ELECTRICAL
AIRPLANE
OPERATIONS
MANUAL
2-05-10
Page
6D
Code
01
REVISION 26
ABNORMAL OPERATION - CONFIGURATION 3B
Electrical essential transfer failure:
An electrical essential transfer failure will occur when all GLCs and
ALC are open (loss of all generators) and DC BUS 1 and/or DC
BUS 2 remain energized.
The DC BUS 1 may remain energized because:
− BTC 1 fails to open.
− BC 1 fails to open or;
− EBC 1 fails to close.
The DC BUS 2 may remain energized because:
− BTC 2 fails to open or;
− EBC 2 fails to close.
Case 1 - Loss of all generators and BTC 1 is closed (DC BUS 1 is
energized):
− ELEC ESS XFR FAIL warning message on the EICAS.
− All GLCs and ALC are open.
− BTC 2, BC 1, SBC 1 and SBC 2 are open.
− EBC 1, EBC 2, BTC 1, BC 2, BBC and EIC are closed.
NOTE: BC 2 remains closed to keep the CENTRAL DC BUS
energized and making it possible to perform an APU start.
Case 2 - Loss of all generators and BTC 2 is closed (DC BUS 2 is
energized):
− ELEC ESS XFR FAIL warning message on the EICAS.
− All GLCs and ALC are open.
− BTC 1, BC 1, SBC 1 and SBC 2 are open.
− EBC 1, EBC 2, BTC 2, EIC and BC 2 are closed.
NOTE: BC 2 remains closed to keep the CENTRAL DC BUS
energized and making it possible to perform an APU start.
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