DC ESSENTIAL & NORMAL GENERATION SWITCHING - DESCRIPTION AND OPERATION

** ON A/C NOT FOR ALL

1. General
These circuits control the supply of DC normal busbars and DC essential busbars.
They enable:

their normal supply in normal flight configuration,
automatic transfer in some failure conditions.

** ON A/C NOT FOR ALL

2. Component Location

DC Essential & Normal Generation Switching - Component Location ** ON A/C NOT FOR ALL

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FIN ! FUNCTIONAL DESIGNATION ! PANEL ! ZONE ! ACCESS ! ATA

! ! ! ! DOOR ! REF.

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20PC1 FUSE 120VU 212 24-35-00

FIN	FUNCTIONAL DESIGNATION	PANEL	ZONE	ATA REF
** ON A/C ALL
1PC1	CNTOR-DC NORM BUS 1 SWITCHING	120VU	212	24-35-55
1PC2	CNTOR-DC NORM BUS 2 SWITCHING	120VU	212	24-35-55
4PC	CNTOR-DC ESS BUS SUPPLY	106VU	125	24-35-55
** ON A/C NOT FOR ALL
20PC	HOLDER-FUSE	120VU	212	24-35-00

** ON A/C NOT FOR ALL

3. Operation/Control and Indicating

A. DC NORM BUS SWITCHING Contactor Control (1PC1 and 1PC2)

DC NORM BUS SWITCHING Contactor Control - Simplified Logic

Contactor 1PC1 is supplied in normal configuration and when a TR is lost.
Contactor 1PC2 is supplied when a TR is lost or in case of DC NORM BUS 1 SWITCHING contactor (1PC1) failure.

NOTE: There is an electric interlock between contactors 1PC2 and 4PC to inhibit coupling between busbar 2PP and essential busbar 4PP.

B. DC ESS BUS SPLY Contactor Control (4PC)

DC ESS BUS SPLY Contactor Control - Simplified Logic

Contactor 4PC supplies DC ESS BUS 4PP via BAT BUS 3PP if normal DC busbars 1PP and 2PP are not coupled (electrical interlock between contactors 1PC2 and 4PC).
DC ESS BUS SPLY contactor (4PC) opens when a normal TR is lost (coupling of busbars 1PP and 2PP), in emergency conditions or when the DC NORM BUS 1 SWITCHING contactor (1PC1) is lost.

[Rev.10 from 2021] 2026.03.31 23:23:35 UTC