External Dynamic Brake; Mr-J3 Series - Mitsubishi Electric MELSERVO-J3 Series Handbook

Part 5: Review on Replacement of MR-J3-DU_ with MR-J4-DU_

7.6 External dynamic brake

CAUTION

7.6.1 MR-J3 series

The dynamic brake is designed to bring the servo motor to a sudden stop when a power failure occurs or the
protective circuit is activated. When using the
external dynamic brake, assign the dynamic brake interlock (DB) to any of CN3-9, CN3-13, and CN3-15 pins
in [Pr. PD07 to PD09].
Use an external dynamic brake for this drive unit. Failure to do so will cause an
accident because the servo motor does not stop immediately but coasts at an
alarm occurrence for which the servo motor does not decelerate to stop. Ensure
the safety in the entire equipment. For alarms for which the servo motor does not
decelerate to stop, refer to chapter 6.
The external dynamic brake cannot be used for compliance with SEMI-F47
standard. Do not assign DB. Doing so will cause the drive unit to become servo-
off when an instantaneous power failure occurs.
POINT
For drive units, EM2 has the same function as EM1 in the torque control mode.
Configure a sequence which switches off the magnetic contactor of the external
dynamic brake after (or as soon as) SON (Servo-on) has been turned off at a
power failure or a malfunction.
For the external braking time taken when the dynamic brake is operated, refer to
each servo amplifier instruction manual.
The external dynamic brake is rated for a short duration. Do not use it very
frequently.
The specifications of the input power supply for external dynamic brake are the
same as those of the converter unit control circuit power supply.
When an alarm, [AL. E6 Servo forced stop warning], or [AL. E7 Controller forced
stop warning] occurs, or the power is turned off, the external dynamic brake will
operate. Do not use external dynamic brake to stop in a normal operation as it is
the function to stop in emergency.
For a machine operating at the recommended load to motor inertia ratio or less,
the estimated number of usage times of the external dynamic brake is 1000
times while the machine decelerates from the rated speed to a stop once in 10
minutes.
Be sure to enable EM1 (Forced stop 1) after servo motor stops when using EM1
frequently in other than emergency.
Converter unit Drive unit
MR-J3-DU30K_
MR-J3-CR55K
MR-J3-DU37K_
MR-J3-DU30K_4
MR-J3-DU37K_4
MR-J3-CR55K4
MR-J3-DU45K_4
MR-J3-DU55K_4
Dynamic brake
DBU-37K
DBU-55K-4
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