System and method for freight refrigeration power control
View Patent ↗A mobile refrigerator unit is operated remotely via wireless technology using a system with a local maintenance switch. A local override switch turns the refrigerator unit on and off, but keeps it on in the event of failure of the maintenance switch.
1. A mobile refrigeration system, comprising:
a car;
a refrigeration unit in said car and having a plurality of operating conditions including temperature;
a refrigeration-unit-energizing power source in said car that is connected to and provides power to the refrigeration unit;
a refrigeration-unit operation unit controller in said car;
a remote operating-condition manager coupled to said operation unit controller, and located at a remote station remote from said car, that sends remote control commands to the car;
a local switch that is connectable in series between the power source and the refrigeration unit;
a power relay control connected in series between the local switch and the refrigeration unit;
an on-off maintenance switching arrangement connected in series between said operation unit controller and said power relay control;
wherein:
the power relay control selectively: a) connects and enables the local switch; and b) bypasses and disables the local switch;
while the local switch is connected and enabled:
when the local switch is in an on configuration, the power source provides power to the refrigeration unit;
when the local switch is in an off configuration, the power source does not provide power to the refrigeration unit;
the power relay control, if and only if the on-off maintenance switching arrangement is in an on configuration, receives the remote control commands;
while the local switch is bypassed and disabled:
the provision of the power source to the refrigeration unit is not affected by the local switch; and
the power relay control, if and only if the on-off maintenance switching arrangement is in an on configuration: i) receives the remote control commands, and ii) connects and disconnects the power source and the refrigeration unit in response to the remote control commands.
2. The system according to claim 1 , further comprising:
a maintenance switch monitor that provides a status of the maintenance switch to the remote station.
3. The system according to claim 1 , further comprising:
an antenna associated with the car that receives the remote control commands.