What component is used in a sequencer to open and close its sets of contacts?

The bimetal element is the component used in a sequencer to open and close its sets of contacts. This element operates based on the principle of thermal expansion. When electrical current passes through it, the bimetal strip heats up and bends due to the different expansion rates of the metals used in its construction. As it bends, the bimetal element can move to make or break a connection, thereby opening or closing the contacts in the sequencer.

This action is crucial in HVAC systems for managing multiple stages of heating or cooling. The bimetal element provides a reliable and efficient means of controlling the sequence of operations, ensuring that multiple components can work harmoniously, such as starting one stage of heating before another.

Understanding the function of the bimetal element is essential for troubleshooting and maintaining HVAC systems, as it plays a key role in the proper sequencing of equipment operation.