Siemens SINAMICS MV, Function Manual

Page: 10 / 26

with a very low probability, the machine builder (OEM) must carefully check as to whether
additional measures are required. Incorrect handling when the motor suddenly moves can result
in death, serious injury or substantial material damage.
• Adopt suitable protective measures to ensure that personnel is not endangered by the motor
jerking into motion from standstill.
• Carefully ensure that everyone operating the "Two-channel firing pulse inhibit" function are
adequately trained before they use the function. Training must include studying the function
and its integration into the production process. Documenting the training.
Danger due to the motor restarting
Drive systems, in which the energy supply to the motor is also possible via the load, e.g. marine
drives, conveyors, fans, etc., cannot be protected against restart using the "Two-channel firing
pulse inhibit" function. Sudden and unexpected restarting of the motor can result in death,
serious injury or substantial material damage.
• Take appropriate countermeasures, such as mechanical braking.
Danger by not waiting for the principle-related delay time to elapse
Selecting the "Two-channel firing pulse inhibit" function causes the firing pulses to be inhibited.
Due to the inherent operating principle, the firing pulses are inhibited after a short delay time.
The recommended delay time setting at the 3SK11 safety relay is 0.5 seconds.
Death and severe injury can occur if the delay time is not strictly observed.
• After externally activating the "Two-channel firing pulse inhibit" function, always wait until
the set delay time has elapsed.
• For the upstream safety controls, take into account this delay time when releasing protective
doors or other protective equipment.
Danger due to high voltage
The drive is not disconnected from the line supply when activating the "Two-channel firing pulse
inhibit" function. Dangerous voltages of over 1000 V are present on the motor and drive
converter. High voltages can cause death or serious injury if the safety rules are not observed or
if the equipment is handled incorrectly.
• Isolate the electrical equipment from the line supply at the main switch when it breaks down
or stops, or when it needs to be serviced, repaired or cleaned.
• Do not carry out any work on electrical connections without first applying all of the necessary
protective measures. Observe the 5 safety rules before undertaking work on the equipment.
Safety instructions
Two-channel firing pulse inhibit
8
Function Manual, 07/2021, A5E51227986A