Warning Omron Relaysgreenspun.com : LUSENET : Elevator Problem Discussion : One Thread
To everyone: Omron has come out with a new 4PDT MY4N series. Here is the problem...the new design is of same polarity. If you get an Omron 4 pole relay, and it looks like a new design, check the box and see if it is marked "same polarity only". Omron failed to put this warning on the relay. Make sure the device you are plugging that relay into is not polarity sensitive. The relay model number is the same, however, it has a (S) marked on the box. Omron is selling these as direct replacements for their 4PDT. Be sure your purchasing people know what they are buying.
-- Bob (firstname.lastname@example.org), May 25, 2000
Relays with internal diode often have this polarity related problems. If internal diode becomes short for some reason then relay also becomes useless. Hence, I advice to use the diode for protection out side the relays as far as possible.
-- Shyam Sunder Tiwari (email@example.com), June 19, 2003.