Relays can be used for many different control applications, including controlling fans, blowers, other relays, or contactors, valves, dampers, pumps, and much more. A 90-340 is a very common, versatile relay that many techs have on their truck. So, we will use it as an example. A relay is just a remotely controlled switch that […]

This article was submitted by Genry Garcia of Comfort Dynamics, Inc. It is the final part of his series on zonal pressure diagnostics. Thanks, Genry! Updated 3/4/2022 Picking up where we left off in part 2 of the series, we discussed how a pressure reading from an attached zone indicates only the ratio of the […]

You have seen the C terminal on a dual run capacitor before. You have also seen the C terminal on a compressor. It stands to reason that they would both connect together, right? They don't connect, and they aren't even related, at least not in the way you think. In both cases, the C denotes […]