Spa with Circuit for Detecting and Responding to Excessive Changes in Pump Current

Abstract

A spa heater/control includes sensors and processors to monitor and display indicia of common failures. The heater/control includes voltage sensors and processing to measure proper power connections to the heater/control. The spa heater/control further monitors various voltages, currents, flow rates, and temperatures within the spa to provide diagnostic information which is easily obtained by a spa owner to provide to a spa dealer to reduce the time and cost of spa repairs. In particular, the heater/control compare a present current draw of a spa pump to the expected current draw. A difference exceeding a threshold, may indicate a draw blocked by, for example, a small child, and the pump is turned off.

1 . A method for controlling a spa, the method comprising:
 measuring a normal current draw of a spa pump;   storing the measured current draw;   measuring the present current draw of the spa pump;   comparing the stored current draw to the present current draw of the spa pump; and   controlling spa elements to prevent damage associated with a low spa pump flow rate indicated by a low current draw.   
   
   
       2 . The method of  claim 1 , wherein controlling spa elements to prevent damage associated with a low spa pump flow rate comprises turning the spa pump off to prevent damage if the present current draw is substantially less than the stored current draw. 
   
   
       3 . The method of  claim 2 , wherein turning the spa pump off if the present current draw is substantially less than the stored current draw comprises turning the spa pump off if the present current draw is approximately 40 percent less than the stored current draw. 
   
   
       4 . The method of  claim 1 , wherein controlling spa elements to prevent damage associated with a low spa pump flow rate comprises preventing turning the spa heater to “ON” when the spa pump flow rate is low, thereby preventing damage to the heater when the flow rate is low. 
   
   
       5 . The method of  claim 1 , wherein controlling spa elements to prevent damage associated with a low spa pump flow rate comprises:
 converting the present spa pump current to a present spa pump flow rate;   displaying the present spa pump flow rate on a digital display;   observing the displayed present spa pump flow rate; and   turning off the spa pump if the displayed present spa pump flow rate is low.   
   
   
       6 . A method for controlling a spa, the method comprising:
 measuring a normal current draw of a spa pump;   storing the measured current draw;   measuring the present current draw of the spa pump;   comparing the stored current draw to the present current draw of the spa pump; and   preventing turning the spa heater to “ON” when the present current draw of the spa pump is substantially lower than the stored current draw, thereby preventing damage to the heater when a spa pump flow rate is low.   
   
   
       7 . A method for controlling a spa, the method comprising:
 measuring a normal current draw of a spa pump;   storing the measured current draw;   measuring the present current draw of the spa pump;   comparing the stored current draw to the present current draw of the spa pump; and   turning the pump off to prevent damage if the present pump flow rate is substantially less than the stored pump flow rate.