What is an FR, KR, or LR circuit breaker and are they still available?
Legacy F, K, L frame circuit breakers
There never were FR, KR, or LR type circuit breakers. Catalog numbers such as FRP36030 or KRL36250, etc. are in fact FAP36030 and KAL36250, etc.
The font used on some labels is easily mis-read. "R" is not valid in the second position for any of the F, K, L, M, N, P frame legacy circuit breakers. The letter that looks like an R is an A.
NOTE: FAR, KAR, LAR are valid prefixes. They were for a drawout I-Line panel. They are obsolete and no replacements or parts for them are available.