YASKAWA V1000 Quick Start Manual page 222

C.3 Safe Disable Input Precautions
n
Installation Precautions
• To ensure the Safe Disable function appropriately fulfills the safety requirements of the
application, a thorough risk assessment for the safety system must be carried out.
• The drive must be installed in an enclosure with a protection degree of at least IP54 in order
to maintain ISO 13849-1, safety category 3 compliance.
• If the safety device and the drive are installed in separate cabinets, install the Safe Disable
wires in a manner preventing short circuits.
• 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 power supply
of the drive must be switched off.
• Consider the following when using PM motors: When the Safe Disable function is active,
a failure in two of the drive power devices can occur and current will continue to flow
through the motor winding. This failure will not produce torque in an induction motor,
however, when occurring in a PM motor, torque will be produced and cause an alignment
of the rotor magnets, which may cause the rotor to turn up to 180 degrees electrically. Ensure
that this possible failure mode is not safety-critical for the application.
• The wiring distance for the Safe Disable inputs should not exceed 30 m.
• The time from opening the Safe Disable input until the drive output is switched off is less
than 1 ms.
222 YASKAWA ELECTRIC TOEP C710606 47A YASKAWA AC Drive – V1000 Quick Start Guide