One of the most common mistakes I hear techs make is confusing zero ohms with infinite ohms. The fuse above is showing near-zero ohms, which indicates a good electrical path with very little resistance. If there is a perfect path, it would have zero ohms (which isn't actually possible unless you happen to be […]

Not if you are hungry, anyways— A true story. I have a good friend who owns an HVAC company. Not much of a Ph.D., but he is known to be honest, doesn’t pull vacuums through manifolds, and claims to almost always use American-made capacitors. We’ll call him Captain Kirk. He called me recently, quite worked […]

This article is written by Sal Hamidi, founder of Productsbypros.com, an innovative manufacturers representative agency that promotes great HVAC/R products through training and media. You can reach Sal at Sal@productsbypros.com.   If we are going to discuss vacuum pump oil, it's important to understand what it is first. Most HVAC application vacuum pumps are rotary […]