| 摘要 |
A detection mechanism for monitoring airflow in an electronics enclosure that has an interior space cooled with forced ambient air, includes a first thermal sensor positioned proximate the enclosure for measuring an ambient air temperature. A second thermal sensor is positioned proximate an exit air stream of the enclosure for measuring the temperature of air that is heated by the electronics in the enclosure. A control circuit is coupled with the first and second thermal sensors and is configured for receiving output signals from the thermal sensors and determining a temperature differential between the measured temperatures. The control circuit initiates an alarm when the temperature differential exceeds a setpoint thereby indicating restricted airflow in the enclosure. Other remedial steps might also be taken prior to initiating the alarm. The cabinet ventilation system prevents equipment thermal shutdown, even in the event of restricted airflow by allowing cool ambient air to be drawn into the lower screens, located in the rear of the cabinet by natural convection. This air absorbs heat from the electronics and exits the cabinet through the upper screens, thus providing sufficient cabinet ventilation to prevent the electronics from overheating.
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