In residential air handler/fan coils, it is common to use a high-voltage interlock between the blower and the electric heat strips to ensure that the blower comes on whenever the heat is on. The problem is that it CANNOT work the other way around where the heat comes on with the blower. Heat strips are […]

I hear the following phrase a lot: It's the amperage that kills you, not the voltage. While there is truth to the statement, it is sort of like saying, “It's the size of the vehicle, not the speed that kills you when it hits you.” OK, so that's a pretty bad example, but hopefully, it […]

Often in commercial HVAC and refrigeration, you'll come across a sight glass/moisture indicator on the liquid line. (Oil sight glasses also exist, but those are different from what I'm talking about today.) Sight Glass The sight glass portion is simple; it's just there to show if the liquid line has a full line of liquid […]