Two speed control for mobile refrigeration generators
AssigneeCarrier Corporation
InventorsJohn T. Steele, Peter P. Guzman, Jeffrey J. Burchill, Martin Murphy Mertell, Douglas R. Auyer, Cheryl M. Keiling
Life of this patent
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Abstract
A current sensor is installed in a generator set to measure the current being delivered from the generator set to a refrigeration unit. A control is responsive to the current transformer to reduce the speed of the drive engine to a lower speed when the current being delivered to the refrigeration unit is determined to be below a predetermined higher level. Provision is made to override the system when the sensed current is determined to be transient caused or in the event that ambient temperature is determined to be above a predetermined temperature threshold.
Claims11
A method of controlling the speed of a drive mechanism for a generator supplying electrical power to components of a refrigeration system, comprising the steps of:
- establishing a predetermined high threshold level of current as an indication of load in the generator;
- sensing the level of current being delivered by the generator to the refrigeration system;
- when the sensed level is equal to or below said predetermined high threshold, reducing the speed of said drive mechanism to a lower level;
- and
- initiating a timer and, if the sensed current condition does not persist for a predetermined period of time, determining that it was transient caused and preventing the changing of speed for that reason.
An apparatus for controlling the speed of a drive mechanism for a generator supplying electrical power to components of a refrigeration system comprising:
- a current sensing device installed in a circuit between the generator and the refrigeration system for sensing the current being delivered to the refrigeration system;
- and
- a control responsive to said current sensing device for reducing the speed of said drive mechanism when the sensed current level is determined to be below a predetermined upper threshold, wherein said control is adapted to initiate a timer and, if the sensed current condition does not persist for a predetermined period of time, determining that it was transient caused and preventing the changing of speed for that reason.
Dependencies are inferred from the claim text.