YASKAWA V1000 Series Installation & Start-Up Manual page 429

installed in a short circuit proof way.
4. The Safe Disable function does not cut the power supply to the drive and does not provide electrical
isolation. Before any installation or maintenance work is done, the drives power supply must be
switched off.
5. When PM motors are used, the following must be considered:
Even if the HWBB function is active, although unlikely a failure in two of the drives power devices can
occur which means that current flows through the motor winding. In an induction motor no torque can
be produced by that. However, if this happens and a PM motor is connected a torque is produced
causing an alignment of the rotor magnets. The rotor may turn up to 180 deg electrically. It must be
ensured, that this possible failure mode is not safety critical for the application.
6. The time from opening the the Safe Disable input until the drive output is switched off is less than 1 ms.
YASKAWA ELECTRIC TOEP C710606 09B YASKAWA AC Drive V1000 Installation & Start-Up Manual
D.4 Safe Disable Input Precautions
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