MITSUBISHI ELECTRIC MELSERVO MR-J2S- A - Manual (Page 218)

12 - 1
12. CHARACTERISTICS
12. CHARACTERISTICS
12.1 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 12.1. 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
10
1
0.1
0 50 150 200 250 300
(Note) Load ratio [%]
O
perat
io
n t
im
e
[s
]
During rotation
During stop
100
a. MR-J2S-10A to MR-J2S-100A
1000
100
10
1
0.1
0 50 100 150 200 250 300
(Note) Load ratio [%]
O
perat
io
n t
im
e
[
s
]
During rotation
During stop
b. MR-J2S-200A to MR-J2S-350A
0 50 100 150 200 250 300
1
10
100
1000
10000
(Note) Load ratio [%]
Operat
io
n
t
im
e
[s
]
During rotation
During servo lock
c. MR-J2S-500A MR-J2S-700A
10000
1000
100
10
1
0 100 200 300
Ope
rat
ion t
im
e
[s
]
(Note) Load ratio [%]
During rotation
During servo lock
d. MR-J2S-11KA to MR-J2S-22KA
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 12.1 Electronic thermal relay protection characteristics