Contactor Alternatives and Upgrades
Our HVAC equipment can’t run without the contactor coil, but contactors can develop problems with age and during high-voltage electrical events. Contact pitting is unmistakable, and it’s unfortunately all too common in areas where bugs can get into the coil and fry on the contacts. Factor in problems with the utility, such as brownouts and […]
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Condenser Fan Blade Placement
In a previous article, I talked about wiring permanent split capacitor (PSC) condenser fan motors. While researching the topic, I realized that there isn’t as much information available on condenser motors as there is on their counterpart—the indoor blower motor. I had never really given it much thought, as I assumed that the condenser motor […]
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The Difference Between Variable-Speed and X13 Motors
First, let’s cover the basics. X13 is a brand name for the Regal Beloit/Genteq brand of constant torque motors; there are other manufacturers that make them, but the term “X13” has become pretty much synonymous with the fractional horsepower HVAC constant torque motor. Also, this article specifically discusses common residential/light commercial motors. There are other […]
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Diagnosing ECM & X13 Motors
First, let’s give proper credit. Most of the best practices and tools for diagnosing ECM and X13 motors come from Regal/Genteq and their site, thedealertoolbox.com, and their app, The Dealer Toolbelt (available on the App Store and Google Play). Your best bet is to follow the practices shown there and use their TECInspect diagnostic tool […]
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Capacitor Testing and Replacement Procedure
❶ Understand What a Run Capacitor Does The run capacitor provides continuous phase-shifted current to the motor start winding, allowing the motor to run: With the design efficiency In the right direction With the appropriate torque With near “unity” power factor (power factor near 1.0) If the run capacitor is failed, the motor often won’t […]
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Potential for Good and Evil (The Hard Start & Potential Relay)
I have spent most of my career being afraid of hard start kits; I heard too many horror stories of start caps exploding and sales technicians telling every customer they need one. It dawned on me recently that it may be time for me to take a more mature look at start capacitors, potential relays, […]
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What does “RES” mean on a contactor or relay?
Go to your truck, pick up a contactor, and look at it closely. You may find some interesting ratings you never noticed—things like terminal ambient temperature ratings and torque specs. One reading you may overlook is the RES AMPACITY of the contactor or relay. The RES rating is the RESISTIVE LOAD AMPACITY (amperage capacity) or rating. […]
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Understanding Relays With the 90-340
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 […]
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Some Belt Tensioning Thoughts
We had a really great conversation on the HVAC School Facebook Group about some belt tension best practices. It turns out that even a lot of really smart and experienced techs are not aware of all the factors related to belt tensioning. Myth #1 is that amperage is used to set belt tension. Now, don’t […]
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