Westinghouse used to own the HVAC business, sold in 1982 as part of Mcquay. And Westinghouse developed the DP contactor/starter mainly for HVAC industry in 1970’s. and all the main competitor start to copy that. Since Eaton Cutler Hammer own the Westinghouse LV. Eaton has suppling the HVAC control panels for decades to main HVAC manufacturers like Trane, York, Carrier, and Mcquay.