a 3-pole contactor like this one is required to break all three lines of power simultaneously

the A2TXV01 expansion valve prevents liquid slugging of the compressor while maximizing heat transfer efficiency

It is designed to be paired with Emerson AM or ASC2 series coils

Why use 321 Stainless Steel instead of 304

Watts 0121406 Valve Els PW 29614 a 3-pole contactor like thisThe Watts 0121406 (Model 40L 3 150) is a high capacity automatic temperature and pressure relief valve designed specifically for large scale water heating systems and storage tanks. Featuring a 3 4 inch NPT male inlet and NPT female outlet, this Series 40L valve is engineered with a bronze body and a 3 inch extended thermostat reach to ensure accurate sensing in high volume applications. It provides critical protection with a pressure relief setting