Safe Stop Operation (Optional) - Danfoss VLT AQUA Drive Series Design Manual

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VLT AQUA Drive Design Guide

2.15.2 Safe Stop Operation (optional)

The FC 202 can perform the Safety Function "Uncontrolled Stopping by removal of power" (as defined by draft IEC 61800-5-2) or Stop Category 0 (as
defined in EN 60204-1).
It is designed and approved suitable for the requirements of Safety Category 3 in EN 954-1. This functionality is called Safe Stop.
Prior to integration and use of FC 202 Safe Stop in an installation, a thorough risk analysis on the installation must be carried out in order to determine
whether the FC 202 Safe Stop functionality and safety category are appropriate and sufficient.
The Safe Stop function is activated by removing the voltage at Terminal 37 of the Safe Inverter. By connecting the Safe Inverter to external safety devices
providing a safe relay, an installation for a safe Stop Category 1 can be obtained. The Safe Stop function of FC 202 can be used for asynchronous and
synchronous motors.
Safe Stop activation (i.e. removal of 24 V DC voltage supply to terminal 37) does not provide electrical safety.
NB!
The Safe Stop function of FC 202 can be used for asynchronous and synchronous motors. It may happen that two faults occur in the
frequency converter's power semiconductor. When using synchronous motors this may cause a residual rotation. The rotation can be
calculated to Angle=360/(Number of Poles). The application using synchronous motors must take this into consideration and ensure
that this is not a safety critical issue. This situation is not relevant for asynchronous motors.
NB!
In order to use the Safe Stop functionality in conformance with the requirements of EN-954-1 Category 3, a number of conditions must
be fulfilled by the installation of Safe Stop. Please see section
NB!
The frequency converter does not provide a safety-related protection against unintended or malicious voltage supply to terminal 37
and subsequent reset. Provide this protection via the interrupt device, at the application level, or organisational level.
For more information - see section
Safe Stop Installation
Safe Stop Installation .
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