It’s an important question when having a motor replaced: Is a PSC or EC motor better?
When replacing blower motors in heating and cooling equipment, HVAC technicians must identify which motor is the best option. Understanding the differences between motors can help installers solve customer challenges. The right motor will increase efficiency, improve indoor comfort and operate safely within the OEM’s specifications.
Let’s cover the basics on what a PSC and EC motor is, the differences between the two and the option that comes out on top.
PSC vs EC Motors
A PSC (permanent split capacitor) is a type of motor used that turns on and off. It’s commonly used on fans, blowers, small pumps and gear motors. Chances are, your existing HVAC equipment has a PSC motor.
With a PSC motor, the electrical output is not controllable and has no intermediate speeds. It’s either running at full speed or not running at all. As you can imagine, it’s easy to waste energy this way. This is why the HVAC industry is switching to a new option: EC motors.
EC (electronically commutated motors) allow for variable speeds, saving energy and improving efficient air movement. Typically, ECMs will turn on gradually instead of suddenly, slowly increasing the speed of the fan. This lets the ECM reach the maximum speed that is needed as specified by the thermostat.
Why More HVAC Companies are Switching to ECMs
As stated before, many installed air conditioners and furnaces have a PSC model as their original blower motor. Therefore, EC motors are typically installed when the furnace or air conditioner needs a motor replacement. These motors are a top choice for Global Warming and Cooling for the following reasons:
- Variable speeds. Unlike a PSC motor that turns on and off, an EC motor can operate at a range of speeds. This can be adjusted from a controller or programmed to do so. And, ECMs feature soft stops instead of abrupt ones.
- Energy savings. EC motors are more costly to install than PSC motors. However, they deliver much higher efficiencies, offsetting the cost difference and saving money over the long run.
- Longer lifespan. ECMs have ball bearings that need lubrication less often. Plus, the gradual stops put less wear and tear on the parts. On average, EC motors last about 10 years compared to the 8 years you get with a PSC.
- Increased comfort. Because ECMs run at a lower output, temperatures are more consistent. This increases indoor air comfort. Additionally, ECM units have longer periods of circulation in the air ducts, improving indoor air quality.
As you can see, EC motors are the preferred choice for the HVAC industry. When replacing a blower motor, expect your Global Warming & Cooling tech to recommend a motor of this sort. You will enjoy increased comfort, less maintenance and greater efficiency for years to come.