Fill protection algorithm

• US 8,480,811 B2
• Filed: 05/17/2011
• Issued: 07/09/2013
• Est. Priority Date: 05/17/2010
• Status: Expired due to Fees

• Current Assignee: Viking Range Corporation (Middleby Corporation)
• Original Assignee: Viking Range Corporation (Middleby Corporation)
• Inventors: King, Jonathan Duane
• Primary Examiner(s): Carrillo, Bibi
• Application Number:
  US13/109,321
• Publication Number:
  US 20110277794A1
• Time in Patent Office: 784 Days
• Field of Search: 134/18, 134/19, 134/25.2, 134/42, 134/56.D, 134/57.D, 134/58.D, 134/184, 134/186
• US Class Current: 134/18
• CPC Class Codes: A47L 15/0023 Water filling A47L15/4244 takes precedence
• CPC Class Codes: A47L 2401/09 Water level
• CPC Class Codes: A47L 2401/12 Water temperature
• CPC Class Codes: A47L 2501/02 Water discharge, e.g. opening or closure of discharge valve
• CPC Class Codes: A47L 2501/05 Drain or recirculation pump, e.g. regulation of the pump rotational speed or flow direction
• CPC Class Codes: A47L 2501/26 Indication or alarm to the controlling device or to the user
• CPC Class Codes: A47L 2501/32 Stopping or disabling machine operation, including disconnecting the machine from a network, e.g. from an electrical power supply

Abstract

A fill protection algorithm for determining whether the water level in a dishwasher is sufficient to enable operation of the wash pump of the dishwasher without burn-out or other damage to the wash pump and/or heating element of the dishwasher due to insufficient water level. A change in water temperature TEMP_DELTA is detected and is compared to a predetermined water temperature change level or amount, TEMP_MIN—DELTA, and if the detected change in water temperature TEMP_MIN—DELTA is greater than or equal to the minimum water temperature change TEMP_MIN—DELTA, operation of the dishwasher is allowed to proceed.

Claims

1. A method of controlling operation of a dishwasher, comprising

determining a minimum change in temperature of water within the dishwasher, TEMP_MIN—

_DELTA, indicative of a level of water present in the dishwasher to initiate operation of a wash pump thereof;

initiating a fill sequence for filling the dishwasher with water for operation of the dishwasher;

monitoring a change in temperature, TEMP_DELTA, of the water within the dishwasher during the fill sequence;

comparing the TEMP_DELTA to the TEMP<sub>MIN—

DELTA</sub>;

if the TEMP_DELTA is greater than or equal to the TEMP<sub>MIN—

DELTA</sub>, initiating operation of the wash pump; and

if the TEMP_DELTA is less than the TEMP<sub>MIN—

DELTA</sub>, initiating a drain sequence for the dishwasher.

2. The method of claim 1 and further comprising:

initiating a retry fill sequence after completion of the drain sequence,

monitoring a change in temperature, TEMP_DELTA, of the water within the dishwasher;

comparing the TEMP_DELTA to the TEMP<sub>MIN—

DELTA</sub>;

if the TEMP_DELTA is greater than or equal to the TEMP<sub>MIN—

DELTA</sub>, initiating operation of the wash pump; and

if the TEMP_DELTA is less than the TEMP<sub>MIN—

DELTA</sub>, initiating a drain sequence for the dishwasher.

3. The method of claim 1 and wherein after initiating operation of the wash pump, monitoring a current flow in a motor of the wash pump to determine whether a sufficient flow of water is passing through the wash pump for continued operation thereof without damage to the wash pump.

4. The method of claim 1 and wherein monitoring a change in temperature, TEMP_DELTA, of the water in the dishwasher comprises detecting a first temperature of the water prior to initiating the fill sequence, and detecting a second temperature after initiation of the fill sequence.

5. The method of claim 1 and further comprising monitoring a change in temperature during the drain sequence to detect presence of water, and if water is detected, initiating a second fill sequence and begin operation of the wash pump.

6. The method of claim 2 and further comprising terminating operation of the dishwasher if the TEMP_DELTA is less than the TEMP_MIN—

_DELTA after initiating the retry fill sequence, and indicating an error condition.

7. The method of claim 4 and wherein the second temperature is detected after a conclusion of the fill sequence.

8. The method of claim 4 and wherein the first temperature comprises a minimum monitored temperature of the water, and the second temperature comprises a maximum monitored temperature of the water detected after a conclusion of the fill sequence.

9. The method of claim 5 and wherein if water is not detected during the drain sequence, terminating operation of the dishwasher and indicating an error condition.

10. The method of claim 5 and wherein after initiating operation of the wash pump, monitoring a current flow in a motor of the wash pump to determine whether a sufficient flow of water is passing through the wash pump for continued operation thereof without damage to the wash pump.

11. A method of controlling operation of a dishwasher, comprising

determining a minimum change in temperature of water within the dishwasher, TEMP_MIN—

_DELTA, indicative of a level of water present in the dishwasher to initiate operation of a wash pump thereof;

initiating a fill sequence for filling the dishwasher with water for operation of the dishwasher;

monitoring a change in temperature, TEMP_DELTA, of the water within the dishwasher during the fill sequence;

comparing the TEMP_DELTA to the TEMP<sub>MIN—

DELTA</sub>;

if the TEMP_DELTA is greater than or equal to the TEMP<sub>MIN—

DELTA</sub>, initiating operation of the wash pump;

if the TEMP_DELTA is less than the TEMP<sub>MIN—

DELTA</sub>, initiating a drain sequence for the dishwasher;

as the water is drained, monitoring a change in temperature of the water draining during the drain sequence; and

if the monitored change in temperature of the water drained during the drain sequence is greater than or equal to the minimum change in temperature TEMP<sub>MIN—

DELTA</sub>, completing the drain sequence and initiating a second fill sequence for operation of the dishwasher.

12. The method of claim 11 and wherein:

if the monitored change in temperature of the water drained during the drain sequence is less than the minimum change in temperature TEMP<sub>MIN—

DELTA</sub>, completing the drain sequence;

initiating a retry fill sequence after completion of the drain sequence,

monitoring a change in temperature, TEMP_DELTA, of the water within the dishwasher;

comparing the TEMP_DELTA to the TEMP<sub>MIN—

DELTA</sub>;

if the TEMP_DELTA is greater than or equal to the TEMP<sub>MIN—

DELTA</sub>, initiating operation of the wash pump; and

if the TEMP_DELTA is less than the TEMP<sub>MIN—

DELTA</sub>, initiating a drain sequence for the dishwasher.

13. The method of claim 11 and wherein after initiating operation of the wash pump, monitoring a current flow in a motor of the wash pump to determine whether a sufficient flow of water is passing through the wash pump for continued operation thereof without damage to the wash pump.

14. The method of claim 12 and further comprising terminating operation of the dishwasher if the TEMP_DELTA is less than the TEMP_MIN—

_DELTA after initiating the retry fill sequence, and indicating an error condition.