All of the customers equipment is periodically tested by a testing company. The cost to have someone travel here to test just one breaker would make up a significant portion of the cost to just replace it.
The cable will be protected by a breaker that is properly sized for both the cable and the load served so I don't see any problems with doing this. True, it will be a different style breaker with different sensing/trip characterstics and will not be a true test of the suspect breaker but if it holds then it will allow me to keep the customer's operation going while the original breaker is shipped, tested, and return shipped.
