Auto reset is a valid consideration in a lot of applications, but should not be used indiscriminately. For instance, if it is a 2 hour drive on a dirt road to get to a remote pump station, automatic reset is a good idea since it will attemp to reset if there is a clog or stuck valve that may clear up. That said, I always recommend a short cycle timer to go with that so that you don't exceed the starts-per-hour rating of the motor.
Also, the OL relay must have a reset time that does not allow reset until the motor is sufficiently cool. Cheap-o ones unfortunately do not necessarilly provide that feature, so it comes back to "you get what you pay for". Thats why I try to use newer electronic overloads if the customer wants auto-reset now. The ones I use have starts-per-hour and minimum time between starts lockouts as well.
Given that an auto-reset OL, even a cheap-o, will still take 10 to 15 minutes minimum to reset, I seriously doubt that was the cause of your welded contacts. I would believe the interlock contact as a more likely scenario.
