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Rockwell Automation Publication 7000-UM203C-EN-P - September 2018
Chapter 2
Safety Concept
Reliability Data for 12-year Mission Time Test
Safe State
The Safe State encompasses all operation that occurs outside of the other
monitoring and stopping behavior of the drive as defined as part of the normal
operation without the Safe Torque Off Option.
If a Functional Safety System Fault is detected, the safety option goes to the
Safe State. This includes faults related to integrity of hardware or firmware.
Safety Reaction Time
The safety reaction time is the amount of time from a safety-related event as
input to the system until the system is in the Safe State.
The safety reaction time from an input signal condition that triggers a safe
torque off to safe state reached is 1000 ms (maximum).
Considerations for Safety
Ratings
The achievable safety rating of an application using the safety option installed
in PowerFlex 7000 drives is dependent upon many external factors.
For applications that rely on the immediate removal of power to the actuator,
resulting in an uncontrolled coast to stop, a safety rating up to and including
SIL CL3, PLe, and Cat. 3 can be achieved.
Attribute
Value
(1)
(1) STO data for all medium voltage drive frames.
PFH
2.26 E-8 1/hour
SIL CL
3
PL
e
Category
3
MTTF
d
803 years
DC
avg
90%
HFT
1
PTI (Proof Test Interval)
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IMPORTANT
An input signal condition that is present for less than the reaction time may
not result in the safety function being performed. A request of the safety
function for less than the reaction time may result in the detection of a fault.
Summary of Contents for PowerFlex 7000 Series
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