Arkansas HVACR NewsMagazine March 2022

HVACR NewsMagazine March 2022

Tech News

a path; it's like a drawbridge that allows cars to cross a river. There are many types of switches in low-voltage wiring, but a basic switch symbol will consist of two circles and a line. A normally closed switch shows that line connecting both circles. On the other hand, a normally open switch will have a line extending from one circle without making contact with the other.

You'll also see contacts in schematics, especially on relay connections. These may also be normally open or normally closed. As with switches, when contacts are

Every type of switch will contain two circles and a line to show whether they're normally open or normally closed. For example, a pressure switch looks like a basic switch symbol but with a bell shape extending from the bottom. A thermal switch has angled squiggly lines underneath, and a float switch has a circle extending from the bottom.

normally open, there is no path for electricity to flow through.