If you do any larger commercial work, you've probably seen a DIN rail without knowing what it is called. It is simply a mounting standard that originated in Germany in the 80s and slowly worked its way over here. DIN rails can be used to mount terminal blocks, relays, starters, breakers, and just about anything […]

Diagram above by Carrier  It's really easy to put a liquid line drier in the proper location, but it's still more commonly installed in the WRONG location. Namely, people install it right at the condensing unit. (OK, it isn't that big of a deal, but I needed some dramatic emphasis.) Installing it at the indoor […]

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 […]