Do I need to include a ferrite core in an FMEA

Thread Starter

alanj100

Joined Apr 26, 2019
19
I am doing an FMEA on a product with a ferrite core with 13 wiring running through it. 1. do I need to include it in an fmea and if I do what are the failure modes and where will I find mode probability figures?
thanks
 

KeithWalker

Joined Jul 10, 2017
2,400
What are their specific requirements of the organization are you doing the analysis for? I would think they are the only ones who could answer your question.
Regards,
Keith
 
Last edited:

ci139

Joined Jul 11, 2016
1,855
i just looked up the term from wiki . . . but if it's the integral part . . . of the system -- you might address it with appropriate weight -e.g.- if it's main function is to reduce RFI either direction then the ferrite may develope unipolar magnetiztion . . . either by time or by an exceptional DC event (say at power ON or at power OFF) . . . therby reducing it's functionality . . . i can't hint the probabilities for such
 

kubeek

Joined Sep 20, 2005
5,774
Is it an EMI supression ferrite on a cable? Or a transformer? or something else? That really makes things different.
If it is the emi kind, then I see two possible failure modes:
1) the core breaks and looses effective permeability, therefore the emi supression works less or not at all. Depending on the wires you could have worse emi radiation from the product, or you could have more susceptibility and data errors.
2) two or more wires get shorted through the ferrite. Depends on the physical construction, but should be relatively improbable, or pretty much impossible with correct physical construction.
 

prairiemystic

Joined Jun 5, 2018
275
Yes the component must be included in the FMEA. I focus on open-circuits for ferrite inductors as that is usually the worst case and how they fail. The failure rate data you can get from the manufacturer as each has unique construction. Otherwise go to the same source for failure rate numbers you are using for the other components.
 

vu2nan

Joined Sep 11, 2014
249
The ferrite core would need to be included. The failure modes for the ferrite core could be overheating or breakage.

- Nandu.
 
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