Carrier P421 4006 Thermistor Start Kit 321702 401 This low pressure switch is This low pressure switch is factory calibrated to actuate at 25 PSI and features a reset point of 55 PSI The Maxitrol RV48L 1 2 is a professional grade appliance gas regulator engineered for precision pressure control in high performance residential and commercial gas systems Universal Compatibility: This 208 230 Volt kit serves as a Carrier start assist capacitor alternative this Carrier compressor start thermistor kit typically includes the thermistor module and requisite wiring leads for parallel connection to the existing run capacitor