Rockwell Automation 20C-DG01 PowerFlex 700H AC Drive Safe Torque Off Option - Manual (Page 12)

12 Rockwell Automation Publication 20C-UM001B-EN-P - June 2011
Chapter 1 Overview
PFD and PFH Data PFD and PFH calculations are based on the equations from Part 6 of IEC 61508
and show worst-case values. This table provides data for a 20-year proof test
interval and demonstrates the worst-case effect of various configuration changes
on the data.
Table 1 - PFD and PFH for 20-year Proof Test Interval
Functional Proof Tests
The functional safety standards require that functional proof tests be performed
on the equipment used in the system. Proof tests are performed at user-defined
intervals and are dependent upon PFD and PFH values.
Contact Information if Safety Option Failure Occurs
If you experience a failure with any safety-certified device, contact your local
Rockwell Automation distributor. With this contact, you can:
• return the device to Rockwell Automation so the failure is appropriately
logged for the catalog number affected and a record is made of the failure.
• request a failure analysis (if necessary) to determine the probable cause of the
failure.
Attribute Test Result
PFD
av
1.52 x 10 -3
PFH 1.7 x 10 -8 1/h (calculated according to IEC 61508)
MTTF
D
High (2172 years)
DC
av
low (66%)
IMPORTANT Your specific application determines the time frame for the proof test
interval for the overall safety system.