Active Front End (AFE) vacon • 49Local contacts: http://drives.danfoss.com/danfoss-drives/local-contacts/44.15.2 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 20. 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 Appendix74 and Appendix 76.Figure 20. 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 Insulated
