The Ambient ATS is a thermistor type sensor with a variable resistance that produces an analog signal between 0 and 5 V, representing the temperature of the ambient air. The Ambient ATS is used with the Idle Shutdown Timer, specifically for the Ambient Air Temperature Override Disable feature. See Figure 3-46 and see Figure 3-47.
This option allows the override to be disabled based on ambient air temperature. Although DDEC can calculate ambient air temperature, an Ambient ATS should be installed. If the upper and lower temperature limits are set and the ambient temperature is within the specified limits, the override will be disabled and the engine will be shutdown after the specified time limit is met. To disable this feature, the upper and lower limits must be set to 167 F (75 C).
The installation of an Ambient ATS is recommended if the Ambient Air Temperature Override Disable feature is enabled. Install the Ambient ATS where ambient air temperature can be read. A protected location on the frame rails where it will not be splattered with dirt and grime, and is removed from any heat source such as exhaust, is preferred.