Sigma II User’s Manual Chapter 5: Parameter Settings and Functions5-83Parameter Settings and Functions5.6 Selecting a Regenerative ResistorWhen the servomotor operates in generator mode, power is returned to the servo amplifierside. This is called regenerative power. The regenerative power is absorbed by chargingthe smoothing capacitor, but when the capacitor’s charging limit is exceeded, theregenerative power is then reduced by the regenerative resistor.The servomotor is driven in regeneration (generator) mode in the following conditions:• While decelerating to a stop during acceleration/deceleration operation.• With a load on the vertical axis.• During continuous operation with the servomotor driven from the load side (negativeload).The capacity of the servo amplifier’s built-in regenerative resistor is designed forshort-term operation only, such as the deceleration stop period. Operation under anegative load is not possible.If the regenerative power exceeds the processing capacity of the servo amplifier, install anexternal regenerative resistor. The following table shows the specifications of the servoamplifier’s built-in resistor and the amount of regenerative power (average values) that itcan process.*1 The amount of regenerative power (average value) that can be processed is rated at 20% of thecapacity of the servo amplifier’s built-in regenerative resistor.*2 The values in parentheses are for the optional JUSP-RA04 Regenerative Resistor Unit.*3 The values in parentheses are for the optional JUSP-RA05 Regenerative Resistor Unit.*4 The values in parentheses are for the optional JUSP-RA18 Regenerative Resistor Unit.*5 The values in parentheses are for the optional JUSP-RA19 Regenerative Resistor Unit.When installing an external regenerative resistor, make sure that its resistance isequivalent to that of the servo amplifier’s built-in resistor. If combining multiple small-capacity regenerative resistors to increase the regenerative resistor capacity (W), selectresistors so that the resistance value, including error, equals or exceeds the minimumallowable resistance shown in the above table.Applicable Servo AmplifiersBuilt-in ResistorSpecificationsRegenerativePowerProcessed byBuilt-inResistor*1 (W)MinimumAllowableResistance(Ω)Resistance(Ω)Capacity(W)Single-phase, 100V SGDH-A3BE to -02BE — — — 40Single-phase200VSGDH-A3AE to -04AE — — — 40SGDH-08AE-S 50 60 12SGDH-15AE-S 25 140 28 20Three-phase200VSGDH-05AE to -10AE 50 60 12 40SGDH-15AE 30 70 14 20SGDH-20AE 25 140 28 12SGDH-30AE 12.5SGDH-50AE 8 280 56 8SGDH-60AE (6.25)*2 (880) *2 (180) *2 5.8SGDH-75AE to -1EAE (3.13) 3) (1760) 3) (350) 3) 2.9Three-phase400VSGDH-05DE to -15DE 108 70 14 73SGDH-20DE to -30DE 45 140 28 44SGDH-50DE 32 180 36 28SGDH-60DE to -75DE (18) 4) (880) 4) (180) 4) 18SGDH-1ADE to -1EDE (14.25)5) (1760) 5) (350) 5) 14.2
