Hydraulic and Electrohydraulic Actuators
HAS Series Analog Drives Manual
53
Parker Hannifin Corporation
Cylinder Division
Des Plaines, Illinois USA
www.parker.com
/cylinder
Catalog HY08-4005-M3
WARNING:
This product can expose you to chemicals including
Lead and Lead Compounds
which are known to the State of
California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov
PROP 65 WARNING
Safe Torque Off
((S
Saaffeettyy ooff m
maacchhiinneerryy –– S
Saaffeettyy--rreellaatteedd ppaarrttss ooff ccoonnttrrooll ssyysstteem
mss))
STO aligns internally to the following aspects of this standard:
•
A
Arrcchhiitteeccttuurree aaccccoorrddiinngg ttoo C
Caatteeggoorryy 33::
Solid lines represent the STO control paths.
Dashed lines represent reasonably practicable fault detection.
Key:
I1, I2 = user terminal
L1, L2 = logic
O1, O2 = methods of enabling or disabling output power devices
imxy =
interconnecting means
mx
= monitoring
c
= cross monitoring
I1
L1
O1
I2
L2
O2
i
m1a
i
m2a
i
m1b
i
m2b
m
1
m
2
c
P
Paarrkkeerr H
Haannnniiffiinn C
Coorrppoorraattiioonn
Cylinder Division
Des Plaines, Illinois
50
w
ww
ww
w..ppaarrkkeerr..ccoom
m/
cylinder
•
C
Caatteeggoorryy 33 ggeenneerraall rreeqquuiirreem
meennttss aarree::
A single failure, and any consequential failures, will not lead to loss of the STO safety
function.
Failure of more than one component can lead to the loss of the STO safety function.
Most but not all single component failures will be detected. Diagnostic Coverage (DC) is
required to be at least 60% (i.e. the minimum required for ‘low’ diagnostic coverage).
Detected component failures will result in the STO function being applied without
intervention from the user.
The risk associated with the loss of STO safety function caused by multiple failures must
be understood and accepted by the user.
The user must undertake a risk analysis and specify suitable components that, when
connected together, meet the required risk assessment requirements.
Mean Time To Failure (dangerous) (MTTFd) of each STO channel must be ≥ 30 years.
Common Cause Failure (CCF) score must be ≥ 65 according to Annex F of the standard.
•
P
Peerrffoorrm
maannccee LLeevveell ee::
Average Probability of dangerous Failure per Hour (PFH) must be ≤ 10-7
Alignment to European Standards
ENISO13849-1:2008