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Chapter 1 Using the Robot Safely
4 Robot Safety Functions(1) Overload detection
This function detects an overload applied to the motor and shuts off the servo
power.
(2) Overheat detection
This detects an abnormal rise in the controller driver temperature and shuts
off the servo power.
If an overload or overheat error occurs, take the following measuring.
1. Insert a timer in the program.
2. Reduce the acceleration coefficient.
(3) Soft limits
Soft limits can be set on each axis to limit the working envelope in manual
operation after return-to-origin and during automatic operation. Note that
the working envelope is the area limited by soft limits.
(4) Mechanical stoppers
If the servo power is suddenly shut off during high-speed operation by emer-
gency stop or safety functions, these mechanical stoppers prevent the axis
from exceeding the movable range.
No mechanical stopper is provided on the R-axis.
Note that the movable range is the area limited by the mechanical stoppers.
(5) Z-axis (vertical axis) brake
An electromagnetic brake is installed on the Z-axis to prevent the Z-axis
from dropping when the servo power is shut off. This brake is working when
the controller power is OFF or if the Z-axis servo is OFF even when the
controller power is ON.
The Z-axis brake can be released by means of the programming unit or by a
command in the program when the controller power is ON.
WARNING
The Z-axis will drop when the brakes are released, creating a hazardous
situation.
• Press the emergency stop button and prop up the Z-axis with a support
stand, etc., before releasing the brake.
• Be careful not to let your body get caught between the Z-axis and in-
stallation base, etc., when releasing the brake to perform direct teach-
ing.