B&R ACOPOSinverter P84, User Manual

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Integrated safety functions
ACOPOSinverter P84 User's Manual 2.10 349
3.3 Description
3.3.1 (PWR) Power removal (STO - Safe torque off)
The purpose of this function is to place the motor in a state without torque, where the motor coasts to a stop or
motor startup is prevented. This status is safety-relevant, since no torque is available to the motor. This function
is always assigned to logical input "PWR".
The status PWR (STO) can be activated via the inverter or with Automation Studio.
Frequency
Current
Frequency
PWR (STO) activation
t
PWR (STO) - Normative reference
The normative definition of function PWR (STO) can be found in § 4.2.2.2.2 of standard IEC 61800-5-2: "No voltage
is applied to the motor that can generate rotation (or movement in the case of a linear motor)". The PDS (SR)
(power frequency inverter system with safety-related function) provides the motor with no energy with which torque
(or, in the case of a linear motor, power) can be generated.
Note:
•
This safety function corresponds to an uncontrolled stop in accordance with stop category 0
of IEC 60204-1.
•
This safety function may be used where power removal is required to prevent an unexpected
startup.
•
In situations where external influences (e.g. dropping suspended loads) are present, additional
measures (e.g. mechanical brakes) may be required to eliminate any hazards.
•
Electronic measures and contactors are not sufficient to protect against electric shock, so ad-
ditional insulation measures may be required.