Mitsubishi Electric MR-J4W2-0303B6, Instruction Manual

Page: 359 / 588

15. USING A DIRECT DRIVE MOTOR
15 - 18
15.4 Characteristics
15.4.1 Overload protection characteristics
An electronic thermal relay is built in the servo amplifier to protect the servo amplifier, the direct drive motor,
and direct drive motor power wires from overloads.
[AL. 50 Overload 1] occurs if overload operation performed is above the electronic thermal protection curve
shown in fig. 15.2. [AL. 51 Overload 2] occurs if the maximum current is applied continuously for several
seconds due to machine collision, etc. Use the equipment on the left-side area of the continuous or broken
line in the graph.
For the system where the unbalanced torque occurs, such as a vertical axis system, it is recommended that
the unbalanced torque of the machine be kept at 70% or less of the motor's rated torque.
This servo amplifier has solid-state direct drive motor overload protection for each axis. (The direct drive
motor overload current (full load current) is set on the basis of 120% rated current of the servo amplifier.)
1000
100
10
1
0.1
0 50 150 200 250 300 100
Servo-lock
Oper
ation time [s]
(Note) Load ratio [%]
Operating
0 50 100 150 200 250 300 350
1000
100
10
1
Servo-lock
Operating
0.1
Operation time [s]
(Note) Load ratio [%]
TM-RFM002C20/TM-RFM004C20/TM-RFM006C20
TM-RFM006E20/TM-RFM012E20/TM-RFM018E20
TM-RFM012G20
TM-RFM040J10 TM-RG2M002C30
TM-RU2M002C30
TM-RG2M004E30
TM-RU2M004E30
TM-RG2M009G30
TM-RU2M009G30
Note. If operation that generates torque more than 100% of the rating is performed with an abnormally high frequency in a direct drive
motor stop status (servo-lock status) or in a 50 r/min or less low-speed operation status, the servo amplifier may malfunction
regardless of the electronic thermal relay protection.
Fig. 15.2 Electronic thermal protection characteristics