8.7 Additional Connections8.7.1 DC Bus ConnectionThe DC bus terminal is used for DC back-up, with the intermediate circuit being supplied from an external source.Terminal numbers used: 88, 89Please contact Danfoss if you require further information.8.7.2 Load SharingTerminal No. Function88, 89 LoadsharingThe connection cable must be screened and the max. length from the frequency converter to the DC bar is limited to 25 metres (82 feet).Load sharing enables linking of the DC intermediate circuits of several frequency converters.Please note that voltages up to 1099 VDC may occur on the terminals.Load Sharing calls for extra equipment and safety considerations. For further information, see load sharing Instructions MI.50.NX.YY.Please note that mains disconnect may not isolate the frequency converter due to DC link connection8.7.3 Installation of Brake CableThe connection cable to the brake resistor must be screened and the max. length from the frequency converter to the DC bar is limited to 25 metres (82feet).1. Connect the screen by means of cable clamps to the conductiveback plate on the frequency converter and to the metal cabinetof the brake resistor.2. Size the brake cable cross-section to match the brake torque.No. Function81, 82 Brake resistor terminalsSee Brake instructions, MI.90.FX.YY and MI.50.SX.YY for more information about safe installation.NB!If a short circuit in the brake IGBT occurs, prevent power dissipation in the brake resistor by using a mains switch or contactor todisconnect the mains for the frequency converter. Only the frequency converter shall control the contactor.Please note that voltages up to 1099 VDC, depending on the supply voltage, may occur on the terminals.8 Electrical Installation FC 300 Design Guide186 MG.33.BC.02 - VLT® is a registered Danfoss trademark8
