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 […]

It should be stated and restated that codes and code enforcement vary from location to location within the US. The IMC (International Mechanical Code) is one of the most widely utilized and referenced. The 2015 version of the IMC section 307 is what I will be referring to in this article. Condensate Disposal  The code […]

This article was written by Regan Murphy. Thanks, Regan! Disclaimer: Any percentages used are the opinion of the author and not based on any actual facts. You are probably already used to getting the model and serial numbers of the equipment. You may have even made a habit of getting the part number, but there […]