Mitsubishi Electric Melservo-J3 Series MR-J3-B, Instruction Manual

Page: 398 / 802

13 - 1
13. CHARACTERISTICS
13. CHARACTERISTICS
13.1 Overload protection characteristics
An electronic thermal is built in the servo amplifier to protect the servo motor, servo amplifier and servo motor
power wires from overloads.
Overload 1 alarm (A50) occurs if overload operation performed is above the electronic thermal relay protection
curve shown in any of Figs 13.1. Overload 2 alarm (A51) 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. When you
mount the servo amplifier closely, make ambient temperature into 0 to 45°C
or use it with 75% or less of
effective load torque.
The MR-J3 series servo amplifiers have the servo motor overload protective function.
(It is set on the basis (full load current) of 115% of the servo amplifier.)
1000
100
10
1
0.1
100 200 300 350 0 50 150 250
O
pe
ra
tio
n
tim
e
[s
]
Servo-lock
Operation
(Note 1, 2) Load ratio [%]
MR-J3-10T(1)
1000
100
10
1
0.1
100 200 300 400 0 50 150 250 350
O
pe
ra
tio
n
tim
e
[s
]
Servo-lock
Operation
(Note 1, 2, 3) Load ratio [%]
MR-J3-20T(1) to MR-J3-40T(1)
MR-J3-60T(4) to MR-J3-100T(4)