Mitsubishi Electronics MR-J2S- B User Manual
11 - 1
11. CHARACTERISTICS
11. CHARACTERISTICS
11.1 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 (50) occurs if overload operation performed is above the electronic
thermal relay protection curve shown in any of Figs 11.1, Overload 2 alarm (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.
from overloads. Overload 1 alarm (50) occurs if overload operation performed is above the electronic
thermal relay protection curve shown in any of Figs 11.1, Overload 2 alarm (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
10
1
0.1
0
50
150
200
250
300
(Note) Load ratio [%]
Operat
ion t
im
e[
s]
100
During rotation
During servo lock
a. MR-J2S-10B to MR-J2S-100B
1000
100
10
1
0.1
0
50
150
200
250
300
(Note) Load ratio [%]
Operat
ion t
im
e[
s]
100
During rotation
During servo lock
b. MR-J2S-200B to MR-J2S-350B
0
50
100
150
200
250
300
1
10
100
1000
10000
(Note) Load ratio [%]
Ope
rat
ion t
im
e[
s]
During rotation
During servo lock
c. MR-J2S-500B MR-J2S-700B
10000
1000
100
10
1
0
100
200
300
Op
er
a
tio
n tim
e[s]
(Note) Load ratio [%]
During rotation
During servo lock
d. MR-J2S-11KB to MR-J2S-22KB
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.
electronic thermal relay protection is not activated.
Fig 11.1 Electronic thermal relay protection characteristics