Allen-Bradley Kinetix 350, Руководство пользователя

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102 Rockwell Automation Publication 2097-UM002D-EN-P - April 2017
Chapter 6 Kinetix 350 Drive Safe Torque-off Feature
Safety Category 3 Requirements
Safety-related parts are designed with these attributes:
• A single fault in any of these parts does not lead to the loss of the safety
function
• A single fault is detected whenever reasonably practicable
• Accumulation of undetected faults can lead to the loss of the safety
function.
Stop Category Definition
Stop category 0 is achieved with immediate removal of power to the actuator.
Performance Level and Safety Integrity Level (SIL) CL2
For safety-related control systems, Performance Level (PL), according to
EN ISO 13849-1, and SIL levels, according to EN 61508 and EN 62061,
include a rating of the systems ability to perform its safety functions. All safety-
related components of the control system must be included in both a risk
assessment and the determination of the achieved levels.
See the EN ISO 13849-1, EN 61508, and EN 62061 standards for complete
information on requirements for PL and SIL determination.
Description of Operation The safe torque-off feature provides a method, with sufficiently low probability
of failure on demand, to force the power-transistor control signals to a disabled
state. When disabled, or any time power is removed from the safety enable
inputs, all drives output-power transistors are released from the ON state,
effectively removing motive power generated by the drive. This results in a
condition where the motor is in a coasting condition (stop category 0).
Disabling the power transistor output does not provide mechanical isolation of
the electrical output, which can be required for some applications.
Under normal drive operation, the safe torque-off switches are energized. If
either of the safety enable inputs are de-energized, the gate control circuit is
disabled. To meet EN ISO 13849-1 (PLd) both safety channels must be used
and monitored.
IMPORTANT In the event of drive or control failure, the most likely stop category is
category 0. When designing the machine application, consider timing and
distance for a coast to stop. For more information regarding stop categories,
refer to EN 60204-1.