Mitsubishi Electric MELSERVO-J3W Series, Instruction Manual

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10. CHARACTERISTICS
10 - 1
10. CHARACTERISTICS
10.1 Overload protection characteristics
An electronic thermal relay is built in the servo amplifier to protect the servo motor, the servo amplifier and the
servo motor power lines from overloads. Overload 1 alarm (50. ) occurs if overload operation performed is
above the electronic thermal relay protection curve shown in any of Figs 10.1. 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.
When closely mounting MR-J3W-44B, operate the servo amplifier at 90 or smaller effective load ratio.
Servo amplifier MR-J3W series has solid-state servo motor overload protection. (The motor full load current is
115 rated current.)
(Note 1) Load ratio [ ]
0.1
100 200 300 0 50 150 250
1000
100
10
1
Operat
ion t
im
e [
s]
In servo lock
In operation
HF-MP053/13
HF-KP053/13
(Note 1, 2) Load ratio [ ]
1000
100
10
1
0.1
100 200 300 400 0
In servo lock
In operation
50 150 250 350
O
perat
io
n t
im
e [
s]
HF-MP23/43/73
HF-KP23/43/73
HF-SP51/81/52/102
HC-UP72
HC-LP52/102
HF-JP53/73/103
Note 1. 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.
2. The operation time at the load ratio of 300 to 400 applies when the maximum torque of HF-JP servo motor is increased to 400.
Fig. 10.1 Electronic thermal relay protection characteristics