First, circuit breakers should never be used as a switch unless they are rated for switching. If the breaker is switch duty rated it will be marked "SWR", "SDR" or "SW". This also stated in the Teco manual on page 14. (
www.tecowestinghouse.com/Products/Drives/fm50.html)
Second, someone at Factory Automation better read the user manual. According to the Teco FM50 manual single phase power HAS to be connected to L1 (R) & L2 (S), NOT L1 & L3.
The breaker is getting warm and tripping when connected the L1 & L3 because L3 is using a part of the internal power circuit reserved for 3 phase power. The breaker is doing it's job and protecting a miswire power connection. Changing the breaker will NOT fix the problem. Almost all single phase VFD's I've worked with ALL use L1 & L2 and Teco is no different.
Either you have a incoming power problem or a defective VFD. Seeing you changed the VFD once already and still have the exact same problem, then it points to the 213-215VAC power, which is low for a 220-240VAC circuit.