Fundamentally, three-phase, alternating current motors are about as simple as a motor gets. The power company produces three phases by spinning magnets. Then, on the other end, we produce electromagnets that spin the motor according to the same 60 cycles per second frequency (60hz). All three phases are 120 degrees out of phase from one […]

Suction pressure, head pressure, subcooling, superheat, delta T. Taking all five of these calculations into account on every service call is critical. Even if you must do further diagnostic tests to pinpoint the problem, these five factors are the groundwork before more effective diagnostics can be done. I would also add static pressure as an […]

Jesse Grandbois is a tech who reads the tech tips, and he wrote a few tips that he wanted to share on some gas furnace control basics. This tip is about how to use a fancy digital stat on a millivolt system. For those of you who don't know, a millivolt system uses a thermocouple/thermopile […]