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11. CHARACTERISTICS
11. CHARACTERISTICS
11.1 Overload Protection Characteristics
An electronic thermal relay is built in the servo amplifier to protect the servo moto r and servo amplifier
from overloads. The operation characteristics of the electronic thermal relay are shown below. Overload 1
alarm (A. 50) occurs if overload operation performed is above the electronic thermal relay protection curve
shown below. Overload 2 alarm (A. 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.
If load is applied at stop (during servo lock), 70% of the rated torque must not be exceeded.
HC-AQ Series 1000
100
10
1
0.1
0 50 150 200 250 300
Load ratio [%]
100
During stop
During rotation
Operation time [s]
Fig 11.1 Electronic Thermal Relay Protection Characteristics