KEB COMBIVERT F4-C Applications Manual

Also see for COMBIVERT F4-C: Instruction manual

Contents

3ANTRIEBSTECHNIK6 9 3KEB COMBIVERT F4-CName: Basis29.01.986ANTRIEBSTECHNIKSection PageDate© KEB Antriebstechnik, 1997All Rights reservedChapterFunctional DescriptionSpecial Functions6.9 SpecialFunctionsFig. 6.9.1 Principle of DC-Brake6.9.1 DC-Brake At DC-braking the motor is not decelerated by the ramp. The fast braking occursthrough DC voltage, which is given on the motor winding.Between the activation and the triggering of the DC-braking a time constant calledBase-Block-Time (bbL) of 150…1500 ms (depending on the motor size) is required.It serves for the protection of the power modules during the motor de-excitation time.The trigger for the DC-braking is adjusted with Pn.8. Corresponding to the adjustedmode a frequency can be adjusted with Pn.9, at which the DC-Brake engages.Pn.11determines the time of braking. With Pn.10 the maximum braking voltage is adjusted.For that the brake controllers are designed for a 1:1 dimensioning of inverter to motor,consequently the maximum braking voltage must be reduced in case of deviatingdimensioning in order to avoid an overheating of the motor. At large capacities themaximum braking voltage can lead to overcurrent errors (OC). In that case reducePn.10.The following section shall facilitate the adjustment and programming of specialfunctions.Pn.11 DC-Brake / TimeSet braking time= 0...100sActual braking time= Pn.11 · fist100 HzPn.8 DC-Braking/Aktivation0 DC-Braking not activated1 DC-Braking after attaining ru.3 = 0Hz andmissing setting of rotation: maximally forthe adjusted DC-braking time Pn.11(independent of actual frequency) or up tothe next setting of rotation.2 DC-Braking as soon as direction of rotationis missing (braking time depends on actualfrequency ru.3).3 DC-Braking as soon as direction of rotationchanges (braking time depends on actualfrequency ru.3).4 DC-Braking as soon as setting of rotationis missing and actual frequency falls belowthe adjusted level Pn.9 (braking timedepends on actual frequency ru.3).5 DC-Braking as soon as actualfrequencyfalls below the adjusted level Pn.9 (brakingtime depends on actual frequency ru.3).6 DC-Braking as soon as setpoint frequencyru.6 falls below the adjusted level Pn.9(braking time depends on ru.3)7 DC-Braking as soon as an inputprogrammed for DC-braking is active(di.3...di.10=4), braking time depends onactual frequency ru.3. Restart only afterdeactivating the input.8 DC-Braking for as long as an inputprogrammed for DC-braking is active(di.3...di.10=4).9 DC-Braking after enabling the modulation(direction of rotation + control release) forthe adjusted time Pn.11.ru.3 Actual frequencyPn.9 DC-Brake / Starting frequency0...409,5 Hz (default 4Hz)ru.6 Set frequencyPn.10 DC-Brake / max. voltage0...25,5% (default 25,5%)see function"Digital Inputs"di.3...di.10 = Value 3