We are making a study of whether the testing of interposing relays is a requirement outside the nuclear Industry for example?

We are evaluating a company who has developed an automated testing unit for the Clifford & Snell's D series relays for example.

The unit is capable of testing the relays to the original manufactures specification within 1 minute.

We have been advised to perform all of the tests by hand takes approx 15 minutes.

Your comments are welcome?

 

My question what benefit is there to testing interposing relays? They are no more or less likely to fail than the outputs controlling them. I would be inclined to just use process feedback to determine when one has failed, or just get rid of them if at all possible as something else that can fail.

 

another thought. it may well be cheaper to just replace these kind of relays as opposed to trying to test them.

--
Bob
http://ilbob.blogspot.com/

 

Interposing relays are used all over the world in all industries but I have never felt the need to test them on a regular basis, since like Bob said they are as likely to fail as any other component in your loop. The best you can do, and what we normally do, is to make use of the best quality relays that we can find with a proven reliability record. Personally I only work with AC/DC or Omron relay in applications like these but everyone will have his or her own preference.

Failures are just part of the game, you cannot prevent it, that is something you must accept. All you can do is to install the best and most reliable components in your system and make sure you have hot spares on hand and available for when any critical component in your application fails. I would advise against these tests you want to do on the IP relays since once you start down this road you will find that there is no end to it since there will always be more tests and things you would want to do to prevent failures but failures will still happen regardless and all you would achieve is stressing yourself out. Also in all my years I cannot remember about a time when I have had a IP relay failure. I remember failures of the solenoids that was driven by these IP relays or output card failure but not IP relay failures.