Technical Manual for EA350 Analog Pulse Type Servo Driver V101 2.6 Suggestions regarding circuit breaker and fuse If the driver is provided with a residual-current circuit breaker, to prevent malfunction of the circuit breaker, do select a model with the induced current of above 200mA and the actuation time of above 0.1s. For fuse, a fast-acting fuse shall be used, and its rated current shall be around 1.5 times the driver capacity. It is highly recommended: to use a UL/CSA-accepted fuse and circuit breaker. 2.7 Braking resistor selection When the motor has an output torque in opposite direction of its rotating speed, energy will be transferred from the load end back to the driver.
The energy will be charged into the bus capacitor to increase the bus voltage inside the driver; the amount of energy so charged depends on the motor rotor and the load inertia. If the system has low inertia, the energy transferred back may be fully absorbed by the capacitor inside of the driver; if the system has high inertia and the energy transferred back exceeds the absorbing capacity of the capacitor, excessive rise of the voltage may cause shutdown or even damage of the driver. For this reason, when the voltage rises to a certain value, the energy transferred back needs to be consumed by a braking resistor.
Table 2-1 below gives rotor inertia of common servo motors and absorbing capacity of the capacitor inside the EA350 driver, as well as the calculating formula of the recoverable energy. Table 2-1 Rotor inertia of common servo motors and recoverable energy-absorbing capacity of their capacitors 2.7.1 Built-in braking resistor Drivers of certain specifications under the EA350 series contain an internal braking resistor, applicable to circumstances of average load inertia. Table 2-2 shows specifications of the built-in braking resistor for EA350 series.
Table 2-2 Built-in braking resistor of EA350 driver and the minimum allowable resistance of an external braking resistor 18 Motor Maximum amount of Recoverable energy from the Rotor inertia recoverable energy to be Driver model rated speed without load to stop J (×10-4 kg·m2 ) absorbed by the capacitor Eo (J) Ec (J) EA350-0R9-1B SES04-005-30-2□AY 0.02 0.1 9.5 EA350-1R6-1B SES04-0R1-30-2□AY 0.04 0.2 9.5 SES06-0R2-30-2□BY 0.29 1.43 9.5 EA350-2R5-1B SES06-0R4-30-2□BY 0.58 2.87 19 EA350-4R8-2B SES08-0R7-30-2□BY 1.56 7.71 20.2 EA350-6R2-2B SER13-1R0-20-2□BY 8.71 19.1 24 EA350-011-2B SES13-0R8-15-2FBY 13.95 17.25 45.7 EA350-5R6-3B SES13-1R3-15-3FBY 19.95 24.66 31.4 EA350-8R5-3B SES13-1R8-15-3FBY 26.1 32.27 51.7 EA350-013-3B SES18-2R9-15-3FBY 46.0 56.87 51.7 EA350-017-3B SES18-4R4-15-3FBY 67.5 83.45 110.7 EA350-022-3B SES18-5R5-15-3FBY 89 110.0 110.7 EA350-028-3B SES18-7R5-15-3FBY 125 154.53 138.4 EA350-038-3B SEC23-015-15-3FBY 380 469.78 207.6 EA350-052-3B SEC23-022-15-3FBY 500 618.13 276.8 EA350-062-3B SEC23-029-15-3FBY 620 766.48 276.8 Calculation formula for recoverable energy:
Eo= J·v2 /182(joules) ; v: rpm, generally referring to the rated speed of the motor A servo motor with holding brake may be deemed to have the same rotor inertia as a servo motor without brake due to negligible difference in the rotor inertia.
Driver model Specification of the built-in braking resistor Recovering capacity of the built-in Allowable minimum resistance of Resistance (P8-10) Capacity (P8-11) braking resistor external braking resistor EA350-0R9-1B None None None 50Ω EA350-1R6-1B None None None 50Ω EA350-2R5-1B None None None 50Ω EA350-4R8-2B 50Ω 100W 50W 40Ω EA350-6R2-2B 50Ω 100W 50W 40Ω EA350-011-2B 50Ω 100W 50W 40Ω EA350-5R6-3B 50Ω 100W 50W 50Ω EA350-8R5-3B 50Ω 100W 50W 50Ω EA350-013-3B 50Ω 100W 50W 45Ω EA350-017-3B None None None 30Ω EA350-022-3B None None None 30Ω EA350-028-3B None None None 25Ω EA350-038-3B None None None 10Ω EA350-052-3B None None None 10Ω EA350-062-3B None None None 10Ω