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Correcting a typo in my previous e-mail. The changes in the new paragraph are highlighted.
Hamid Wasti wrote:
Lets say you have a system where the "A Buss" and "B Buss" feed an essential buss and the diode on the A Buss side has failed with high resistance. If you do a system check at every startup where you sequentially shut down both busses and make sure that the essential buss can run from the remaining one, you are likely to find that the essential buss works. The failed diode will be able to operate the load for a little bit while it over-heats. During normal operation, the diode on the A Buss will take all the load. But if you have a failure of the A Buss and all the current starts going through this high resistance diode, it is quickly going to fail and as Murphy's Law states, there is 100% likelihood that this will be one of the 30% of times where it fails open.
Lets say you have a system where the "A Buss" and "B Buss" feed an essential buss and the diode on the _*B Buss*_ side has failed with high resistance. If you do a system check at every startup where you sequentially shut down both busses and make sure that the essential buss can run from the remaining one, you are likely to find that the essential buss works. The failed diode will be able to operate the load for a little bit while it over-heats. During normal operation, the _*good*_ diode on the A Buss will take all the load. But if you have a failure of the A Buss and all the current starts going through this high resistance diode _*from the B Buss*_, it is quickly going to fail and as Murphy's Law states, there is 100% likelihood that this will be one of the 30% of times where it fails open.
Regards,
Hamid
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