I have spent the last few days checking run capacitors on various systems with several different meters, and this is what I found: #1 – Comparing Start wire amps against Run + Common under the clamp together is meaningless as a practical test. I used this test on 3 different systems with 3 different meters […]

This article includes significant contributions from Neil Comparetto and Brian Chadwick, both of whom are HVAC technicians in Virginia. Brian is also the owner of Chadwick Air, and Neil is a co-owner of Comparetto Comfort Solutions and a longtime contributor to HVAC School. Thanks, guys! DISCLAIMER: A lot of the information in this article is […]

We've been getting many questions on micron gauges that are ”going haywire” or reading in the micron range, even at atmospheric pressure. First, micron gauges measure absolute pressure, so you can’t ”zero” them out. They use tiny, very sensitive sensors that are calibrated to air, not refrigerant, so anytime refrigerant gets into the gauge, it's […]