DISCLAIMER: HVAC School is NOT an official OSHA safety training resource! Although we provide safety tips in good faith, our website is not a substitute for safety training from an authorized OSHA training source. Although we primarily work with our hands, our eyes are one of our most valuable assets in the industry. After all, […]

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 […]

Swaging copper is one of the most common practices in our trade when it comes to brazing pipes. Yes, it sometimes makes more sense to slap on a coupling or street ell fitting, but most of the time, cutting your braze joints in half is much easier and faster during an install or repair.  So, […]