Delta ASD-A3-0121, User Manual

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Installation ASDA-A3
2-18
Revision December, 2017
2
Example:
For a 400 W motor (ECM-A3L-CY0604RS1), and the torque of the external load is +70% of the
rated torque (1.27 N-m) with rotation speed up to 3000 rpm, the required external regenerative
resistance is:
2 × (0.7 × 1.27) × (
3000 × 2 × π
60
)
= 558 W
So, a regenerative resistor of 560 W and 40 Ω is needed.
2.9 The use of braking
A brake is usually used for motions in Z-axis direction because gravity causes the mechanism to
fall. A brake can prevent the mechanism from falling and greatly reduce the motor's resistance
output. The motor lifespan could be reduced due to resistance and excessive heat generation.
To avoid incorrect operation, the brake can be enabled only when the servo is switched off.
The servo drive controls the brake with DO. If DO.BRKR is set to off, it means the brake is not
operating and the motor is clamped. If DO.BRKR is set to on, it means the brake is operating and
the motor can run freely. You can use MBT1 (P1.042) and MBT2 (P1.043) to set the delay time.
Timing diagram of brake control:
ON
ON
OFF
OFF
OFF
OFF
SON
(DI)
BRKR
(DO)
Motor
speed
MBT1 (P1.042)
MBT2 (P1.043)
ZSPD (P1.038)
Output timing of the BRKR signal:
1.
When the servo drive is off and the time set for P1.043 is exceeded, but the motor speed is
still higher than the speed set for P1.038, DO.BRKR ends off (the motor is clamped).
2.
When the servo drive is off and the time set for P1.043 is not yet reached, but the motor
speed is already lower than the speed set for P1.038, DO.BRKR is off (the motor is
clamped).