The AA is an auxiliary contact, UO is a 24Vdc under voltage trip, which are the same for the Powerpact L-frame. The L9 is a disconnect harness (S29272) factory installed. For Powerpact L:
YH1 Wiring Harness for all installed non-communication accessories except neutral CT and ZSI
YH2 Wiring Harness for all installed non-communication accessories PLUS neutral CT
YH3 Wiring Harness for all installed non-communication accessories PLUS ZSI
YH4 Wiring Harness for all installed non-communication accessories PLUS neutral CT and ZSI
YH1 Wiring Harness for all installed non-communication accessories except neutral CT and ZSI
YH2 Wiring Harness for all installed non-communication accessories PLUS neutral CT
YH3 Wiring Harness for all installed non-communication accessories PLUS ZSI
YH4 Wiring Harness for all installed non-communication accessories PLUS neutral CT and ZSI