Allen-Bradley PowerFlex 7000 Series, Руководство пользователя

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Rockwell Automation Publication 7000-UM203C-EN-P - September 2018 7
Chapter
1
General Description
The Safe Torque Off option is intended to be applied as a component in a
safety control system. Components in the system must be chosen and applied
appropriately to achieve the desired level of operational safety.
What Is the PowerFlex 7000
Drive Safe Torque Off Option? The PowerFlex™ 7000 Drive Safe Torque Off option:
• Is designed to help safely remove power from the gate firing circuits of
the drive’s power devices (SGCTs). This helps prevent the drive’s power
devices from switching in the pattern necessary to generate AC power to
the motor.
• Satisfies the STO definition in EN 61800-5-2:2007.
• Can be used in combination with other safety devices to satisfy the
requirements of IEC 61508, EN 61800-5-2 SIL 3, ISO 13849-1 PLe,
and Cat. 3 for Safe Torque Off (STO).
IMPORTANT This option is suitable for performing mechanical work on the drive system
or affected area of a machine only. It does not provide electrical safety.
This option should not be used as a control for starting and/or stopping the
drive.
ATTENTION: Electrical Shock Hazard. Verify that all sources of AC and DC
power are de-energized and locked out or tagged out in accordance with the
requirements of ANSI/NFPA 70E, Part II.
ATTENTION: In safe-off mode, hazardous voltages may still be present at the
motor. To avoid an electric shock hazard, disconnect power to the motor and
verify that the voltage is zero before performing any work on the motor.
ATTENTION: There is a residual risk associated with four or more failures of
SCGTs within the drive that would cause torque to be developed even when
the PowerFlex 7000 Drive Safe Torque Option has controlled the drive outputs
to the off state. In this case, the drive may provide energy until the published
response time of 1000 ms has expired.
ATTENTION: Removal of power generation from the drive to the motor does
not ensure the motor will not rotate. Mechanical braking may be necessary in
order to prevent motor rotation. In the absence of motor braking, the motor
may continue to rotate or may start to rotate based on the inertia of the load,
stored energy in the load, or external forces.