NORD Drivesystems BU0530 - Manual (Page 46)

Functional safety with NORD SK 500E frequency inverters
46 BU 0530 GB-3712
6.4 ISO 13849-1:2006
(German version EN ISO 13849-1:2008)
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 Performance Level e. Safety category 4 can not be achieved.
Shut-down method “Safe pulse block”
PL e
DC cannot be established (PFH=0)
MTTF
d
"high" (>100 years)
T
M
20 years
Category 4
PL
Performance Level
DC Diagnostic coverage level
MTTF
d
The mean time until a hazardous failure
T
M
Period of use
The digital inputs which are used for the implementation of safety-relevant stop functions are primarily intended
as auxiliary inputs and can fulfil the requirements of Safety Category 1 and Performance Level c.
Input DIN 1 to DIN 4
PL c
DC No DC
PFH 588.39 FIT
MTTF
d
"high" (>100 years)
T
M
20 years
Category 1
NOTE
The values given only refer to the stated inputs or shut-down methods
The components which are additionally required for the implementation of a safety
function, such as a protective switching device, an emergency stop button etc. must also
be taken into account for the evaluation of the safety function. The resulting safety-relevant
data can be significantly influenced by these components.