DOOR AS 4362806 - Caterpillar

The maximum turbocharger speed is determined by the fuel rack setting, the high idle speed, the turbine nozzle and the altitude at which the engine is operated. The rack and high idle speed settings have been established to permit the engine to be operated at the altitude marked on the warning plate on the aftercooler. The turbine nozzle is the same for all altitudes, but the engine fuel rack setting and high idle speed vary with altitude. If the fuel rack setting is greater than specified for the altitude at which the engine is being operated or the high idle speed is too high, serious damage or injury due to turbocharger overspeeding may result.The maximum altitude at which the engine may be operated at the present setting is marked on the warning plate on the aftercooler. The governor housing and turbocharger are sealed for your protection. Changes to the turbocharger, fuel rack setting, or high idle speed should be made only by your Caterpillar dealer.The engine can be operated at a lower altitude than marked on the warning plate without danger of turbocharger overspeeding, but with slightly less than maximum performance, however the fuel rack setting must be changed when operating at a lower altitude to get full power. When operated at a higher altitude, the fuel rack setting must be changed by your Caterpillar dealer. After making any changes, the new altitude limit will be marked on the warning plate and the governor housing will be re-sealed for your protection. This will assure you correct settings have been made.IMPORTANT: Consult your Caterpillar dealer before operating at a higher altitude than is marked on the warning plate.