BLOWER MOTOR FOR HVAC SYSTEMS

• US 20100060219A1
• Filed: 09/08/2008
• Published: 03/11/2010
• Est. Priority Date: 09/08/2008
• Status: Active Grant

• Current Assignee: Nidec Motor Corporation (Nidec Corporation)
• Original Assignee: Emerson Electric Company
• Inventors: Woodward, Arthur E., Schock, Christopher D.
• Granted Patent: US 8,294,393 B2
• Time in Patent Office: Days
• US Class Current: 318/400.210
• CPC Class Codes: F04D 25/06 the pump being electrically driven F04D25/08 takes precedence
• CPC Class Codes: F04D 27/001 Testing thereof; Determination or simulation of flow characteristics; Stall or surge detection, e.g. condition monitoring
• CPC Class Codes: H02H 1/0007 concerning the detecting means in general G01R or other subclasses of G01; reed switches H01H71/2445
• CPC Class Codes: H02H 7/097 against wrong direction of rotation

Abstract

A blower motor assembly having a variable speed motor that is suitable for direct, drop-in replacement in a residential HVAC (heating, ventilation, and air conditioning) system that employs a PSC motor. The blower motor assembly includes at least a neutral input and two hot AC line connections, one for connection to the heating power source and the other to the cooling power source. A sensing circuit senses which of the inputs is energized by sensing either voltage or current on the inputs. The sensing circuit delivers a corresponding signal to a motor controller to control the speed of the variable speed motor. The blower motor assembly may also be equipped with additional hot AC inputs, more than one neutral line, and several sensing circuits for sensing current or voltage in the hot inputs and/or the neutral lines for controlling various aspects of the variable speed motor.

Claims

1. A method for determining proper rotation direction of a reversible motor, the method comprising:

operating the motor to rotate the fan in a first direction;

monitoring an operating parameter of the motor while the fan is rotated in the first direction;

determining if the monitored operating parameter is within an acceptable range; and

determining that the first direction of rotation is not the proper rotation direction where the monitored operating parameter is not within the acceptable range.

2. The method as set forth in claim 1, further comprising:

operating the motor to rotate the fan in a second direction if the monitored operating parameter is not within the acceptable range;

monitoring a second operating parameter of the motor while the fan is rotated in the second direction;

determining if the second monitored operating parameter is within the acceptable range; and

determining that the second direction of rotation is not the proper rotation direction where the monitored operating parameter is not within the acceptable range.

3. The method as set forth in claim 2, further comprising changing a memory setting of a motor controller coupled with the motor to indicate that the second direction is the proper rotation direction when the second monitored operating parameter is within the acceptable range.

4. The method as set forth in claim 1, wherein the motor is a variable speed motor.

5. The method as set forth in claim 1, wherein the operating parameter is a torque load.

6. The method as set forth in claim 4, wherein the variable speed motor is a brushless permanent magnet motor.

7. The method as set forth in claim 2, wherein the first direction is counter-clockwise and the second direction is clockwise.

8. A method for determining proper rotation direction of a blower fan driven by a reversible motor in an HVAC system, the method comprising:

operating the motor to rotate the fan in a first direction;

monitoring an operating parameter of the motor while the fan is rotated in the first direction;

monitoring a rotation speed of the fan;

determining if the monitored operating parameter is appropriate for the monitored rotation speed; and

determining that the first direction of rotation is not the proper rotation direction where the monitored operating parameter is not appropriate for the monitored rotation speed.

9. The method as set forth in claim 8, further comprising:

operating the motor to rotate the fan in a second direction if the monitored operating parameter is not appropriate for the monitored rotation speed;

monitoring a second operating parameter of the motor while the fan is rotated in the second direction;

monitoring a rotation speed of the fan while the fan is rotated in the second direction;

determining if the second monitored operating parameter is appropriate for the monitored rotation speed for the second direction; and

determining that the second direction of rotation is not the proper rotation direction where the monitored operating parameter is not appropriate for the monitored rotation speed.

10. The method as set forth in claim 9, further comprising changing a memory setting of a motor controller coupled with the motor to indicate that the second direction is the proper rotation direction when the second monitored torque load is appropriate for the monitored rotation speed.

11. The method as set forth in claim 8, wherein the motor is a variable speed motor.

12. The method as set forth in claim 8, wherein the operating parameter is a torque load.

13. The method as set forth in claim 11, wherein the variable speed motor is a brushless permanent magnet motor.

14. The method as set forth in claim 9, wherein the first direction is counter-clockwise and the second direction is clockwise.

15. A blower motor assembly comprising:

a fan;

a reversible variable speed motor and motor controller for rotating the fan in first or second directions; and

a sensing circuit for sensing a torque load on the motor while the motor rotates the fan in the first direction;

the motor controller being operable for determining whether the monitored torque load is within an acceptable range and for determining that the first direction of rotation is not the proper rotation direction where the monitored torque load is not within the acceptable range.

16. The blower motor assembly as set forth in claim 15, the motor controller being further operable to rotate the fan in a second direction if the monitored torque is not within the acceptable range.

17. The blower motor assembly as set forth in claim 16, wherein the sensing circuit monitors a second torque load on the motor while the fan is rotated in the second direction, the motor controller determines if the second monitored torque load is within the acceptable range, and the motor controller determines that the second direction or rotation is not the proper rotation direction where the monitored torque load is not within the acceptable range.

18. The blower motor assembly as set forth in claim 17, the motor controller being further operable to change a memory setting of the motor controller to indicate that the second direction is the proper rotation direction when the second monitored torque load is within the acceptable range.

19. The blower motor assembly as set forth in claim 15, wherein the variable speed motor is a brushless permanent magnet motor.

20. The blower motor assembly as set forth in claim 16, wherein the first direction is counter-clockwise and the second direction is clockwise.