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Lab 7: Demonstrating the Safe Off feature of the Kinetix 300 Drive
About this lab
This lab will demonstrate the use of the Kinetix 300 Safe Off input used in the Safety Task of the 1769-
L43S Processor.
• Wire up the safe-off connection to the Kinetix 300 to the Logix Controller
• Understand the program to allow the Safe Off inputs to work properly
Understanding the Kinetix 300 Drive Safe Torque-off Feature
The safe torque-off circuit, when used with suitable safety components, provides protection according to
ISO 13849-1 Safety Category 3. The safe torque-off option is just one safety control system. All
components in the system must be chosen and applied correctly to achieve the desired level of operator
safeguarding. The safe torque-off circuit is designed to safely remove power from the gate firing circuits
of the drive’s output power devices (IGBTs). This prevents them from switching in the pattern necessary
to generate AC power to the motor. You can use the safe torque-off circuit in combination with other
safety devices to meet the stop and protection-against-restart requirements of ISO 13849-1.
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 of the drive’s 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 may 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 ISO 13849-1 safety category 3 both safety
channels must be used and monitored.
Wiring the Kinetix 300 to Use the Safe Off Function
1. Power off the demo unit by clicking the Main Power button OFF.
IMPORTANT:
This demo unit processor contains a flash card with logic files that are designed to
download on a power cycle (demo unit power OFF/ON). WHEN YOU NEED TO CYCLE THE DEMO
POWER, YOU WILL NEED TO DOWNLOAD YOUR LAB PROGRAM (.ACD file) TO OVERWRITE THE
FLASH CARD LOGIC FILE!
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