3.10 Braking ResistorDynamic braking (DB) helps bring the motor to a smooth and rapid stop when working with high inertia loads. Regenerationoccurs as the drive lowers the motor frequency with high inertia. When the regeneration flows back into the DC bus capacitors,an overvoltage situation occurs. A braking resistor prevents these overvoltage faults.NOTICE: Do not allow unqualified personnel to use the product. Failure to comply could result in damage to the drive or braking circuit.Carefully review the braking resistor instruction manual when connecting a braking option to the drive.Note: The braking circuit must be sized properly in order to dissipate the power required to decelerate the load in the desired time. Ensure thatthe braking circuit can dissipate the energy for the set deceleration time prior to running the drive.NOTICE: Use a thermal overload relay or over-temperature contact to interrupt input power to the drive if the braking resistor overheats. Inthe event of a possible thermal overload, the relay triggers the input contactor and prevents the braking resistor from burning up.u InstallationWARNING! Fire Hazard. The braking resistor connection terminals are B1 and B2. Do not connect a braking resistor directly to any otherterminals. Improper wiring connections could result in death or serious injury by fire. Failure to comply may result in damage to the brakingcircuit or drive.NOTICE: Connect braking resistors to the drive as shown in the I/O wiring examples. Improperly wiring braking circuits could result in damageto the drive or equipment.n Installation Procedure1. Disconnect all electrical power to the drive and wait at least one minute before servicing the drive and any connectedcomponents.2. Remove drive front cover.3. Use a voltmeter to verify that voltage is disconnected from incoming power terminals and that the DC bus no longerholds a charge.PowersupplyThermalrelayMotorDriveBraking resistorThermal relay switch forexternal braking resistorFault contactMCSASASAMCONMCOFFTHRXTHRXTRXMCTRXMA MCR/L1 B1 B2S/L2T/L3U/T1V/T2W/T3MCCBFigure 3.20 Connecting a Braking Resistor4. Follow manufacturer instructions to connect the resistor unit to the drive using proper wire gauge according to localelectrical codes.Power leads for the remote mount resistors generate high levels of electrical noise; group these signal leadsseparately.5. Mount the resistor unit on a noncombustible surface. Maintain minimum side and top clearances according to resistormanufacturer instructions.WARNING! Fire Hazard. Do not use improper combustible materials. Failure to comply could result in death or serious injury byfire. Attach the drive or braking resistors to metal or other noncombustible material.6. Reinstall drive covers and resistor covers, if provided.7. Set parameter L3-04 = “0” to disable stall prevention during deceleration.Set parameter L8-01 to “1” to enable overheat protection when using a heatsink-mounted braking resistor option.Set L8-01 = “0” for other braking resistor types.3.10 Braking Resistor50 YASKAWA ELECTRIC SIEP C710606 31B YASKAWA AC Drive – J1000 Technical Manualhttp://nicontrols.com
