There is a great deal of difference in the types of overcurrent circuit protectors available to eliminate electrical circuit overloads. To this end, the following article link is offered to assist one in understanding the differences in the requirements and test parameters of UL489 – the standard for Molded-Case Circuit Breakers and UL1077 – the standard for Supplementary Protectors for Use in Electrical Equipment (aka CBEs – Circuit Breakers for Equipment).
http://www.mechprod.com/circuit-breakers---ul-standards/
The article provides a solid background in UL’s qualification requirements for switching and push to reset circuit protectors. Both trip free and cycling trip free devices are reviewed for such performance characteristics as overload and short-circuit conditions, endurance, resistive and motor start applications, and level of agency oversight.