Dishwasher appliances and methods for operating appliances

Abstract

Dishwasher appliances and methods for operating appliances are provided. A method includes activating a drain pump to operate at a first speed, and ascertaining a dry drain status for the drain pump after a first speed drain time. The method further includes performing a deactivation routine when the dry drain status is positive, the deactivation routine comprising deactivating the drain pump. The method further includes performing a secondary drain routine when the dry drain status is negative, the secondary drain routine comprising activating the drain pump to operate at a second speed, the second speed greater than the first speed.

What is claimed is: 
     
         1 . A method for operating an appliance, the method comprising:
 activating a drain pump to operate at a first speed;   ascertaining a dry drain status for the drain pump after a first speed drain time;   performing a deactivation routine when the dry drain status is positive, the deactivation routine comprising deactivating the drain pump; and   performing a secondary drain routine when the dry drain status is negative, the secondary drain routine comprising activating the drain pump to operate at a second speed, the second speed greater than the first speed.   
     
     
         2 . The method of  claim 1 , wherein the deactivation routine further comprises continuing operation of the drain pump at the first speed for a first speed extend time, and wherein deactivating the drain pump occurs after continuing operation of the drain pump at the first speed for the first speed extend time. 
     
     
         3 . The method of  claim 1 , wherein the secondary drain routine further comprises ascertaining the dry drain status for the drain pump after a second speed drain time. 
     
     
         4 . The method of  claim 3 , wherein the secondary drain routine further comprises performing a secondary deactivation routine when the dry drain status is positive, the secondary deactivation routine comprising deactivating the drain pump. 
     
     
         5 . The method of  claim 4 , wherein the secondary deactivation routine further comprises continuing operation of the drain pump at the second speed for a second speed extend time, and wherein deactivating the drain pump occurs after continuing operation of the drain pump at the second speed for the second speed extend time. 
     
     
         6 . The method of  claim 3 , wherein the secondary drain routine further comprises continuing operation of the drain pump at the second speed when the dry drain status is negative and repeating the step of ascertaining the dry drain status for the drain pump after a second speed drain time. 
     
     
         7 . The method of  claim 6 , wherein the secondary drain routine further comprises tallying consecutive occurrences of the dry drain status being negative. 
     
     
         8 . The method of  claim 7 , wherein the secondary drain routine further comprises disabling activation of the drain pump at the first speed when the tally of consecutive occurrences is greater than or equal to a consecutive occurrence threshold. 
     
     
         9 . The method of  claim 6 , wherein the secondary drain routine further comprises resetting the tally of consecutive occurrences when a positive dry drain status occurs. 
     
     
         10 . A dishwasher appliance, comprising:
 a tub that defines a wash chamber for receipt of articles for washing;   a sump for collecting fluid from the wash chamber;   a fluid circulation assembly in fluid communication with the sump, the fluid circulation assembly comprising a drain pump; and   a control unit in communication with the drain pump, the control unit operable for:
 activating the drain pump to operate at a first speed; 
 ascertaining a dry drain status for the drain pump after a first speed drain time; 
 performing a deactivation routine when the dry drain status is positive, the deactivation routine comprising deactivating the drain pump; and 
 performing a secondary drain routine when the dry drain status is negative, the secondary drain routine comprising activating the drain pump to operate at a second speed, the second speed greater than the first speed. 
   
     
     
         11 . The dishwasher appliance of  claim 10 , wherein the deactivation routine further comprises continuing operation of the drain pump at the first speed for a first speed extend time, and wherein deactivating the drain pump occurs after continuing operation of the drain pump at the first speed for the first speed extend time. 
     
     
         12 . The dishwasher appliance of  claim 10 , wherein the secondary drain routine further comprises ascertaining the dry drain status for the drain pump after a second speed drain time. 
     
     
         13 . The dishwasher appliance of  claim 12 , wherein the secondary drain routine further comprises performing a secondary deactivation routine when the dry drain status is positive, the secondary deactivation routine comprising deactivating the drain pump. 
     
     
         14 . The dishwasher appliance of  claim 13 , wherein the secondary deactivation routine further comprises continuing operation of the drain pump at the second speed for a second speed extend time, and wherein deactivating the drain pump occurs after continuing operation of the drain pump at the second speed for the second speed extend time. 
     
     
         15 . The dishwasher appliance of  claim 12 , wherein the secondary drain routine further comprises continuing operation of the drain pump at the second speed when the dry drain status is negative and repeating the step of ascertaining the dry drain status for the drain pump after a second speed drain time. 
     
     
         16 . The dishwasher appliance of  claim 15 , wherein the secondary drain routine further comprises tallying consecutive occurrences of the dry drain status being negative. 
     
     
         17 . The dishwasher appliance of  claim 16 , wherein the secondary drain routine further comprises disabling activation of the drain pump at the first speed when the tally of consecutive occurrences is greater than or equal to a consecutive occurrence threshold. 
     
     
         18 . The dishwasher appliance of  claim 15 , wherein the secondary drain routine further comprises resetting the tally of consecutive occurrences when a positive dry drain status occurs. 
     
     
         19 . The dishwasher appliance of  claim 10 , wherein the drain pump is a two-speed drain pump. 
     
     
         20 . The dishwasher appliance of  claim 10 , wherein the fluid circulation assembly further comprises a wash pump.