Why is it called single-phase 240 when there are two opposing phases (or legs)? I wondered why we called two 120v opposing legs “single-phase 240” for years. Then someone pointed out to me that a typical “single-phase” pole transformer only has one power leg entering and two coming out. That freaked me out. How can […]

If you are new to the trade, I'd like to welcome you. Like many skilled trades, the HVAC/R trade has many opportunities and can help you make a good living. If you are young and new to the trade, we need you. We are grateful to have you. However, if you aren't thoughtful, you might […]

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 […]