Vacon NX Active Front End User Manual

Contents

5vacon • 64 InstallationTel. +358 (0) 201 2121 • Fax +358 (0)201 212 2055.3 Power connection5.3.1 AC connectionThe 3-phase input is connected to the input terminals of the LCL filter (L1, L2 and L3). The outputterminals of the LCL filter (U, V and W) are connected to the input terminals of the AFE unit (U, Vand W), Figure 8. The AC input of the AFE input group must be protected against short circuit. Thefuses suitable for protection are shown in Chapter 4.11. A circuit breaker can also be used forprotection, see Chapter 4.12. The best short-circuit protection is achieved by using fuses. Theshort-circuit protection must be on the input side when seen from the LCL filter, Figure 8.A cable or busbar designed for the purpose must be used to make the connection. The connectionmust be dimensioned according to the nominal current rating of the Active Front End unit. Thenecessary overloading allowance must also be used. The connection must also have the sameshort-circuit capacity as the whole system. The connecting cable or busbar may be of copper oraluminium. When aluminium is used, steps must be taken to prevent corrosion. The dimensions ofthe terminals in the unit are indicated in Appendix 82 and their locations are shown in Appendix 73,Appendix 74 and Appendix 75. Locations of terminals in the LCL filter are shown in Appendix 76 andAppendix 77.5.3.2 DC connectionThe DC connection of the Active Front End unit is connected to the terminals at the top. Theterminals are marked as B+ for connection to DC+ and B- for connection to DC-. The DC connectionmust be protected using DC fuses, see Chapter 4.11. The terminal dimensions are shown inAppendix 82.5.3.3 LCL filter Fan power supplyTwo types of power supplies are available for the LCL filter cooling fan. The cooling fan can besupplied from an external power supply or an integrated DC/DC power supply.5.3.3.1 LCL filter with integrated DC/DC power supply for fanThe DC/DC power supply is integrated in the structure of the LCL filter, Figure 44 and Figure 45.The integrated DC/DC power supply takes its input voltage from the intermediate circuit,Appendix 79. The input of the DC/DC power supply must be protected against short circuit using DCfuses type Ferraz Shawmut ATQ8 (8 A) if the length of the supply cable does not exceed 2 m. Thefuses can be installed in holders type Ferraz Shawmut US102I (2-pole), to allow the easydisconnection of the DC/DC power supply from the supply. If the length of the supply cable exceeds2 m, fuses type Ferraz Shawmut D100gRB008VI (8 A) must be used. The fuses should be installedin holders.The high DC voltage must be taken into account when wiring the supply; suitable cables/leads mustbe used.The DC/DC power supply is monitored and controlled by the Active Front End unit. The DC/DC powersupply connections are shown in Figures 44 - 45 and Appendix 79 and Appendix 80.The control connection has to be taken from the Active Front End unit. The control cable has to beconnected to the terminal X51 on the LCL filter, see Figure 44 and Figure 45. The control cable hasto be connected to the terminal X3 on the Active Front End unit, see Figure 47. The terminal X3 canbe found under the black cover. In the FI13, the terminal X3 is located in the left-most unit. Thedelivery includes the cable for the control connection. The length of the standard cable is 1,6 m.The over-temperature protection can be wired directly to the control unit or to the DC/DC powersupply. The over-temperature protection must be connected to protect the filter for protect thefilter in case of over-temperature.NOTE! By default, the over-temperature protection is not activated. If it is not activated, the LCL canbe damaged in case of over-temperature.