H2013B-3 - 

Heater Pack Replacement The heater pack Series is determined by the 6th character of the Catalog Number. Series A or prior heater packs (identified by either “A” or “-” as the 6th character) have built-in load lugs. Series B or later heater packs do not (load lugs are on overload lay). Replacement of Series A or earlier heater packs with Series B or later heater packs, requires the one time addition of Lug Adapter Kit C3606KAL1-3B to the Series A1 overload relay.