	V205F	V250F	VH250DO	VH440	VD630
[kVAr]	50	60	70	80	100	120	170	220	320

It is highly recommended to align the appropriate fuses as well as the 5 μH-reactors (e. g. 5 windings of conductor at 400 mm diameter) to all poles, in order to reduce the risk of contact welding.

Extraordinarily high inrush current peaks occur in the utilization category AC-6b, making it possible for the contacts to weld by switching the capacitor bank. That is why the special contactors type C17C.10C, C32.11C, C65.11C and C80.11C switch in two steps. At first, the auxiliary contacts connect the capacitor with the mains through wire resistors and then pre-charge the capacitor. The main contacts close and consecutively short-circuit the ballast resistors mentioned above. Thereafter the auxiliary contacts return to their open position. The capacitor must be connected to the main pole terminals and must be equipped with discharge resistors. Usage of the capacitors in the bank should be done in an appropriate sequence, so that the voltage remaining on the capacitor being connected to the mains does not exceed 10 % of the mains voltage. Contactors include a special auxiliary PK30C contact unit. The enclosed wire resistors must be connected to the contactor terminals according to the wiring diagram. The terminal screws must be tightened properly!

Aligning of contactors for switching of capacitor banks in power factor compensating assemblies

Maximum reactive power of the capacitive load in the AC-6b [kVAr]

Contactor type	C12.10C		C17.10C		C25.11C		C32.11C		C50.11C		C65.11C		C80.11C
ambient temperature [°C]	<55	<70	<55	<70	<55	<70	<55	<70	<55	<70	<55	<70	<55	<70
at 220..230 V	7	6,2	8	7	10	10	15	15	25	25	30	25	35	30
at 380..400 V	10	10	12,5	11	17	17	25	25	40	40	50	45	60	50
at 500 V	13	13	15	12,5	20	20	30	30	50	50	60	55	70	60