System Configuration Security; Safe Torque Off (Sto); Sto Activation; Automatic/Manual Restart Behavior - Danfoss iC7 Series Operating Manual

Operating Guide | iC7-Automation Functional Safety Functional Safety for Frequency Converters with STO, Not Upgradable (+BEF1)
2) Failure in demand or due to internal fault (always a "fault", not configurable). Indicated after discrepancy timer (500 ms) elapsed.

System Configuration Security

3.1.2
iC7 drives are equipped with mandatory and configurable security features that prevent unauthorized access to the drive, ensure secure
connectivity to the drive, and protect the drive against unauthorized software modifications.
For more details on the security features included in the application software, refer to application software documentation.
Configurable security features can be adjusted according to application requirements. The parameters related to safety are password-
protected.

Safe Torque Off (STO)

3.1.3
Select and apply the components in the safety control system appropriately to achieve the required level of operational
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safety. Before integrating and using STO in an installation, carry out a thorough risk analysis on the installation to determine
whether the STO functionality and safety levels are appropriate and sufficient.
The Safe Torque Off (STO) function is a component in a safety control system. STO prevents the unit from generating the power required
to rotate the motor.
The iC7 drives are available with:
Safe Torque Off (STO), as defined by EN IEC 61800-5-2:2017
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Stop category 0, as defined in EN IEC 60204-1:2018
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The STO function is available for iC7-Automation drives with functional safety plus code +BEF1. Specific hardware revisions are listed in
the appendix of the functional safety certificate.

STO Activation

3.1.4
The STO function is activated by removing the voltages at the STO inputs of the frequency converter. By connecting the frequency
converter to external safety devices providing a safe delay, an installation for a Safe Stop 1 can be obtained. External safety devices must
fulfill the required Cat./PL or SIL when connected to STO inputs.
With default settings, the frequency converter issues a fault, trips the unit and coasts the motor to a stop, when the STO function is
activated. Manual restart is required.
Use the STO function to stop the frequency converter in a situation where a safety function is required. In normal operating mode when
STO is not required, use the standard stop function instead.

Automatic/Manual Restart Behavior

3.1.5
The STO default state prevents unintended restarts (Restart Prevention Behavior).
The prevention of unintended restart after STO deactivation does not fulfill a SIL 2 or SIL 3 requirement.
If unintended restart is critical to the installation, this has to be controlled by the use of STO, both after STO activation and at
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normal startup scenarios, for example after normal power cycle.
The default restart behavior is set to Manual. Before switching to Automatic, ensure that requirements of EN ISO 12100:2011
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paragraph 6.3.3.2.5 are fulfilled.
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