Danfoss Reliability Data (MTTF) Application guide
Functional Safety
Reliability Data (MTTF)
for PLUS+1 Microcontrollers and I/O
modules
www.danfoss.com
Functional Safety
Reliability data (MTTF) for MC and I/O modules
Revision history Table of revisions
Date Changed Rev
February 2020 Component and calculation summary chapter/topic MC050-010 added 0304
January 2020 Corrections made in Component and calculation summary 0303
December 2019 Component and calculation summary chapter/topic MC050-110 and MC050-118 replaced
MC050-110; Added row to Device total table with MC050-118 information
July 2016 First edition 0101
0201
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Functional Safety
Reliability data (MTTF) for MC and I/O modules
Contents
Overview
Reliability Data (MTTF)....................................................................................................................................................................4
Standards and references
Introduction........................................................................................................................................................................................5
Assumptions.......................................................................................................................................................................................5
Standards.............................................................................................................................................................................................5
Calculations........................................................................................................................................................................................ 5
Component and calculation summary
MC012-110 and IOX012-110........................................................................................................................................................ 6
MC024-110..........................................................................................................................................................................................6
MC024-120 and IOX024-120........................................................................................................................................................ 7
MC024-130..........................................................................................................................................................................................7
MC050-010..........................................................................................................................................................................................8
MC050-110 and MC050-118.........................................................................................................................................................9
MC050-120....................................................................................................................................................................................... 10
MC050-155....................................................................................................................................................................................... 11
OX012-110........................................................................................................................................................................................11
OX024-110........................................................................................................................................................................................12
Terms and definitions
PFH and FIT.......................................................................................................................................................................................13
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Functional Safety
Reliability data (MTTF) for MC and I/O modules
Overview
Reliability Data (MTTF)
Transfer of Mean Time to Failure (MTTF) data for the given product from Danfoss to the appropriate party.
This Mean Time to Failure (MTTF) data has been compiled by the Business Area engineering team
responsible. These are professionals at Danfoss, who have the authority and technical knowledge to
calculate the MTTF Data for this product based on the standards set in place by both the industry and/or
Danfoss.
The purpose of this document is to assist in the transfer of MTTF data for the given product from Danfoss
to the appropriate party in a way which will result in a clear understanding and documentation on how
we derived it.
This MTTF data is provided to assist in calculating the overall MTTF of a complete or partially complete
piece of machinery. Danfoss cannot be held responsible for the suitability of these calculated MTTF
values for use in the calculation of the overall machinery MTTF values.
The MTTF values are based on a specific machine use, operating environment, and/or duty cycle as stated
by the standards set in place by both the industry and/or Danfoss.
This communication along with any attached Danfoss drawings, sketches, or data is transmitted in
confidence. No information stated in this document or any attachments or supplements may be
reproduced or disclosed in whole or in part without written permission of Danfoss. Further, neither these
documents nor any attachments are a warranty of any sort by Danfoss or a guarantee of machine
suitability for its intended purpose. It remains the responsibility of the machine manufacturer to ensure
overall machine functionality and overall machine safety.
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Functional Safety
Reliability data (MTTF) for MC and I/O modules
Standards and references
Introduction
As of December 29, 2009, Machinery Directive 2006/42/EC is effective for all machinery placed on the
market in the European community. This directive mandates that machinery manufacturers are
responsible for performing and documenting a Hazard and Risk Assessment. Each identified risk must
then be addressed to ensure risk reduction to an acceptable risk level.
The processes to guide the execution of these activities are defined in various harmonized standards
such as:
•
ISO 12100:2010 Safety of Machinery
General principles for design
‒
Risk assessment and risk reduction
‒
•
ISO 13849 Safety of Machinery
Safety-related parts of control systems
‒
Danfoss adds value by participating in the machine manufacturers process and providing the appropriate
product information to enable the required probabilistic calculations.
Assumptions
The failure rate listed in this document is the result of a FMEDA analysis.
All failure rates were calculated using component data from MIL-HDBK-217F at 45°C, unless otherwise
noted. All failure mode distributions were taken from IEC 62061:2005 Annex D.
For inputs, a failure included in MTTFd and PFH is categorized as a mismatch between expected and
measured signal.
For logic and outputs, failure included in MTTFd and PFH is categorized as one that causes:
•
Loss of high-side switch turn-off capability
•
Uncommanded turn-on of high-side switch
•
A mismatch between commanded and actual current (for proportional outputs only)
Analysis should be performed, taking into account if not all components fail dangerously.
Standards
IEC 61508:2006
IEC 62061:2005 Annex D
MIL-HDBK-217F
Calculations
Probability does not consider CAN communication external issues.
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PLUS+1® microcontroller hardware category - Type B device
Failure modes and percentages
Reliability prediction of electronic equipment
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