Life of an Electromechinical relay
Life of an Electromechinical relay
(OP)
Does anyone know a good reference for determining the usable life of an electromechinical relay?
I know we have had to replace some capacitors, but other than ocasusinal failures they seem to be holding up well.
I know we have had to replace some capacitors, but other than ocasusinal failures they seem to be holding up well.






RE: Life of an Electromechinical relay
I am speaking of the IAC and CO units.
Probably see more problems with the older ACR and RC reclosing relays.
Alan
RE: Life of an Electromechinical relay
Is this a protective or control relay? 217F covers control relays. The IEEE Gold Book may also be useful.
http://www.sre.org/pubs/Mil-Hdbk-217F(2).pdf
RE: Life of an Electromechinical relay
RE: Life of an Electromechinical relay
David Castor
www.cvoes.com
RE: Life of an Electromechinical relay
Of course when one caught a fault and operated, all it did was drop a little orange flag.
old field guy
RE: Life of an Electromechinical relay
RE: Life of an Electromechinical relay
By the way, I often say that the biggest mistake of relay engineers was when we left design of relay protections to computer guys. The result is 500+ pages User Manual for overcurrent relay !
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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant
RE: Life of an Electromechinical relay
My coworkers said, 75 years or the span of two protection engineers.
I do believe that in this case the panels included ACR's, which seem morl likely to become jammed due to lack of grease, or hardining of the orignal grease (we'll blame it on poor maintenance).
RE: Life of an Electromechinical relay
RE: Life of an Electromechinical relay
Alan
RE: Life of an Electromechinical relay
First problem was the ACR case wasen't wired as expected. That corrected, the next time it was called on to reclose, it was burned up.
The replacment we purchased was better to work with.
However they haven't reported any problems yet.
I just don't want to go replacing relays because they are old. I want to see a real reason.
Thanks for your input. This is good information
RE: Life of an Electromechinical relay
Granted there have been many instances where I have needed different curves or functions and could have used a micro based relay, but most of the time they are perfect for the job.
The manufacturers are always pressing to get the latest and greatest set of bugs (firmware upgrades) in all of the existing relays in the field, but I do not do the upgrades unless absolutely necessary. I have upgraded the firmware in relays and had them not operate as advertised. Then I end up flashing it back to the old version. That means that every time I do the upgrade, I am also doing another full commission test....and who needs to be doing that!
The capability of a few cycle delay in the inst is what I miss most of the time.
Alan