Tech Tips

Let's take a walk through the startup and commissioning procedure of a conventional or “single” refrigeration condensing unit. We’re going to start with a unit that is fully piped in and has been pressurized for leak and strength testing. For brevity, we are going to assume a basic familiarity with industry standards, company and customer […]

If you don't do a lot of commercial work, you may see a system like the one above and wonder what the heck it is. It is a 100% fresh air unit or a makeup air unit. You will see them more and more as codes start to reflect that balanced ventilation and conditioned outdoor […]

Our technician, Sam, sauntered into my office this afternoon like techs often do on a slow spring afternoon before the summer hits. It's been a long day for me, lots of training prep, a bunch of little fires, and errands to stomp out, and I still didn't get my article for the day written. I […]

The chart above is from a Carrier heat pump, and it lists some common accessories. I have heard this common pressure switch (last on the list) called a low-pressure switch (because it opens on fall in pressure) and a high-pressure switch (because it's in the liquid line), but RARELY do I hear it called its […]

A 40VA transformer is rated for 40 VA or volt-amps on the secondary. For a typical 24 volt secondary, this is simply using Watt's law to calculate amperage. (For more information on Watt's or Ohm's laws, please check out this article HERE.) 40 ÷ 24 = 1.666666 ∞ (round up to 1.67 already) So, you […]

Yes, I'm walking a fine line with that title or even writing about Labor Day or workers' movements at all. So, let's take a step back, strip away the politics and economic theory, and talk about this from a human standpoint. Peter McGuire was born in New York in the 1850s to a poor family […]

Oil pressure controls, oil failure controls, oil safety controls… They’re a pain in the neck when they trip, and diagnosing those problems can really tax even the best of techs. As semi-hermetic compressors get larger, they can no longer rely on simple splash or “sling” type lubrication strategies where oil is just flung around inside […]

This is Part 4 series by Senior Refrigeration Tech (and prolific writer) Jeremy Smith. Pay attention to this one, folks. I know rigging and safe lifting practices may be boring to some of you, but it could very well save your back or your life. Disclaimer This article is written by a technician representing his […]

This is Part 3 series by Senior Refrigeration Tech (and prolific writer) Jeremy Smith. Pay attention to this one, folks. I know rigging and safe lifting practices may be boring to some of you, but it could very well save your back or your life. Disclaimer This article is written by a technician representing his […]