MITSUBISHI ELECTRIC Merservo MR-J2S- B - Manual (Page 152)

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.
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.
Fig 11.1 Electronic thermal relay protection characteristics