Are all ECM motors variable speed?

Asked By: Yekaterina Makoaga | Last Updated: 24th March, 2020
Category: home and garden indoor environmental quality
4.2/5 (947 Views . 27 Votes)
The term "Variable Speed" actually refers to the blower motor inside the furnace or air handler. It's an Electronically commutated motor, or (ECM). ECM's are DC motors that function using a built-in inverter and a magnet rotor, and as a result are able to achieve greater efficiency than most AC motors.

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Accordingly, what is the difference between an ECM motor and a variable speed motor?

Both variable speed and X13 motors are ECM or “Electronically Commutated Motors,” This means the DC power that drives them is electronically switched from positive to negative to spin the motor. The primary difference is the type of inputs to the motor control.

Subsequently, question is, do ECM motors have capacitors? ECMs are a type of DC motor. Permanent split capacitor (PSC) motors, often used in conjunction with electronic SCR motors, are somewhat inefficient when used in air control systems. This is because the fan motor noise requires the motor to run at less than a full load.

Also question is, are ECM motors reliable?

Not only are they simple and inexpensive, but they've proven to be an extremely reliable component. The average lifespan of a PSC motor is around 40,000 hours, though an ECM surpasses it at 90,000 hours.

What does ECM motor mean?

Electronically Commutated Motor

37 Related Question Answers Found

Is a variable speed AC worth it?

The downfall: Variable-speed costs more upfront
The cost to install a variable-speed AC unit is about $4,000–$8,000 more than other units. In fact, the overall cost of an AC installation varies depending on many factors, including: The size of your unit.

How do ECM motors work?

ECM stands for an “electronically commutated motor” which basically means a motor that uses electronic controls to vary its speed. There are three types of ECM motors: constant cfm, constant rpm, and constant torque. The microprocessor is the “brains” of the motor. It holds the logic that controls the motor.

Is a variable speed blower worth it?

meaning they are not very energy efficient. Variable-speed furnace motor — A variable speed blower motor runs at different speeds to precisely control the flow of heated air throughout your home. If you don't have a 90% efficiency or higher furnace in your home, then yes it may well be worth the cost to upgrade.

How does an ECM x13 motor compare to a PSC motor?

A PSC or permanent split capacitor is a type of motor that is designed to do two things. Because the motor operates at a constant speed, the use of energy is a constant and efficiency is lost. ECM Motors. ECM or electronically commutated motors save energy and improve the efficient movement of air through your unit.

What is the difference between a PSC motor and an ECM motor?


The big difference between the two models is that the PSC motor has one speed: full speed. Any time that the blower is on it blows at full force. The ECM model is a variable speed unit that will adjust the airflow to optimal levels based on the desired temperature of the home.

What is a constant torque ECM motor?

Constant torque motors are high-efficiency, brushless DC motors that are based on the same ECM technology described in ECM 2.3 variable-speed motors. In other words, if the ESP changes, then the motor program will maintain the amount of torque for which it was programmed (this is not the same as constant airflow).

What is x13 motor?

The X13 is constructed as one piece, with the two components of any ECM, the motor control and motor, housed inside one motor shell. It is a cross between a full-blown ECM motor and a standard PSC motor. However, the torque value programmed into each tap is determined by the HVAC Manufacturer.

Does my furnace have an ECM motor?

Electronically commutated motors (ECM) represent an advance in blower motor efficiency that saves substantial energy and improves aspects of overall system performance. Variable speeds – Unlike an on/off PSC motor, a furnace ECM motor can operate at a range of outputs between zero and 100 percent.

Are ECM motors quieter?

ECM motors are very high efficiency (65% to 80%) electric motors. ECM motors are also quieter than traditional inefficient motors, have longer design life and require less maintenance.

How much does an ECM motor cost?


HVAC Blower Parts Cost
Belt $5-$100
Pulley $50-$250
Housing $100-$300
Capacitor $150-$450
ECM Motor Module $230-$830

What are the principal advantages of ECM motors?

What are the principal advantages of ECM motors? High efficiency, Low maintenance, Speed control, Constant CFM etc.

Are ECM motors more efficient?

At low speed the ECM is over 30% more efficient than a standard induction motor. The ECM motor has a minimum efficiency of 70% throughout its entire operating range. Conventional induction motors become less efficient at the reduced speeds that are typically selected for fan powered applications.

What is ECM furnace?

An ECM furnace is equipped with an ECM (electronically commutated motor) to circulate hot air into the ducts that run through the walls of the building.

Why does a motor need a run capacitor?

Run capacitors
Some single-phase AC electric motors require a "run capacitor" to energize the second-phase winding (auxiliary coil) to create a rotating magnetic field while the motor is running. If a wrong capacitance value is installed, it will cause an uneven magnetic field around the rotor.

Do DC motors need capacitors?


If you really mean a capacitor in parallel with the power supply a DC motor is connected to, then that's just a capacitor holding up a supply. The capacitor keeps the voltage more steady, and keeps the high frequency noise current circulating close to the motor.

What's the difference between a start capacitor and a run capacitor?

The start capacitor creates a current to voltage lag in the separate start windings of the motor. The current builds up slowly, and the armature has an opportunity to begin rotating with the field of current. A run capacitor uses the charge in the dielectric to boost the current which provides power to the motor.

How do you size a capacitor for an AC motor?

Multiply 0.5 times the square of the voltage. Call this result "x.". Continuing the example, you have 0.5 times 11.5 volts times 11.5 volts, or 66.1 square volts for "x". Divide the start-up energy requirement, in joules, of the motor by "x" to arrive at the capacitor size needed in farads.