Danfoss VLT FCD 303 Operating Instructions Manual

Also see for VLT FCD 303: Design guide

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Danfoss VLT FCD 303 Operating Instructions Manual Manual pdf 18 page image

VLT ® FCD Series■ Brake resistorNo. 81 (optionalfunction)82 (optionalfunction)Brake resistorterminalsR- R+The connection cable to the brake resistor mustbe screened/armoured. Connect the screen to themetal cabinet of the frequency converter and to themetal cabinet of the brake resistor by means ofcable clamps. Dimension the cross-section of thebrake cable to match the brake torque.See chapter Dynamic Braking in the Design GuideMG.90.FX.YY for dimensionering of brake resistors.NB!:Please note that voltages up to 850 VDC occur on the terminals.■ Control of mechanical brakeNo. 122 (optionalfunction)123(optionalfunction)MBR+ MBR- Mechanical brake(UDC=0.45 X MainsVoltage) Max 0.8 AIn lifting/lowering applications you need to be ableto control an electromagnetic brake. The brakeis controlled using the special mechanical brakecontrol/supply terminals 122/123.When the output frequency exceeds the brake cutout value set in par. 138, the brake is released if themotor current exceeds the preset value in parameter140. When stopping the brake is engaged whenthe output frequency is less than the brake engagingfrequency, which is set in par. 139.If the frequency converter is at alarm statusor in an overvoltage situation the mechanicalbrake is cut in immediately.If not using the special mechanical brake control/supplyterminals (122-123), select Mechanical brake controlin parameter 323 or 341 for applications withan electromagnetic brake.A relay output or digital output (terminal 46)can be used. See Connection of mechanicalbrake for further details.MG.04.B7.02 - VLT is a registered Danfoss trademark18