Can the AL1200P6KU lug kit be used on the I-Line version of Powerpact M and P circuit breakers?
No, the AL1200P6KU lug is NOT for I-line breakers. It is certified only for unit-mount breakers. The reasons includes wire bending space in I-Line panels, as well as electrical and mechanical interference with the I-Line mounting bracket, and lack of UL approval. For wire sizes/numbers that are not supported by the P frame, you can use the R frame which will take up to (4) 600 kcmil wires.