Control devices and methods for motor home A/C systems

A control device for use in combination with the electrical system supplied with a motor home air-conditioning (A/C) unit which is supplied with electric current, at least part of the time during its operation, by an internal combustion engine driven generator equipped with a cranking motor for starting said engine, for the automatic control of the starting and stopping of said generator to minimize fuel and energy loss in the cyclic operation of said A/C unit which comprises:

• first means for beginning of the operation of said A/C unit a first predetermined amount of time after the start of the running of said generator comprising a DPDT relay with an on delay of between about 3 to 10 seconds,
• second means to cause the running of said generator continuously with the operation of said A/C unit and
• third means for discontinuing said running of said generator a second predetermined amount of time after the termination of operation of said A/C unit, and
• temperature sensing means for controlling operation of the A/C unit and starting of said engine,
• whereby upon ambient temperature raising above a predetermined temperature, said generator automatically starts and runs for said first predetermined amount of time before said A/C unit begins to run,
• said generator runs continuously with the running of said A/C unit and
• running of said generator is discontinued a second predetermined amount of time after the termination of said running of said A/C unit caused by said ambient temperature falling below said predetermined tempe ature.

In combination with the electrical system supplied with a motor home air-conditioning (A/C) unit which is supplied with electric current, at least part of the time during its operation, by an internal combustion engine driven generator equipped with a cranking motor for starting said engine, the improvement, whereby upon ambient temperature raising above a predetermined temperature, said generator automatically starts and runs a first predetermined amount of time before said A/C unit begins to run, said generator runs continuously with the running of said A/C unit and running of said generator is discontinued a second predetermined amount of time after the termination of said running of said A/C unit caused by said ambient temperature falling below said predetermined temperature, of a control device for the automatic control of the starting and stopping of said generator to minimize fuel and energy loss in the cyclic operation of said A/C unit which comprises:

• means including a first time delay relay with a delay of between about 3 to 10 seconds for beginning of the operation of said A/C unit a first predetermined amount of time after the start of the running of said generator,
• means including a second time-delay relay for running said generator continuously with the operation of said A/C unit,
• means including a third time-delay relay for discontinuing said running of said generator a second predetermined amount of time after the termination of said operation of said A/C unit,
• temperature sensing means for controlling operation of the A/C unit and starting of said engine,
• a power cord for supplying electrical current to said A/C unit in said motor home from an external power source and
• switch means for automatically disconnecting said power cord from said A/C unit when said generator is running.

An improved method of operating a motor home air-conditioning (A/C) unit which is suppied with electric current, at least part of the time during its operation, by an internal combustion engine driven generator equipped with a cranking motor for starting said engine, to control the starting and stopping of said generator to minimize fuel and energy loss in the cyclic operation of said A/C unit which comprises the following combination of steps:

• automatically starting the running of the generator by a thermostat positioned in said motor home upon ambient temperature raising above a predetermined temperature,
• beginning of the operation of said A/C unit a first predetermined amount of time after the start of the running of said generator,
• running of said generator continuously with the operation of said A/C unit and
• automatically discontinuing said running of said generator a second predetermined amount of time after the termination of operation of said A/C unit caused by said ambient temperature falling below said predetermined temperature.