CARRIER 4S5980 - Caterpillar

Stopping the engine immediately after the engine has been working under load, can result in overheating and accelerated wear of the engine components.Avoiding hot engine shutdowns will maximize turbocharger shaft and bearing life. Also, selective catalytic reduction component life.
Note: Individual applications will have different control systems. Ensure that the shutoff procedures are understood. Use the following general guidelines to stop the engine.
Remove the load from the engine. Reduce the engine speed to low idle. Allow the engine to idle for 5 minutes to cool the engine.
Stop the engine after the cool down period according to the shutoff system on the engine and turn the ignition keyswitch to the OFF position. If necessary, refer to the instructions that are provided by the OEM.
Disconnecting the battery power too soon may prevent purging of the DEF fluid lines after the engine is shut down. Refer to this Operation and Maintenance Manual, "Battery Disconnect Switch" for more information.