Each Active Front End Unit Has The Pre-Charging Circuit - Vacon NX Active Front End User Manual

Active Front End (AFE)
4.15.2

Each Active Front End unit has the pre-charging circuit

Each Active Front End can have its own pre-charging circuit. Each unit controls its own pre-charging
and main contactor. See Figure 22. One control switch can be used, but if an Active Front End unit
needs to be controlled independently, separate switches are needed. With this the system is more
redundant than with a common pre-charging circuit. The circuit diagram for control, see Appendix
70 and Appendix 72.
Main Circuit
PE
Derating as a function
of ambient tempera-
ture
+LCL-U1
+AFE-U1
NXA xxxx x
Figure 22. Active Front End units parallel connection with own pre-charging circuits
24-hour support +358 (0)201 212 575 • Email: vacon@vacon.com
+LCL-U2
+AFE-U2
NXA xxxx x
vacon • 43
Ambient temperature, °C
Loadability, %
DC+
DC-
11166.emf
4