Shutoff system for pool or spa
View Patent ↗A control system for a bathing installation which has one or more electrically powered devices. A line voltage service is connected through a GFCI to power the electrically powered devices, the GFCI adapted to interrupt the service upon detection of a ground fault. A trip circuit may induce a ground fault and trip the GFCI in response to a trip signal, thereby disabling application of electrical power to the electrically powered devices. An electronic circuit is responsive to a fault condition for generating the trip signal.
1. A method for controlling a bathing installation, comprising:
sensing a water temperature of water in a bathing installation tub or a recirculating water flow path for the bathing installation;
starting a timer when said sensed water temperature equals a first predetermined temperature threshold;
stopping and resetting the timer if said water temperature falls to a second predetermined temperature threshold which is less than said first threshold;
entering a fault mode if:
said sensed water temperature has risen by a first temperature increment within a first preceding time interval since the timer was started, and is now equal to or greater than a third predetermined threshold which is greater than said first threshold.
2. A method for controlling a spa, comprising:
sensing a water temperature of water in a spa tub or a recirculating spa water flow path;
starting a timer when said sensed water temperature equals a first predetermined temperature threshold;
stopping and resetting the timer if said water temperature falls to a second predetermined temperature threshold which is less than said first threshold;
entering a fault mode if said sensed water temperature has risen by a second temperature increment since said timer was last started, and is now equal to or greater than a fourth predetermined threshold which is greater than said third threshold.
3. A method for controlling a spa, comprising:
sensing a water temperature of water in a spa tub or a recirculating spa water flow path;
starting a timer when said sensed water temperature equals a first predetermined temperature threshold;
stopping and resetting the timer if said water temperature falls to a second predetermined temperature threshold which is less than said first threshold;
entering a fault mode if said sensed water temperature has risen by a third temperature increment since said timer was last started, and is now greater than or equal to said fourth predetermined threshold, and said timer has been running for at least a second preceding time interval.
4. The method of claim 3 , wherein said fault mode includes setting a fault flag in a nonvolatile memory.
5. The method of claim 3 , further comprising performing a disable function after setting said default flag to disable power from said spa.
6. The method of claim 5 , wherein said performing a disable function comprises:
inducing a ground fault to trip a ground fault circuit interrupter circuit.
7. A method for controlling a spa, comprising:
sensing a water temperature of water in a spa tub or a recirculating spa water flow path;
starting a timer when said sensed water temperature equals a first predetermined temperature threshold;
stopping and resetting the timer if said water temperature falls to a second predetermined temperature threshold which is less than said first threshold;
entering a fault mode if:
(i) said sensed water temperature has risen by a first temperature increment within a first preceding time interval since the timer was started, and is now equal to or greater than a third predetermined threshold which is greater than said first threshold;
(ii) said sensed water temperature has risen by a second temperature increment since said timer was last started, and is now equal to or greater than a fourth predetermined threshold which is greater than said third threshold; or
(iii) said sensed water temperature has risen by a third temperature increment since said timer was last started, and is now greater than or equal to said fourth predetermined threshold, and said timer has been running for at least a second preceding time interval.
8. The method of claim 7 , wherein said fault mode includes setting a fault flag in a nonvolatile memory.
9. The method of claim 8 , further comprising performing a disable function after setting said default flag to disable power from said spa.
10. The method of claim 9 , wherein said performing a disable function comprises:
simulating a ground fault to trip a ground fault circuit interrupter circuit.
11. A method for monitoring and controlling operation of a spa installation including a spa vessel for holding water, a line voltage electrical supply, an electronic controller, a ground fault interrupt circuit (GFCI), a water heater system and a pump for recirculating water through a recirculating water flow path, comprising:
sensing a stoppage or restricted flow in the water flow path;
inducing a ground fault to trip the GFCI to interrupt power to the pump.
12. The method of claim 11 , wherein said sensing a stoppage or restricted flow in the water flow path comprises:
monitoring an electrical output signal from a pressure sensor mounted to sense a water pressure in the water flow path.
13. The method of claim 1 , wherein said sensing a water temperature comprises sensing a water temperature in a recirculating water flow path, and comprises:
activating a water pump to circulate water from the tub through the water flow path past a temperature sensor so that the temperature sensor is sensing water temperature indicative of water temperature in the tub.
14. The method of claim 13 , wherein said activating a water pump is performed during a filter cycle conducted periodically, to pass water through a filter connected in the recirculating water flow path without activating a water heater.
15. The method of claim 14 , further comprising:
activating a filter cycle on a predetermined periodic schedule even in the event the bathing installation is in a sleep or an economy mode.
16. The method of claim 13 , wherein the temperature sensor is located in the water recirculation path adjacent an input to a water heater in the path.
17. The method of claim 1 , wherein said fault mode comprises performing a disable function to disable power from said spa.
18. The method of claim 2 , wherein said entering said fault mode includes declaring a stuck relay condition.
19. The method of claim 18 , wherein said fault mode further comprises starting a disable algorithm in a bathing installation electronic controller to trip a ground fault circuit interrupter to disable power to the bathing installation.
20. The method of claim 3 , wherein said sensing a water temperature comprises sensing a water temperature in the recirculating water flow path, and comprises:
activating a water pump to circulate water from the tub through the water flow path past a temperature sensor so that the temperature sensor is sensing water temperature indicative of water temperature in the tub.