NORD Drivesystems BU0530 - Manual (Page 45)

6 Safety categories
BU 0530 GB-3712 45
6 Safety categories
6.1 IEC 60204-1:2005
(German version EN 60204-1:2006)
The requirements of a Category 0 and Category 1 stop function can be fulfilled by the "safe pulse block".
The controlled braking for Category 1 is not fail-safe via the standard functions of the frequency inverter. The
switch-over to the stop function of Category 0 is fail-safe.
6.2 IEC 61800-5-2:2007
(German version EN 61800-5-2:2007)
The requirements for the functions "Safe shut-down torque (STO) and "Safe stop 1" (SS1) can be fulfilled with
the shut-down method "safe pulse block.
With the function SS1, there is no safe monitoring of motor speed reduction or motor speed reduction by the
frequency inverter. If a risk analysis has shown that monitoring is necessary, this must be carried out via an
external safe control unit. The solutions for the function SS1 described in the examples correspond to
characteristics as per IEC 61800-5-2:2007, Section 4.2.2.3, Paragraph c) "Triggering of motor speed reduction
and triggering of the STO function after an application-specific time delay". The motor speed reduction is
carried out via the standard functionality of the frequency inverter and is not fail-safe. The switch-over to the
STO function is fail-safe.
6.3 IEC 61508
Part 1: 2010
Parts -3, -4, -5: 1998 + Corrigendum 1999
Parts -2, -6, -7: 2000
(German version EN 61508, Part 1: 2010, Parts 2 to 7:2001)
For the safety-relevant stop functions STO and SS1 (designation as per IEC 61800-5-2:2007), frequency
inverters with the safe shut-down methods "safe pulse block" and "switch-off of the 24 V supply" fulfil the
requirements for SIL 3.
Shut-down method “Safe pulse block”
SIL 3
PFH 0
DC cannot be established (PFH=0)
SFF 100 %
T
M
20 years
SIL
Safety Integrity Level
PFH Probability of hazardous failures per hour
DC Diagnostic coverage level
SFF Proportion of safe failures
T
M
Period of use
The digital inputs do not have SIL capability