DIAGNOSTIC SYSTEM

• US 20100293397A1
• Filed: 05/17/2010
• Published: 11/18/2010
• Est. Priority Date: 05/18/2009
• Status: Active Grant

• Current Assignee: Copeland Corporation LLC (Emerson Electric Company)
• Original Assignee: Emerson Climate Technologies Incorporated (Emerson Electric Company)
• Inventors: Pham, Hung M., Jayanth, Nagaraj
• Granted Patent: US 10,024,321 B2
• Time in Patent Office: Days
• US Class Current: 713/300
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04B 51/00 Testing machines, pumps, or pumping installations
• CPC Class Codes: F04C 18/0215 where only one member is moving
• CPC Class Codes: F04C 2240/81 Sensor, e.g. electronic sensor for control or monitoring
• CPC Class Codes: F04C 2270/07 Electric current
• CPC Class Codes: F04C 2270/80 Diagnostics
• CPC Class Codes: F04C 2270/86 Detection
• CPC Class Codes: F04C 23/008 Hermetic pumps
• CPC Class Codes: F04C 28/28 Safety arrangements; Monitoring

Abstract

A compressor is provided and may include a shell, a compression mechanism, a motor, and a diagnostic system that determines a system condition. The diagnostic system may include a processor and a memory and may predict a severity level of the system condition based on at least one of a sequence of historical-fault events and a combination of the types of the historical-fault events.

Claims

1. A compressor comprising a shell, a compression mechanism, a motor, and a diagnostic system for determining a system condition, said diagnostic system including a processor and a memory and operable to predict a severity level of said system condition based on at least one of a sequence of historical fault events and a combination of the types of said historical fault events.

2. The compressor of claim 1, further comprising a current sensor in communication with said processing circuitry.

3. The compressor of claim 2, further comprising at least one of a low-pressure cutout switch, a high-pressure cutout switch, and a motor protector.

4. The compressor of claim 3, wherein said processing circuitry determines a state of at least one of said low-pressure cutout switch, said high-pressure cutout switch, and said motor protector based on information received from said current sensor and compressor ON times and OFF times.

5. The compressor of claim 1, further comprising at least one of a low-pressure cutout switch, a high-pressure cutout switch, an ambient-temperature sensor, a discharge-temperature switch, and a pressure-relief valve.

6. The compressor of claim 5, wherein said processing circuitry determines severity of a low-side system condition based on at least one of an order sequence and a combination of:

compressor run time, opening of said low-pressure cutout switch, motor-protector trips, and discharge-temperature-switch trips.

7. The compressor of claim 6, wherein said discharge-temperature-switch trips are detected based on a predetermined rate of decrease of compressor current.

8. The compressor of claim 7, wherein said predetermined rate of decrease is approximately twenty percent (20%) to thirty percent (30%) within a period of approximately two (2) to five (5) seconds.

9. The compressor of claim 5, wherein said processing circuitry determines severity of a high-side system condition based on at least one of a sequence or combination of:

opening of said high-pressure cutout switch, motor-protector trips, and pressure-relief-valve trips.

10. The compressor of claim 9, wherein said pressure-relief-valve trips are detected based on a predetermined rate of decrease of compressor current.

11. The compressor of claim 10, wherein said predetermined rate of decrease is approximately twenty percent (20%) to thirty percent (30%) within a period of approximately two (2) to five (5) seconds.

12. The compressor of claim 1, wherein said processing circuitry determines the rate of progression over time of said types of historical fault events within said order sequence or combination.

13. The compressor of claim 1, wherein said severity level is based on said sequence or combination of historical fault events all recurring within a predetermined time period.

14. The compressor of claim 13, wherein said predetermined time period is one of a week, a month, a summer season, or a winter season.

15-24. -24. (canceled)

25. A refrigeration system comprising:

a compressor including a motor;

a motor protector associated with said motor and movable between a run state permitting power to said motor and a tripped state restricting power to said motor;

processing circuitry including an output to a compressor contactor and operable to restrict power to said compressor via said contactor when said compressor experiences a condition of a predetermined severity level; and

at least one of a low-pressure cutout switch movable between a closed state and an open state in response to system low-side pressure and a high-pressure cutout switch movable between a closed state and an open state in response to system high-side pressure, said low-pressure cutout switch and said high-pressure cutout switch wired in series between said processing circuitry and said compressor contactor.

26. The refrigeration system of claim 25, further comprising a current sensor in communication with said processing circuitry and sensing a current drawn by said motor.

27. The refrigeration system of claim 26, wherein said processing circuitry distinguishes between said motor protector being in said tripped state and either of said low-pressure cutout switch and said high-pressure cutout switch cycling between said closed state and said open state based on an OFF time of said compressor.

28. The refrigeration system of claim 25, wherein said processing circuitry declares said motor protector being in said tripped state if said compressor OFF time exceeds substantially seven (7) minutes.

29. The refrigeration system of claim 25, wherein said processing circuitry declares cycling of either of said low-pressure cutout switch or said high-pressure cutout switch if said compressor OFF time is less than substantially seven (7) minutes.

30. The refrigeration system of claim 25, wherein said processing circuitry differentiates between a low-side fault or low-pressure switch cycling and a high-side fault or high-pressure switch cycling based on a compressor ON time prior to said cycling of said motor protector.

31. The refrigeration system of claim 30, wherein said processing circuitry determines said low-side fault when said compressor ON time is greater than thirty (30) minutes.

32. The refrigeration system of claim 30, wherein said processing circuitry determines said high-side fault when said compressor ON time is between one (1) and fifteen (15) minutes.

33. The refrigeration system of claim 30, wherein said processing circuitry determines a combination of said high-side fault and said low-side fault when said compressor ON time is between fifteen (15) and thirty (30) minutes.

34. The refrigeration system of claim 25, further comprising a demand signal wired in parallel with said at least one of said high-pressure cutout switch and/or said low-pressure cutout switch.

35. The refrigeration system of claim 25, further comprising a demand signal wired in series with said at least one of said high-pressure cutout switch and/or said low-pressure cutout switch.