Manual

1. System Overview

031-132-B0-001 Rev. A

1.5 Generator Modes of Operation, continued

1.5.4. Normal APU Shutdown

The ECM will initiate a normal APU shutdown when AC line is qualified, DC

bus alarm is not active, the 12 minute cool-down period has elapsed, and the

Engine Run command is not active. Otherwise, the ECM will continue to run the

APU until the above conditions are met or a major alarm occurs. Also, the APU

will run for a minimum of 30 minutes if started due to low DC Bus voltage.

1.5.5. Abnormal APU Shutdown

The ECM will immediately shutdown the APU under the following conditions:

 Major alarm

 Activation of manual engine stop switch

 Receipt of software engine stop command

 General generator failure

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Table 1-1 Normal Mode Crank Cycle