For safety reasons, I would not want a circuit to try to come back on after a short was detected, or even an over load.
Back a few years ago a few in the wall/window room air conditioners that had electric heat was designed manufactured and sold through the Fedders and Sears brand name with a automatic resetting thermo overload for the high temperature safety for the heating element shroud area, these caused a few fires when the blower motors failed, the hi temperature bug would just keep cycling and eventually the ABS plastic shroud would melt till it came in contact with the heating element and burst into flames. I did a discovery on one and sent all the info to UL, and pointed out about the improper use of the auto resetting hi limit. and an nation wide recall was sent out.
Safety devices should always be a manual type reseting device never automatic.
It seems there could be a subtle difference in your example - between an overload/short circuit protection device and a thermal overload?
I agree 100% and I do not believe that any safety device should self-reset. Yet you see manufacturers get away with using self resetting thermal snap switches all the time.
In my design experience for the industrial environment we never allowed an over temperature circuit to self reset. Yet commercially they seem to get away with it.
I have ceramic top cooking unit in my kitchen that uses electronic (triac control) for the normal heating setpoint and thermal snap switches to protect against the elements over heating.
When I boil water on this unit with the electronic control knob set to 100%. The unit heats up and then eventually begins cycling on/off due to the thermal snap switches. (
makes for a long boil time)
When I called to point this out to the company they said it was normal operation. I then followed up with a letter to the company explaining how I felt this was a safety issue.
They finally agreed to send a technicain out to look at it. He observed the behavior and said that was normal :roll:
I am not too concerned as there are no combustibles around the metal shrouded elements but I could not understand how they could get away with such a design. I am anxious to replace the unit with gas:grin:
Glad to hear you got such as positive response to your issue.