In June 2020, Copperweld submitted a proposal to Standards Technical Panel STP-0013 with the intention of adding Copper-Clad Aluminum (CCA) to UL 13 — the standard for power-limited circuit cables. This would define CCA as a viable conductor option for Class 2, 150V-rated HVAC/Thermostat cable applications.

To achieve acceptance from the STP-0013, Copperweld conducted extensive electrical and mechanical testing, comparing the performance of 16 AWG CCA to 18 AWG copper conductors.  With consensus from STP-0013 members, it was concluded that the results of this testing clearly demonstrated that Copperweld 16 AWG CCA 10% conductors perform equivalently or better than an 18 AWG solid copper conductor.

As a result of this work, Copperweld is pleased to announce the revision of UL 13, 4^th Edition Standard with the inclusion of 16 AWG CCA for Class 2 HVAC/thermostat applications on March 18, 2022.  Later this year, Copperweld will be introducing a portfolio of UL 13-listed CCA thermostat cables.