Heavy duty connections were originally developed to be used on reclaimed cable. The heavy duty connections use a larger size connection cavity in the mold and a larger size welding material than the equivalent standard duty connection.
The larger size welding material supplies extra BTU’s to melt the heavy oxide coating on the conductor and to overcome some severe field conditions. Heavy duty connections eliminate cutting the run conductor on certain types of connections, reduce cable cleaning requirements for old or reclaimed cable, and increase reliability under adverse field conditions.
Heavy duty connections are increasingly being specified for copper-coated steel conductor connections.