Characteristics; Overload Protection Characteristics - Mitsubishi Electric MELSERVO-J2-Super Series Supplementary Instructions Manual

5. CHARACTERISTICS

5. CHARACTERISTICS

5.1 Overload protection characteristics

An electronic thermal relay is built in the servo amplifier to protect the servo motor and servo amplifier
from overloads. Overload 1 alarm (AL.50) occurs if overload operation performed is above the electronic
thermal relay protection curve shown in any of Figs 5.1. Overload 2 alarm (AL.51) occurs if the maximum
current flew continuously for several seconds due to machine collision, etc. Use the equipment on the left-
hand side area of the continuous or broken line in the graph.
In a machine like the one for vertical lift application where unbalanced torque will be produced, it is
recommended to use the machine so that the unbalanced torque is 70% or less of the rated torque.
1000
100
During stop
10
1
0.1
0 50 100
(Note) Load ratio [%]
a. MR-J2S-60A4/B4 MR-J2S-100A4/B4
10000
1000
During servo lock
100
10
1
0 50 100
(Note) Load ratio [%]
c. MR-J2S-500A4/B4 MR-J2S-700A4/B4
Note. If operation that generates torque more than 100% of the rating is performed with an abnormally high frequency in a servo motor stop
status (servo lock status) or in a 30r/min or less low-speed operation status, the servo amplifier may fail even when the electronic
thermal relay protection is not activated.
During rotation
150 200 250
During rotation
150 200 250
Fig 5.1 Electronic thermal relay protection characteristics
1000
100
10
1
0.1
0 50
300
b. MR-J2S-200A4/B4 MR-J2S-350A4/B4
10000
1000
100
During servo lock
10
1
300 0
d. MR-J2S-11KA4/B4 to MR-J2S-22KA4/B4
5 - 1
During rotation
During stop
100 150 200
(Note) Load ratio [%]
During rotation
100 200
(Note) Load ratio [%]
250 300
300