Method of controlling a pump and motor

Patent metadata

Field	Value
Publication number	US-9590537-B2
Application number	US-201414216918-A
Country	US
Kind code	B2
Filing date	Mar 17, 2014
Priority date	Mar 15, 2013
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

Embodiments of the invention provide a variable frequency drive system and a method of detecting a ground in a system having a pump driven by a motor. The drive system and method can provide one or more of the following: a sleep mode, pipe break detection, a line fill mode, an automatic start mode, dry run protection, an electromagnetic interference filter compatible with a ground fault circuit interrupter, two-wire and three-wire and three-phase motor compatibility, a simple start-up process, automatic password protection, a pump out mode, digital input/output terminals, and removable input and output power terminal blocks.

First claim

The invention claimed is:

1. A method of detecting a ground in a water distribution system having a pump coupled to a motor, the motor being driven by a drive located in an enclosure, the method comprising:
determining whether a voltage exists at least one of on the enclosure, inside the enclosure, and in proximity to the enclosure, the enclosure at least partially enclosing the drive of the water distribution system;
if the determination is that the voltage exists, (i) starting a fault timer and (ii) incrementing the fault timer;
determining whether the fault timer has exceeded a predetermined time period;
if the fault timer has exceeded a predetermined time period, determining that the water distribution system is not grounded; and
upon determining the water distribution system is not grounded, stopping the motor.

2. The method of claim 1 wherein determining whether the voltage exists includes measuring the voltage across a discrete component inside the enclosure.

3. The method of claim 2 wherein the discrete component is a chassis of the drive.

4. The method of claim 1 wherein testing for a voltage includes measuring the voltage using an integrated voltmeter.

5. The method of claim 1 wherein the predetermined time period is about 72 hours.

6. The method of claim 1 wherein stopping the motor includes coasting the motor to a stop.

7. The method of claim 1 and further comprising indicating to a user that the system is not properly grounded when the fault timer has exceeded the predetermined time period.

8. The method of claim 1 and further comprising returning to a normal operation if no voltage is present and the enclosure is properly grounded.

9. The method of claim 1 and further comprising determining whether a motor frequency of the motor is greater than zero before testing for a voltage.

10. The method of claim 1 wherein the motor is a variable speed motor and the drive is a variable frequency drive and further comprising causing the variable frequency drive to coast the variable speed motor to a stop.

11. The method of claim 1 and further comprising testing for a voltage at least once per 24 hour period.

12. The method of claim 1 and further comprising automatically testing for a voltage.

13. A water distribution system comprising:
a pump;
a motor coupled to the pump;
an enclosure;
a controller including a drive connected to the motor, the controller housed in the enclosure and configured to:
(i) determine whether a voltage exists at least one of on the enclosure, inside the enclosure, and in proximity to the enclosure, the enclosure at least partially enclosing the drive of the water distribution system;
(ii) if the determination is that the voltage exists, (a) start a fault timer; and (ii) increment the fault timer;
(iii) determine whether the fault timer has exceeded a predetermined time period;
(iv) if the fault timer has exceeded a predetermined time period, determine that the water distribution system is not grounded; and
(v) upon determining the water distribution system is not grounded, stop the motor.

14. The system of claim 13 wherein the controller measures the voltage across a discrete component inside the enclosure.

15. The system of claim 14 wherein the discrete component is a chassis of the drive.

16. The system of claim 13 wherein the controller measures the voltage using an integrated voltmeter.

17. The system of claim 13 wherein the predetermined time period is about 72 hours.

18. The system of claim 13 wherein the controller coasts the motor to a stop.

19. The system of claim 13 wherein the controller indicates to a user that the system is not grounded when the fault timer has exceeded the predetermined time period.

20. The system of claim 13 wherein the controller returns to a normal operation if no voltage is present and the enclosure is properly grounded.

21. The system of claim 13 , wherein the controller determines whether a motor frequency of the motor is greater than zero before testing for a voltage.

22. The system of claim 13 wherein the motor is a variable speed motor and the drive is a variable frequency drive and wherein the controller causes the variable frequency drive to coast the variable speed motor to a stop.

23. The system of claim 13 wherein the controller tests for a voltage at least once per 24 hour period.

24. The method of claim 13 wherein the controller automatically tests for a voltage.

Assignees

• Pentair Flow Tech Llc

Inventors

• Pasche Micheal Robert
• Baase Ii Gary Thomas
• Genaw William James

Classifications

• G01R31/50

  Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections (testing of sparking plugs H01T13/58) · CPC title

• F04B2203/0202

  Voltage · CPC title

• F04B49/10

  Other safety measures · CPC title

• F04B49/02

  Stopping, starting, unloading or idling control · CPC title

• H02P3/06 Primary

  for stopping or slowing an individual dynamo-electric motor or dynamo-electric converter · CPC title