Table of Contents
How do you diagnose a bad ECM motor?
Diagnosing ECM Motors
- Verify that the correct thermostat input voltage is present at the interface of the main control board on the furnace or air handler.
- When checking low-voltage connections, always use the C terminal on the board, never on the ground.
What causes ECM motors to fail?
Some older ECM motors will overheat and even fail when constantly running in over-amped conditions. Newer models are designed to drop airflow but time will tell on how well they will hold up. Other consequences of high static installations include noise at the registers from higher air velocities.
Do ECM motors have capacitors?
One of the characteristics of the ECM is that they do not require adding an external run or start capacitor. But a run capacitor may still be needed for the compressor. From the compressor the Start (S) and Run (R) leads are connected to the capacitor.
What controls an ECM motor?
In an ECM, this process is controlled electronically by a microprocessor and electronic controls, which provide the ability to increase or decrease the speed of the motor. The type of ECM currently used by most residential HVAC systems is a brushless dc three-phase motor with a permanent magnet rotor.
How is the speed of an ECM motor controlled?
In an ECM, this process is controlled electronically by a microprocessor and electronic controls, which provide the ability to increase or decrease the speed of the motor. The control then converts ac power to dc power to operate the internal electronics (thus the description of an ECM as a “dc motor”).
Are ECM motors variable speed?
Both variable speed and X13 motors are ECM or “electronically commutated motors,” which means that the DC power that drives them is electronically switched from positive to negative to spin the motor.
Why is the blower motor not working on my car?
If it doesn’t it could be the blower motor itself or the blower motor relay. If you switch the blower switch to high, it bypasses the blower motor resistor altogether. So even if the resistor fuse is blown, the motor itself should still work. If it doesn’t it could be the blower motor itself or the blower motor relay.
How is the speed of a blower motor controlled?
This means that the current running through the blower motor, and its’ speed is therefore controlled by the resistor value. The user chooses a fan speed by selecting a speed which then connects one of the resistors in the blower resistor pack. Blower resistors are made of several resistors with different resistances.
Where is the resistor on a blower motor?
The blower motor resistor is under the hood slightly below the blower motor mounted in the heater plenum. Dave look on the heater assimbly it should be behind the glove box it has three poles check it for a break in the wires. The blower motor resistor is under the hood slightly below the blower motor mounted in the heater plenum.
What causes a blower fan to turn faster?
The lower the resistance of the selected resistor in the pack, the higher the current that flows through the blower fan causing the fan to turn faster. The statements expressed above are only for informational purposes and should be independently verified.