Active Front End (AFE) vacon • 4324-hour support +358 (0)201 212 575 • Email: vacon@vacon.com44.15.2 Each Active Front End unit has the pre-charging circuitEach Active Front End can have its own pre-charging circuit. Each unit controls its own pre-chargingand main contactor. See Figure 22. One control switch can be used, but if an Active Front End unitneeds to be controlled independently, separate switches are needed. With this the system is moreredundant than with a common pre-charging circuit. The circuit diagram for control, see Appendix70 and Appendix 72.Figure 22. Active Front End units parallel connection with own pre-charging circuitsPE+LCL-U1 +LCL-U211166.emf+AFE-U1NXA xxxx x +AFE-U2NXA xxxx xDC+DC-Main CircuitDouble InsulatedDouble InsulatedDouble InsulatedDouble InsulatedDerating as a functionof ambient tempera-tureAmbient temperature, °CLoadability, %
