Icemaker control system

Abstract

A control system for an icemaker utilizes a control scheme in which various operating conditions of the icemaker are monitored sand the icemaker is shut down if a fault condition is sensed. In response to detection of the fault condition, steps are taken to actively remove the fault. Restarting of the icemaker is then attempted if sensors indicate that normal continued operation should be possible. The operating conditions sensed include the temperature of refrigerant at an outlet from a condenser, the rate at which a water pan fills with water while water is delivered to it for subsequent delivery to and over an evaporator to freeze the water into ice on the evaporator. and the time required to harvest ice from the evaporator.

Description

[0001] This application claims benefit of provisional application Ser. No. 60 / 455,103, filed Mar. 13, 2003.FIELD OF THE INVENTION [0002] The present invention relates to commercial icemakers, and in particular to control systems therefore. BACKGROUND OF THE INVENTION [0003] Commercial ice making machines are well known in the art and provide for the manufacture of ice in various forms, such as cubed and flaked. Cube type icemakers typically make ice by running a flow of water over a vertically oriented evaporator until ice of a sufficient thickness has formed thereon. When the ice is of harvest size, a hot gas defrosting procedure is typically used to remove the ice from the evaporator. It has long been recognized that icemakers are prone to a variety of malfunction events. In response thereto icemakers were first designed to include different control systems that shut down the icemaker in response to a sensor indicating that a problem exists. Examples of such malfunctions include t...

AI Technical Summary

Benefits of technology

[0007] A water fill rate routine is shown wherein a sensor monitors the rate of filling of a water pan below the evaporator. If the fill rate falls below a predetermined rate, the ice maker shuts off the compressor and the fill valve remains on. Once the rate increases above the predetermined rate or the high level is obtained, the compressor turns on, and the ice maker resumes a normal ice making cycle. If the water fill rate goes below a predetermined low fill rate the ice maker is shut off and water filling is discontinued. In this manner the control of the present invention conserves energy by turning off the compressor if the water fill rate is low but otherwise acceptable. The compressor is then restarted when the water does eventually reach the desired full level.

Problems solved by technology

It has long been recognized that icemakers are prone to a variety of malfunction events.

Examples of such malfunctions include the condenser being too cold or too hot, ice not being successfully harvested from the evaporator, or insufficient water in the water pan.

A problem with the foregoing control approaches is that the restarts simply occur right after the error is sensed or after the predetermined time delays.

Thus, as long as the particular problem that initiated the shut down continues to exist, each restart attempt during that time is futile and can result in a needless waste of water and / or energy.

A further problem with the prior art controls concerns the fact that nothing is done in an attempt to actively remove or clear the problem causing the fault condition.

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