Chapter 5 Characteristics; Overload Protection Characteristics - Mitsubishi Electric MELSERVO-J5 User Manual

5
CHARACTERISTICS
For the characteristics of the linear servo motor and the direct drive motor, refer to the following.
Page 386 Characteristics
Page 420 Characteristics
5.1

Overload protection characteristics

Precautions
Servo amplifiers running firmware version A7 or later have improved overload protection for rotary servo motors. Overload
protection is triggered in a shorter period of time compared to servo amplifiers running version A6 or earlier so depending on
the operation pattern, overload warnings and alarms will easily occur. To prevent warnings or alarms from easily occurring, try
5
extending acceleration/deceleration times or revising the operation pattern. If any problems are caused by the changes made
to the characteristics of overload protection, contact your local sales representative.
Outline
An electronic thermal is built in the servo amplifier to protect the servo motor, servo amplifier and servo motor power wires
from overloads. In this section, overload protection characteristics refer to the overload protection characteristics of servo
amplifiers and servo motors.
[AL. 050 Overload 1] occurs if overload operation performed is above the electronic thermal protection curve shown below.
[AL. 051 Overload 2] occurs if the maximum current is applied continuously for several seconds due to machine collision, etc.
Use the equipment within the overload protection level indicated on the left side of the continuous or dotted lines in the
following graphs.
For machines where unbalanced torque occurs, such as a vertical axis system, the unbalanced torque should be kept at 70 %
or lower of the rated torque.
This servo amplifier has a servo motor overload protection function. (The servo motor overload current is set on the basis of
115 % rated current (full load current) of the servo amplifier.)
The servo amplifier may malfunction regardless of the electronic thermal protection if torque exceeding 100 % of the rated
torque is generated too frequently while the servo motor is stopped (servo-lock status) or being operated at low speeds of 50
r/min or less.
5 CHARACTERISTICS
119
5.1 Overload protection characteristics