9
Safe
Safe
Safe
Safe Torque
Torque
Torque
Torque Off (STO)
Off (STO)
Off (STO)
Off (STO)
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9
Safe Torque Off (STO)
9.1
General Introduction
The following documentation is meant to provide the basic information concerning our drive
controller and an understanding about the advanced, safety oriented machine construction.
References to standards or other regulations are made in a general overview manner. The specific
standards or regulations for your installation will vary depending upon the equipment employed and
the specifics of your application.
For more information we suggest referring to specific technical literature, for example:
BIA-Report 6/97, BIA-Report 5/2003 und BGIA-Report 2/2008
(Information of the German Professional Trade Association).
These reports can be downloaded from: http://www.hvbg.de/d/bia/pub/rep/index.html
●
Important Technical Terms and Explanations
Term
Explanation
Safety Category 3
Performance Level e
according to EN ISO 13849
Definition according to the regulation:
Circuit with built-in protective functions for individual fault conditions.
Some, but not all faults will be recognized.
The frequent occurrence of fault conditions can lead to a loss of the safety functions.
The remainder of the risk must be understood and accepted.
The determination for the application of the appropriate safety category
requirements, (risk analysis), lies with the installer and operator of the equipment.
You can reference the method described in EN13849-1:1996, Appendix B, as an
example.
‚Safe Stop’
or alternatively:
‚Safe Torque Off’
or abbreviated as:
STO
With the activation of “Safe Torque Off“, the energy supply to the drive is definitively
interrupted, according to the requirements of EN1037, section 4.1. The drive unit is
not allowed to rotate and will therefore not be able to generate any dangerous
rotational movements, (See EN 1037, section 5.3.1.3).
The stopping position must not be monitored.
Should there be the potential of an outside energy source affecting the drive and
STO
function, for example the dropping of a hanging load, then additional action needs to
be taken to guarantee that no additional movement takes place, (i.e. installation of a
mechanical brake).
The following measures are appropriate for incorporation with ”Safe Torque Off”:
-
Protection between power connection and the drive system
(Line Fault Protection)
-
Protection between the power unit and the motor (Motor Protection)
-
Protected lock of the control of the solid state power component
( Start-up Lockout)
Start-Up Lockout
Protected lock of the control of the solid state power component.
With help of this function one can establish the activation of the “Safe Torque Off”.
●
Stop Category according to EN 60204-1 (Chapter. 9.2.2)
Stop
Category
Requirement
System
Reaction
Note
0
Shutdown by immediate shut-off
of power supply to the machines’
driving components
Uncontrolled
Shutdown
Uncontrolled shutdown is the stopping of the
machines’ movement by eliminating the power supply
to the power components of the machine. Available
brakes and/or other mechanical braking systems
should be employed.
1
Shutdown, by a means which
maintains the power supply
connection to the machine drive
component, to bring movement
to a standstill. The power
connection will be broken only
after standstill has been
achieved.
Controlled
Shutdown
Controlled shutdown is the stopping of the machines’
movement by for example, the setback of the
electronic command signals to zero as soon as the
stop signal is recognized by the controller, while the
power supply to the machine drive components
remains intact until a standstill condition is achieved.
2
Shutdown, by a means which
maintains the power supply
connection to the machine drive
component.
Controlled
Shutdown
This category will not be covered in the functions
description of the manual.
This manual was downloaded on www.sdsdrives.com
+44 (0)117 938 1800 - [email protected]
