KEB COMBIVERT G6 - Classification of STO According IEC 61508; Classification of STO According en ISO 13849

GB - 11
Safety Function STO
Jerks in error
case
In case of double malfunction it can lead to unwanted jerk, the
rotation angle is depending on the number of poles of the se-
lected drive and the gear ratio.
Calculation of the jerk:
Rotation angle of the jerk WR [°] =
180°
–––––––––––––––––––––––––––––––––
Pole-pairnumberp•gearreductionratiog
The probability of the jerk is < 1.84 *10
-15
1/h.
This behaviour can occur by a short circuit of the IGBTs. The error should be regarded as
critical, if the drive remains in STO status.
2.2 ClassicationofSTOaccordingIEC61508
PFH 8.1 *10^-11 1/h
PFD 7.1 * 10^-6 on demand
Proof-Test-Interval 20 years
ForSILclassicationinconnectionwiththeapplicationsconsiderthefailureratesoftheex-
ternalswitchdevicesfornalevaluation.
2.3 ClassicationofSTOaccordingENISO13849
Control category 3
MTTF
D
>2500 years
DC medium
Fortheclassicationwithinaperformancelevelinconnectionwiththeapplicationsconsider
thefailureratesoftheexternalswitchdevicesfornalevaluation.