EA180 Series Servo Drive Users Manual 2.6 Suggestions for circuit breakers and fuses If the servo drive is equipped with a residual current circuit breaker for leakage fault protection, please select a model with sensitivity current above 200mA and operation time above 0.1 second in order to prevent misoperation of the circuit breaker. Please use a quick-action fuse, and its rated current should be about 1.5 times the drive capacity. UL/CSA recognized fuses and circuit breakers are strongly recommended. 2.7 Selection of braking resistor When the output torque and rotation speed of the motor are in opposite directions, energy will be transmitted back from the load to the drive.
This energy will be injected into the capacitor of the bus to increase the voltage of the bus inside the drive. The amount of recharged energy depends on the inertia of the motor rotor and load. If the system inertia is small, the recharged energy may be absorbed by the capacitor inside the drive. If the system inertia is large and exceeds the amount of energy that the capacitor can absorb, the voltage may rise high, causing the drive to stop or even damage. Therefore, when the voltage rises to a certain level, the recharged energy must be consumed by a braking resistor.
Table 2-1 below lists the rotor inertia of commonly used SER series servo motors, the energy absorption capacity of capacitor inside EA180 servo drive, and the calculation formula of regenerative energy. Table 2-1 Rotor inertia and regenerative energy absorption capacity of capacitor of common SER/SES series servo motors EA180 series servo drives contain braking resistors inside, which are suitable for general load inertia. Table 2-2 shows the specifications of built-in brake resistors of EA180 series servo drives.
Table 2-2 Minimum resistance of built-in braking resistor and allowable minimum external resistance of EA180 servo drive 2.7.1 Built-in braking resistor 17 Rotor Regenerative energy from Maximum regenerative inertia rated speed to 0 with Drive model Motor energy capacity of capacitor J( 104kg m2) no-load Ec (Joule) Eo (Joule) EA180□-0R9-1□ SES04-005-30-2□AY 0.02 0.1 9.5 EA180□-1R6-1□ SES04-0R1-30-2□AY 0.04 0.2 9.5 SER06-0R2-30-2□AY 0.18 0.89 9.5 EA180□-2R5-1□ SER06-0R4-30-2□AY 0.3 1.48 19 EA180□-4R8-2□ SER08-0R7-30-2□AY 1.01 4.99 20.2 EA180□-6R2-2□ SER13-1R0-10-2□BY 8.71 19.1 20.2 EA180□-011-2□ SER13-1R5-20-2□BY 12.08 26.5 45.7 EA180□-5R6-3□ SER13-1R5-20-3□BY 12.08 26.5 31.4 EA180□-8R5-3□ SER13-2R0-20-3□BY 17.14 37.67 51.7 EA180□-013-3□ SER13-3R0-20-3□BY 25.58 56.22 51.7 EA180□-017-3□ SES18-4R4-15-3FBY 67.5 83.45 110.7 EA180□-022-3□ SES18-5R5-15-3FBY 89 110.0 110.7 EA180□-028-3□ SES18-7R5-15-3FBY 125 154.53 138.4 Eo j.v2/182( Joule) Calculation formula of regenerative energy:
v: rpm, generally the rated speed of the motor The rotor inertia of a servo motor with brake and that of a servo motor without brake is slightly different, which can be regarded as the same. Built-in braking resistor specifications Energy handling capacity Allowable minimum Drive model Resistance (P8-10) Capacity (P8-11) of built-in braking resistor external resistance EA180-0R9-1□ N/A N/A N/A 50Ω EA180-1R6-1□ N/A N/A N/A 50Ω EA180-2R5-1□ N/A N/A N/A 50Ω EA180-4R8-2□ 50Ω 100W 50W 50Ω EA180-6R2-2□ 50Ω 100W 50W 50Ω EA180-011-2□ 50Ω 100W 50W 40Ω EA180-5R6-3□ 50Ω 100W 50W 50Ω EA180-8R5-3□ 50Ω 100W 50W 50Ω