ECM motors | Hvac Pro Forums
ECM motors including the Variable Speed indoor blower motor models , relationships make us the preferred brand throughout the industry. . It is normal for the motor to rock back and forth on start up. Do not replace the. torque/speed relationship programmed by the HVAC OEM, the motor control is able . The variable speed ECM may rock back and forth when it first turns on. Trane/ AS has these ECM diagnostic modules that you can get to help . when its stuck rocking back and forth its usually a module failure, but.
The plug must be connected all the way and locked into place to prevent arcing. Also, to ensure proper operation and safety, the motor must have a properly grounded connection from the 5 pin connector to ground.
Now we have verified that we have line voltage to the motor but is still in not running. This involves checking the 16 pin harness to the module. Now you can start to check to see if the control or CFM programming board is sending the proper signals. Once you know what mode of operation you are in, you can now see if the board or control is sending out the proper communications to the motor module. This will give you the proper orientation to check the pins as needed.
Blower fan does not spin it actuates backand forth like a washing machine?
If you do not have 24 volts there, check the harness, check the connection at the board. Remove the harness from the board and see if you have 24 volts at those same pins on the board. If you do, the problem is in the harness. Keep in mind that pins 4, 5, 7, and 11 are not mentioned above. That is because these are not necessarily 24 volt outputs to the module.
ECM Motor Troubleshooting – Part 1 | York Central Tech Talk
As you can see from the diagram above, these can be 24 VAC or nothing or anywhere in between. None the less, these are the basic checks for the control board and inputs to the ECM motor module.
Always disconnect the power to the HVAC system before disconnecting or reconnecting any connectors to these motors. First check the high voltage to terminals L and N. On vac systems, make sure the polarity or the power connected to the motor is correct. If this voltage is missing, fix the problem in the system and try to run the motor.
Proper grounding should always be checked and repaired if needed. Also, if you read my post on X motors in 3-phase systems, both power legs to the X motor must be the same. Which tap s have been programmed and what are their purposes heating airflow, cooling airflow, continuous fan airflow. In other word, which is High, med high, med low, low-speed in relation to the positions on the motor.
Keep in mind, even though the motor has 5 possible inputs, with some applications, all of the taps may not be programmed. If no low voltage communication typically 24vac is measured at the motor on tapscheck the HVAC system wiring, controls and demand call. Always check low voltage between terminals and C at the motor, never ground.
Once the problem is corrected, confirm that the low voltage communication is applied to a programmed tap. If proper low voltage communication is present at a programmed tap, with proper high voltage to the motor and it still does not operate, the motor is failed.