The Safe torque off function
Contents of this chapter
This chapter describes the Safe torque off (STO) function of the drive and gives instructions
for its use.
Description
WARNING!
In case of parallel-connected drives or dual-winding motors, the STO must be
activated on each drive to remove the torque from the motor.
The Safe torque off function can be used, for example, as the final actuator device of safety
circuits that stop the drive in case of danger (such as an emergency stop circuit). Another
typical application is a prevention of unexpected start-up function that enables short-time
maintenance operations like cleaning or work on non-electrical parts of the machinery without
switching off the power supply to the drive.
When activated, the Safe torque off function disables the control voltage of the power
semiconductors of the drive output stage (A, see the diagrams below), thus preventing the
drive from generating the torque required to rotate the motor. If the motor is running when
Safe torque off is activated, it coasts to a stop.
The Safe torque off function has a redundant architecture, that is, both channels must be
used in the safety function implementation. The safety data given in this manual is calculated
for redundant use, and does not apply if both channels are not used.
The Safe torque off function complies with these standards:
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The Safe torque off function 253
Summary of Contents for ACS880-37
Page 1: ... ABB INDUSTRIAL DRIVES ACS880 37 drives 45 400 kW 60 450 hp Hardware manual ...
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Page 196: ... 196 Maintenance ...
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Page 235: ...R8 IP22 UL Type 1 and IP42 UL Type 1 Filtered option B054 option E206 Dimension drawings 235 ...
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Page 238: ...R11 IP54 UL Type 12 option B055 238 Dimension drawings ...
Page 240: ...R11 IP54 UL Type 12 option B055 option C128 240 Dimension drawings ...
Page 241: ...R11 IP54 UL Type 12 option B055 option C129 Dimension drawings 241 ...
Page 242: ...R11 IP54 UL Type 12 option B055 options C129 H350 H352 242 Dimension drawings ...
Page 243: ...R11 IP22 UL Type 1 and IP42 UL Type 1 Filtered option B054 option D150 Dimension drawings 243 ...
Page 245: ...R11 IP22 UL Type 1 and IP42 UL Type 1 Filtered option B054 option E206 Dimension drawings 245 ...
Page 246: ...R11 IP22 UL Type 1 option E202 246 Dimension drawings ...
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