Chapter 2 Installation and Storage2-10 Revision June 2010increase to 120°C or higher (on condition that when the regeneration continuouslyoccurred). For safety reasons, forced air cooling is good way that can be used to reducethe temperature of the regenerative resistors. We also recommend the users to use theregenerative resistors with thermal switches. As for the load characteristics of theregenerative resistors, please check with the manufacturer.External Regenerative ResistorWhen using external regenerative resistor, connect it to P and C, and make sure the circuitbetween P and D is open. We recommend the users should use the external regenerativeresistor that the resistance value following the above table (Built-in Regenerative ResistorSpecifications). We ignore the dissipative power of IGBT (Insulated Gate Bipolar Transistor) inorder to let the users easily calculate the capacity of regenerative resistor. In the followingsections, we will describe Regenerative Power Calculation Method and Simple CalculationMethod for calculating the regenerative power capacity of external regenerative resistors.Regenerative Power Calculation Method(1) Without LoadWhen there is no external load torque, if the servo motor repeats operation, the returnedregenerative power generated when braking will transmitted into the capacitance of DCbus. After the capacitance voltage exceeds some high value, regenerative resistor candissipate the remained regenerative power. Use the table and procedure described belowto calculate the regenerative power.Servo Drive(kW) Servo Motor Rotor InertiaJ (× 10 -4kg.m2)Regenerative powerfrom empty load3000r/min to stopEo (joule)Max. regenerativepower ofcapacitanceEc(joule)0.1 ECMA-C20401
0.037 0.18 30.2 ECMA-C20602
0.177 0.87 40.4 ECMA-C20604
ECMA-C20804
0.2770.681.373.36 80.75 ECMA-C20807
1.13 5.59 141.0 ECMA-C21010
2.65 13.1 18LowInertia2.0 ECMA-C21020
4.45 22.0 210.4 ECMA-E21305
8.17 40.40 81.0 ECMA-E21310
8.41 41.59 181.5 ECMA-E21315
11.18 55.28 182.0 ECMA-E21320
ECMA-E21820
14.5934.6872.15171.50 21MediumInertia3.0 ECMA-E21830
54.95 271.73 28
