10 - 2
10. CHARACTERISTICS
10. CHARACTERISTICS
10.1 Overload protection characteristics
An electronic thermal relay is built in the driver to protect the servo motor, driver and servo motor power lines
from overloads.
Overload 1 alarm (50. ) occurs if overload operation that exceeds the electronic thermal relay protection curve
shown in Figs 10.1. is performed. Overload 2 alarm (51. ) occurs if the maximum current flows continuously
for several seconds due to machine collision, etc. Keep the load ratio within the area in the left side of the solid
line or the dotted line.
It is recommended to use the machine which generates unbalanced torque, e.g. a vertical lift application, so
that the unbalanced torque is not more than 70% of the rated torque. When closely mounting the drivers,
operate them at the ambient temperature of 0
to 45
(32 to 113 ) or at 75% or smaller effective load
ratio.
The servo motor overload protective function is built in LECSA
□
-
□
series drivers. (115% of the driver rated
current is set as standard (full load current).)
Op
e
ra
tion
t
ime[
s
]
1000
100
10
1
0.1
0
50
150
200
250
300
100
During operation
During servo lock
Op
e
ra
tion
t
ime[
s
]
1000
100
10
1
0.1
0
50
150
200
250
300
During operation
During servo lock
100
(Note) Load ratio [%]
(Note) Load ratio [%]
LECSA2-S1
LECSA2-S3 LECSA2-S4
Note. If operation that generates torque equal to or higher than the rating is performed with an abnormally high frequency under servo
motor stop status (servo lock status) or in low-speed operation at 30r/min or less, the driver may malfunction even when the servo
system is used within the electric thermal protection area.
Fig 10.1 Electronic thermal relay protection characteristics
