Pump system with dynamic level control

Abstract

A pump having a motor, an inlet port, a discharge port, a fluid sensor, and a controller is provided. The fluid sensor is configured to detect whether a fluid level has risen above a threshold fluid level. The controller is configured to activate the pump in response to the fluid sensor detecting that the fluid level has risen above the threshold fluid level, initiate a shutoff delay timer in response to the fluid sensor detecting that the fluid level has receded below the threshold fluid level, the shutoff delay timer having a shutoff delay time, increase the shutoff delay time if the fluid sensor detects that the fluid level has risen above the threshold fluid level again before the shutoff delay time elapsed, and maintain the shutoff delay time if the fluid sensor detects that the fluid level stayed below the threshold fluid level until the shutoff delay time elapsed.

What is claimed is: 
     
         1 . A pump comprising:
 a motor;   an inlet port;   a discharge port;   a fluid sensor configured to detect whether a fluid level has risen above a threshold fluid level; and   a controller configured to:
 activate the pump in response to the fluid sensor detecting that the fluid level has risen above the threshold fluid level, 
 initiate a shutoff delay timer in response to the fluid sensor detecting that the fluid level has receded below the threshold fluid level, the shutoff delay timer having a shutoff delay time, 
 increase the shutoff delay time if the fluid sensor detects that the fluid level has risen above the threshold fluid level again before the shutoff delay time has elapsed, and 
 maintain the shutoff delay time if the fluid sensor detects that the fluid level stayed below the threshold fluid level until the shutoff delay time has elapsed. 
   
     
     
         2 . The pump of  claim 1 , wherein the shutoff delay timer has a maximum shutoff delay time. 
     
     
         3 . The pump of  claim 2 , wherein the controller is configured to maintain the shutoff delay time when the shutoff delay time is equal to the maximum shutoff delay time, even if the fluid sensor detects that fluid has risen above the threshold fluid level again before the shutoff delay time has elapsed. 
     
     
         4 . The pump of  claim 1 , wherein the controller is configured to shut down the pump when the fluid sensor detects that the fluid level remains below the threshold fluid level until the shutoff delay time has elapsed. 
     
     
         5 . The pump of  claim 4 , wherein the controller is configured to initiate a reset timer after shutting down the pump, the reset timer having a reset time. 
     
     
         6 . The pump of  claim 5 , wherein the controller is configured to reset the shutoff delay time to a default shutoff delay time if the fluid level remains below the threshold fluid level until the reset time has elapsed. 
     
     
         7 . The pump of  claim 6 , wherein the reset time is reset to a default reset time each time the shutoff delay time is reset to the default shutoff delay time. 
     
     
         8 . The pump of  claim 5 , wherein the reset time is increased each time the shutoff delay time is increased. 
     
     
         9 . The pump of  claim 8 , wherein the reset time is increased in proportion to the shutoff delay time each time the shutoff delay time is increased. 
     
     
         10 . A pump comprising:
 an inlet port;   a discharge port;   a fluid sensor configured to detect a fluid; and   a controller configured to:
 activate the pump in response to the fluid sensor detecting the fluid, 
 after activating the pump, initiate a shutoff delay timer having a shutoff delay time when the fluid sensor no longer detects the fluid, 
 increase the shutoff delay time if the fluid sensor detects the fluid before the shutoff delay time has elapsed, and 
 maintain the shutoff delay time if the fluid sensor does not detect the fluid before the shutoff delay time has elapsed. 
   
     
     
         11 . The pump of  claim 10 , wherein the fluid sensor is a provided in the form of a plurality of electrodes. 
     
     
         12 . The pump of  claim 11 , wherein the plurality of electrodes is provided as only two electrodes. 
     
     
         13 . The pump of  claim 10 , wherein the controller is configured to initiate a startup delay timer having a startup delay time when the fluid sensor detects the fluid and delay activation of the pump until after the startup delay time has elapsed. 
     
     
         14 . The pump of  claim 10 , wherein the controller is configured to shut down the pump if the fluid sensor does not detect the fluid before the shutoff delay time has elapsed. 
     
     
         15 . A method of controlling a level of fluid with a pump having a motor, an inlet port, a discharge port, and a fluid sensor configured to detect a fluid, the method comprising:
 activating the pump in response to the fluid sensor detecting the fluid;   initiating a shutoff delay timer when the fluid sensor no longer detects the fluid, the shutoff delay timer having a shutoff delay time;   increasing the shutoff delay time if the fluid sensor detects the fluid before the shutoff delay time has elapsed; and   maintaining the shutoff delay time if the fluid sensor does not detect the fluid before the shutoff delay time has elapsed.   
     
     
         16 . The method of  claim 15 , further comprising shutting down the pump if the fluid sensor does not detect the fluid before the shutoff delay time has elapsed. 
     
     
         17 . The method of  claim 16 , further comprising initiating a reset timer after shutting down the pump, the reset timer having a reset time. 
     
     
         18 . The method of  claim 17 , further comprising resetting the shutoff delay time to a default shutoff delay time if the fluid sensor does not detect the fluid before the reset time has elapsed. 
     
     
         19 . The method of  claim 18 , further comprising initiating a startup delay timer having a startup delay time when the fluid sensor detects the fluid after the shutoff delay time is reset. 
     
     
         20 . The pump of  claim 19 , further comprising delaying activation of the pump until after the startup delay time has elapsed.