Techniques for detecting ground failures in bathing installations

• US 6,629,021 B2
• Filed: 06/22/2001
• Issued: 09/30/2003
• Est. Priority Date: 09/03/1998
• Status: Expired due to Term

• Current Assignee: Balboa Water Group LLC (Helios Technologies, Inc.)
• Original Assignee: Balboa Instruments Incorporated (Helios Technologies, Inc.)
• Inventors: Pinkul, Allan, Cline, David J., Otto, Cindy
• Primary Examiner(s): Paladini, Albert W.
• Assistant Examiner(s): CABRERA, ZOILA E
• Application Number:
  US09/888,331
• Publication Number:
  US 20020038169A1
• Time in Patent Office: 830 Days
• Field of Search: 700/300, 700/11, 700/14, 700/15, 700/17, 700/21-22, 340/649, 340/650, 361/42, 361/49, 361/115, 449/3, 454/12
• US Class Current: 700/300
• CPC Class Codes: A61H 2201/0176 By stopping operation
• CPC Class Codes: A61H 33/005 Electrical circuits therefor
• CPC Class Codes: F24H 15/124 Preventing or detecting electric faults, e.g. electric leakage
• CPC Class Codes: F24H 15/20 characterised by control inputs
• CPC Class Codes: F24H 15/215 before heating
• CPC Class Codes: F24H 15/219 after heating
• CPC Class Codes: F24H 15/281 Input from user
• CPC Class Codes: F24H 15/335 Control of pumps, e.g. on-off control control of compressors of heat pumps F24H15/38
• CPC Class Codes: F24H 15/37 of electric heaters
• CPC Class Codes: F24H 15/395 Information to users, e.g. alarms
• CPC Class Codes: F24H 15/407 using electrical switching, e.g. TRIAC
• CPC Class Codes: F24H 15/414 using electronic processing, e.g. computer-based
• CPC Class Codes: F24H 9/2028 Continuous-flow heaters
• CPC Class Codes: H02H 3/335 the main function being self testing of the device
• CPC Class Codes: H02H 5/105 responsive to deterioration or interruption of earth connection for preventing switching-on H02H11/001

Abstract

A control system for bathers with ground continuity and ground fault detection includes an electronic controller which controls operation of electrically powered devices such as an electric heater assembly connected in a water flow path for heating water. A solid state water temperature sensor apparatus provides electrical temperature signals to the controller indicative of water temperature at separated first and second locations on or within the heater housing. A solid state water presence sensor apparatus determines the presence of water within the heater housing, providing electrical water presence signals to the controller indicative of the presence or absence of a body of water within the heater housing. The system includes ground continuity detection, ground current detection and ground fault detection circuits. The ground continuity detector detects continuity of the electrical ground and provides an electrical detector signal to the controller indicative of a ground continuity status. The ground current detector detects a current flow in the electrical ground line and provides a detector signal to the controller indicative of the current flow detection. The ground fault detection circuitry detects a current imbalance in high power conductors, and disconnects high power outputs from the respective spa devices when a current imbalance is detected, without disconnecting power from the controller.

Claims

1. A method for verifying the integrity of an electrical ground connection to earth ground for an electrically powered circuit in a bathing installation, comprising:

controlling operation of the electrically powered circuit in the bathing installation by a microcomputer-based electronic controller system;

detecting with the microcomputer-based electronic controller system a condition that the electrical ground is not connected to earth ground; and

providing an electrical detection signal from said microcomputer-based electronic controller system indicative of said condition when the electrical ground is not connected to earth ground.

2. The method of claim 1, wherein said electrically powered circuit includes a heater circuit including an electric heater element, the method further comprising:

powering the heater circuit by a line voltage connection;

disconnecting the line voltage connection from said heater circuit when the electrical ground is not connected to earth ground.

3. The method of claim 2, further comprising:

powering the heater circuit by a line voltage connection;

disconnecting the line voltage connection from said heater circuit when the electrical ground is not connected to earth ground.

4. The method of claim 2, further comprising:

inhibiting operation of the heater circuit when the electrical ground is not connected to earth ground.

5. The method of claim 1, further comprising:

generating an electrical control signal from said microcomputer-based electronic controller system to deactivate said electrically powered circuit in the event said electrical ground is disconnected from earth ground.

6. The method of claim 1, further comprising:

outputting a signal from the microcomputer-based electronic controller system to generate a visible or audible signal to a bathing installation user in response to said electrical detection signal.

7. The method of claim 1 wherein said detecting a condition that the electrical ground is not connected to earth ground comprises:

passing current through a light source connected to the electrical ground;

detecting light generated by the light source; and

providing the electrical detection signal when the light source is not generating light.

8. The method of claim 1, further comprising:

powering the electrically powered circuit by a line voltage connection;

disconnecting the line voltage connection in response to said electrical detection signal.

9. The method of claim 1, wherein the bathing installation includes a spa having a body of water and a system for recirculating the body of water through a heater apparatus.

10. A method for detecting failure in a spa electrical component, comprising:

providing control signals from a microcomputer-based electronic control system to control operation of the spa electrical component electrically powered by line voltage and having an electrical ground connection to earth ground;

monitoring the ground connection to detect current flow between the spa electrical component and earth ground, wherein during operation of the spa electrical component, no current flows between the spa electrical component and earth ground, and the presence of current flow during operation of said spa electrical component indicates a failure of said component;

generating a detector signal indicative of current flow in said electrical connection to earth ground indicative of said failure.

11. The method of claim 10, further comprising:

disconnecting said spa electrical component from line voltage in response to said detector signal indicative of current flow in said electrical connection to ground.

12. The method of claim 11, wherein said disconnecting said spa electrical component includes:

sending a control signal from said microcomputer-based electronic control system to open a relay.

13. The method of claim 11, wherein said electrical component is a heater apparatus for heating water supplied to the spa.

14. The method of claim 13, wherein the heater apparatus has a heater housing fabricated of electrically conductive material and an electric heater element, the electrical connection to ground being connected to said heater housing.

15. The method of claim 10, wherein said monitoring the ground connection to detect current flow comprises:

using a toroid surrounding a wire comprising said ground connection to generate the detection signal when current passes through the wire.

16. A method of testing a ground fault circuit interrupter for a bathing installation, comprising:

supplying a line voltage supply to the bathing installation using at least two power supply conductors;

connecting the line voltage supply to one or more spa devices through one or more switching devices to power the devices;

controlling the one or more switching devices using an electronic controller system;

monitoring current flow in said high power conductors to detect a current imbalance;

disconnecting the line voltage supply to said one or more spa devices when a current imbalance is detected without disconnecting power from said controller system;

during a test conducted on a programmed schedule without user intervention, simulating a fault condition by generating a current imbalance to test said monitoring and said disconnecting;

automatically reconnecting the line voltage to said one or more spa devices immediately following said test if said monitoring and said disconnecting was properly performed during said test.

17. The method of claim 16, further including:

displaying a current imbalance condition message on a control panel display in response to detection of said current imbalance.

18. The method of Claim 16, further including:

in response to a user-command, simulating a fault condition by generating a current imbalance to test said monitoring and said disconnecting;

automatically reconnecting said the line voltage to said one or more spa devices immediately following said test if said monitoring and said disconnecting was properly performed during said test.

19. The method of claim 16, wherein the bathing installation includes a spa having a body of water and a system for recirculating the body of water through a heater apparatus.