Motors, Capacitors & Starting Components

Take a look at the specs from this Copeland scroll compressor pulled from the Copeland Mobile App (which is an incredible app, by the way). These specs are for a single-phase compressor, so the amperages listed are based on an amperage reading from the wire connected to the common terminal. LRA is the locked rotor […]

An important rating on motors is the AMBIENT  temperature rating at which the motor can operate. This rating refers to the temperature of the air around the motor, not the temperature of the motor itself or even the temperature of the outdoor air, since the motor is often in a condenser air stream that is at […]

Service calls about condensing fan motor failure are quite common. Even though fan motor replacement is a standard procedure for residential split systems, it requires careful attention to safety and detail. This article will give you a step-by-step guide showing how to replace a condensing fan motor. Along the way, we will also explain a few […]

Along the path to becoming a great HVAC technician lies the dreaded wiring diagram. It's meant to be a helpful map of the equipment's electrical system, but with its crisscrossing lines and cryptic symbols, it often feels more like a barrier than a guide. If this sounds familiar, you're not alone. But what if you […]

One of the most common parts to fail on a single-phase HVAC system is the run capacitor, so much so that we sometimes refer to junior techs as “capacitor changers.” While capacitors may be easy to diagnose and replace, here are some facts many techs may not know: Capacitors Don't “Boost” the Voltage  A capacitor […]

Ever since Nikola Tesla invented the modern induction motor, we have been struggling with varying the speed of motors efficiently and reliably. The trouble in the HVAC industry is that there are several different types of technologies in play, including ECM, VFD, and inverters, and they can easily get confused. ECM (Electronically Commutated Motor) In […]

I used to call PTCR devices a "Soft Start". I was wrong.

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 […]

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 […]