Compressor diagnostic system

• US 6,758,050 B2
• Filed: 11/21/2001
• Issued: 07/06/2004
• Est. Priority Date: 03/27/2001
• Status: Expired due to Term

• Current Assignee: Emerson Climate Technologies Incorporated (Emerson Electric Company)
• Original Assignee: Copeland Corporation LLC (Emerson Electric Company)
• Inventors: Jayanth, Nagaraj, Pham, Hung
• Primary Examiner(s): Tanner, Harry B.
• Application Number:
  US09/990,566
• Publication Number:
  US 20020170299A1
• Time in Patent Office: 958 Days
• Field of Search: 621/23, 621/26, 621/27, 621/29, 621/30, 622/30, 361/22, 361/23, 361/30, 361/31
• US Class Current: 62/126
• CPC Class Codes: B25J 9/1687 Assembly, peg and hole, palletising, straight line, weaving pattern movement
• CPC Class Codes: F04C 18/0215 where only one member is moving
• CPC Class Codes: F04C 2270/07 Electric current
• CPC Class Codes: F04C 2270/784 Light
• CPC Class Codes: F04C 2270/80 Diagnostics
• CPC Class Codes: F04C 2270/86 Detection
• CPC Class Codes: F04C 2270/90 Remote control, e.g. wireless, via LAN, by radio, or by a wired connection from a central computer
• CPC Class Codes: F04C 23/008 Hermetic pumps
• CPC Class Codes: F04C 28/06 specially adapted for stopping, starting, idling or no-load operation
• CPC Class Codes: F04C 28/28 Safety arrangements; Monitoring
• CPC Class Codes: F04C 29/0085 Prime movers
• CPC Class Codes: F25B 2700/151 of the compressor motor
• CPC Class Codes: F25B 2700/1931 Discharge pressures
• CPC Class Codes: F25B 2700/2106 of fresh outdoor air
• CPC Class Codes: F25B 2700/2116 of a condenser
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence
• CPC Class Codes: F25B 49/025 Motor control arrangements

Abstract

A refrigeration/air conditioning system includes a compressor having a motor protector which stops the compressor'"'"'s motor when it senses an out of specification condition. A diagnostic system of the refrigeration/air conditioning system monitors the status of the motor protector. The diagnostic system includes logic circuitry that diagnoses the type of problem the compressor or the system is having based upon the running times and status of the motor in conjunction with the times and status of the tripped motor protector. The diagnostic system also includes either a discharge pressure sensor or a condenser temperature sensor, an ambient air sensor and a voltage sensor. The sensors provide information to the diagnostic system which enables it to determine where a system fault has occurred.

Claims

1. A diagnostic system for a compressor assembly including a compressor and a motor protector, said system comprising:

a demand signal sensor;

a current sensor; and

logic circuitry associated with said current sensor, said demand signal sensor, and the motor protector, said logic circuitry operable to determine the trip frequency of the motor protector and identify a specific fault cause.

2. The diagnostic system according to claim 1, wherein said demand signal sensor monitors a supply voltage.

3. The diagnostic system according to claim 1, wherein said demand signal sensor is in communication with a system controller supplying a signal indicating demand.

4. The diagnostic system according to claim 1, wherein said logic circuitry is operable to output a coded sequence of electrical pulses to identify said specific fault cause.

5. A diagnostic system for a compressor assembly including a compressor and a motor protector, said system comprising:

a demand signal sensor;

a current sensor; and

logic circuitry associated with said current sensor, said demand signal sensor, and the motor protector, said logic circuitry operable to determine the average ON time of the compressor and identify a specific fault cause.

6. The diagnostic system according to claim 5, wherein said demand signal sensor monitors a supply voltage.

7. The diagnostic system according to claim 5, wherein said demand signal sensor is in communication with a system controller supplying a signal indicating demand.

8. The diagnostic system according to claim 5, wherein said logic circuitry is operable to output a coded sequence of electrical pulses to identify said specific fault cause.

9. A diagnostic system for a compressor assembly including a compressor and a motor protector, said system comprising:

a demand signal sensor;

a current sensor; and

logic circuitry associated with said current sensor, said demand signal sensor, and the motor protector, said logic circuitry operable to receive an output of said current sensor and an output of said demand sensor, derive a motor protector trip frequency from said received current and demand signal, and identify a specific fault cause.

10. The diagnostic system according to claim 9, further comprising an indicator associated with said logic circuitry, said indicator receiving a signal from said logic circuitry to indicate a fault based on said current and demand signal.

11. The diagnostic system according to claim 10, wherein said indicator is a plurality of lights indicating the presence or absence of a fault condition.

12. The diagnostic system according to claim 10, wherein said indicator is operable to communicate said specific fault cause.

13. The system according to claim 12, wherein said indicator is operable to visually communicate said specific fault cause.

14. The diagnostic system according to claim 9, wherein said demand signal sensor monitors a supply voltage.

15. The diagnostic system according to claim 9, wherein said demand signal sensor is in communication with a system controller supplying a signal indicating demand.

16. The diagnostic system according to claim 9, wherein said logic circuitry is operable to output a coded sequence of electrical pulses to identify said specific fault cause.

17. A diagnostic system for a compressor assembly, said system comprising:

a demand signal sensor;

a main winding current sensor;

an auxiliary winding current sensor; and

logic circuitry associated with said demand signal sensor, said main winding current sensor, and said auxiliary winding current sensor, said logic circuitry outputting a compressor operating condition signal based on input received from said demand signal sensor, main winding current sensor, and auxiliary winding current sensor.

18. The system according to claim 17, wherein said logic circuitry is operable in a normal run condition, said logic circuitry moving the protector to a tripped condition in the absence of a signal from both said main winding current sensor and said auxiliary winding current sensor.

19. The system according to claim 17, wherein said logic circuitry is operable in a protector trip condition, said logic circuitry outputting a normal run condition signal when receiving output from at least one of said main winding current sensor and said auxiliary winding current sensor and output from said demand sensor is acceptable.

20. The system according to claim 17, wherein said demand signal sensor monitors a supply voltage.

21. The system according to claim 17, wherein said demand signal sensor is in communication with a system controller supplying a signal indicating demand.

22. The system according to claim 17, wherein said logic circuitry determines the trip frequency of the motor protector.

23. The system according to claim 17, wherein the logic circuitry determines the average ON time of the compressor.

24. The system according to claim 17, wherein said logic circuitry derives a motor protector trip frequency from said input received from said demand signal sensor and at least one of said main and auxiliary winding current sensors.

25. The system according to claim 17, further comprising an indicator associated with said logic circuitry and operable to indicate a fault based on input received from at least one of said demand signal sensor, main winding current sensor, and auxiliary winding current sensor.

26. The diagnostic system according to claim 25, wherein said indicator is a plurality of lights indicating the presence or absence of a fault condition.

27. The diagnostic system according to claim 25, wherein said indicator is operable to communicate a specific fault cause.

28. The system according to claim 27, wherein said indicator is operable to visually communicate said specific fault cause.

29. A method for diagnosing a compressor assembly including a compressor and a motor protector, said steps comprising:

sensing a demand signal;

sensing a current;

analyzing said sensed demand signal and said current;

determining a trip frequency of the motor protector; and

identifying a compressor fault cause.

30. The system according to claim 29, wherein said step of identifying a compressor fault cause includes indicating a specific fault cause based on said sensed current and demand signal.

31. The system according to claim 29, wherein said step of identifying includes outputting a coded sequence of electrical pulses to identify a specific fault cause.

32. A method for diagnosing a compressor assembly including a compressor and a motor protector, said steps comprising:

sensing a demand signal;

sensing a current;

analyzing said sensed demand signal and said current;

determining an average ON time of the compressor; and

identifying a compressor fault cause.

33. The system according to claim 32, wherein said step of identifying a compressor fault cause includes indicating a specific fault cause based on said sensed current and demand signal.

34. The system according to claim 32, wherein said step of identifying includes outputting a coded sequence of electrical pulses to identify a specific fault cause.

35. A method for diagnosing a compressor assembly including a compressor and a motor protector, said steps comprising:

sensing a demand signal;

sensing a current;

analyzing said sensed demand signal and said current;

deriving a motor protector trip frequency from said sensed current and demand signal; and

identifying a compressor fault cause.

36. The system according to claim 35, wherein said step of identifying a compressor fault cause includes indicating a specific fault cause based on said sensed current and demand signal.

37. The system according to claim 35, wherein said step of identifying includes outputting a coded sequence of electrical pulses to identify a specific fault cause.