Emerson Exchange 365

Every (as in 300) LS DO CHARMs FAILED

Good Afternoon,

Has anyone else had all of their LS DO safety system CHARMs fail at once?  All LS AI, LS DI, LS IS AI, etc were not affected.

All of our safety system DOs LS DO CHARMS failed.  

We did have a power excursion.  I do not question the fact that the power voltage drop could have caused the issue.  I want to know why only the Safety System LS DO CHARMs failed.

No BPCS DO CHARMS Failed....In fact nothing else failed other than the LS DO CHARMs.  But it was a total failure.  It was scattered throughout 12 CSLS.  The LS DOs were on different baseplates.  There were LS DI and LS AI etc surrounding the failed LS DO CHARMs.  None of the surronding (non LS DO CHARMs) were affected.

Please help Emerson explain how this could occur.  My safety system is on the same isolated ground and UPS, Power supply as my BPCS.  I just want a root cause (FET?).  How would FET fail on only the safety system DOs and not circuit protection on all the other CHARMs in my system? 

I really appreciate any help on this. 

Petrisky

• 4 Apr 2024 7:22 PM
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5 Replies

• Andre Dicaire

  

  • 4 Apr 2024 10:37 PM

  Have you sent any of the CHARMS to Emerson for a root cause analysis? I don't think speculation in this forum can serve a useful purpose. Obviously, the different CHARM types have different components and would react differently to an electrical surge.
  
  But the first thing to do is get confirmation of the actual failure mode of the CHARMs and from there determine what could possibly result in that damage and confirm the presence of those conditions.

  Andre Dicaire

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• Tadeu Batista

  

  • 5 Apr 2024 4:37 PM

  Petrisky ,
  
  Help me understanding what happened here, after a power outage/failure, all CHARMs went back up to normal, all LS Input CHARMs went back to normal, only the LS Output CHARMs did not came back?
  
  And you said 300 LS Output CHARM, so I'm assuming they are all across several CSLS' right?
  
  We need you to open a call with global support (GSC) so we can further investigate what's going on here.
  
  Rgs,

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• Petrisky

  

  • 10 Apr 2024 2:48 PM

  In reply to Tadeu Batista:

  we have an open call with GSC. The we have 12CSLS's and there are LS DOs on each CSLS. All the LS DOs failed.
  
  None of the other CHARM types failed.
  
  There was a power voltage drop on the incoming power for 2 seconds. There is not any data collection as to how low the voltage got, or high it surged on the rebound. The entire excursion lasted 2 seconds or less.
  
  As I said, I don't question why it failed. I am sure it had to do with power surge. My question is: Why are the LS DOs more fragile? Do the LS DOs need to be more protected in the future? Why didn't the DO HSS CHARMs in the BPCS fail?
  
  I just want help figuring out how to prevent the failure of all my LS DO CHARMs if another power excursion happens in the future.

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• Tadeu Batista

  

  • 10 Apr 2024 4:02 PM

  In reply to Petrisky:

  Petrisky
  
  All this questions should be addressed on the GSC Call you opened, this is not a normal behavior on the LS DO, there's something else going on and must be properly investigated.
  
  Rgs,

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• Tadeu Batista

  

  • 12 Apr 2024 6:21 PM

  In reply to Tadeu Batista:

  Petrisky , I could not find any GSC call related to the issue described here, please reach me out in private with the GSC call number.

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