Thank you for the response on my sub panel questions. I finally found a slim line breaker which will work in my main panel. I can now consolidate two breakers to give me room for a 100 ap breaker. This breaker will feed the sub panel in my workshop. I plan on placing a 100 amp sub panel in the shop. I was consider using number 2 THHN wire to supply the sub panel. I believe the wire is rated at 130 amps. Since I live in Texas and the temp does rise to over 100 F and I will be placing the wires in a 2 inch conduit, I believe this wire will handle the load even after being derated. However, is number 2 wire too big? Can I use number 3 THHN wire to supply the sub panel? Also what is the difference between a CTL and Non-CTL breaker. Thanks in advance.

Use #2 THHN. #3 THHn is rated 100 amps only at ambient temp of 86 Deg F. The coorected capacity if the Amb is 96-104 F will drop the capacity down to 88 amps, 105-113 Deg F the amps drops to 82 amps.

#2 THHN starting at 130 amps, in 113 Deg F amb. Reduces to 106 amps.

The size conduit is irrelevant to ampacity or temp rating of any conductor.

Panelboards now, and for some time, but not always, are limited to 42 circuits, or poles, and are rated to take only CTL breakers, which will match the panelboard, and not allow changes or additions to the panel to exceed 42 circuits.

Non-CTL breakers are for older panels that are still in existence, were non CTL rated. These cannot be installed in a CTL rated panelboard, which all are now, or will void the UL listing of the panel, and then not comply with code.