Carrier HH21UB001 Vapor-Filled Temperature Switch

The Carrier HH21UB001 Vapor Filled Temperature Switch is an essential element in HVAC systems, this type of switch is used as a protection, which can turn off the system in case of overheating or freezing due to the changes of temperature inside the system. It is a sealed bulb that contains a volatile fluid which is connected to a switch mechanism through a capillary tube. This is because with increase in temperature around the bulb, the fluid boils and puts pressure into the sealed system. This pressure operates a diaphragm or bellows in the switch to opened or close the circuit at the required temperature level.