On an energized, intact circuit, you will read voltage across an OPEN switch when testing with a voltmeter. However, you probably won't read significant voltage across a CLOSED switch. Both sides of a closed switch are electrically identical (or at least very close). Therefore, there should be no movement of electrons between the leads of […]

Every HVAC/R tech needs an electronic leak detector nowadays, and with HFC refrigerants getting more and more commonplace, every HVAC/R tech needs a VERY sensitive electronic leak detector. We often see three types, but let's toss out the corona discharge leak detector right off the top. It just picks up too many other types of […]

I had an old-timer tell me that you can never connect two transformers together because they will “fight one another.” If you are anything like me (and heaven help you if you are), a cartoon in your head starts playing whenever someone says something like that. In this case, I imagine two transformers with boxing […]