YASKAWA CIPR-GA50C series Technical Manual page 204

5.6 Safe Disable Input
Keypad Display
If the two input channels are OFF (Open), the keypad will flash STo [Safe Torque OFF].
If there is damage to the Safe disable circuit or the drive, the keypad will flash SToF [Safe Torque OFF
Hardware] when one input channel is OFF (Open), and the other is ON (Short circuit). When you use the Safe
disable circuit correctly, the keypad will not show SToF.
If there is damage to the drive, the keypad will show SCF [Safety Circuit Fault] when the drive detects a fault in
the Safe disable circuit. Refer to the chapter on Troubleshooting for more information.
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Validating the Safe Disable Function
After you replace parts or do maintenance on the drive, complete all necessary wiring to start the drive, then
follow these steps to test the Safe Disable input. Keep a record of the test results.
1. When the two input channels are OFF (Open), make sure that the keypad flashes STo [Safe Torque OFF], and
make sure that the motor is not running.
2. Monitor the ON/OFF status of the input channels and make sure that MFDO set to the EDM function operates
as shown in Table 5.24.
If one or more of the these items are true, the ON/OFF status of the MFDO may not display correctly on the
keypad.
• Incorrect parameter settings.
• A problem with an external device.
• The external wiring has a short circuit or is disconnected.
• There is damage to the device.
Find the cause and repair the problem to correctly display the status.
3. Make sure that the EDM signal operates during usual operation as shown in
204
Table 5.24.
YASKAWA SIEPC71061753A GA500 Technical Manual