Что касается system schematic, изначально ведь вопрос был не по эл. проводке?
То
A. System Schematic Layout
The system schematics use a standard modular format. Power sources are shown on the left with power flow going to the right, followed by controls, system then EICAS (Engine Indicating and Crew Alerting System).
Systems are isolated into system 1/left/pilot, system 2/right/copilot and if required system 3/center.
If isolated systems are shown on one sheet, then system1/left/pilot is shown on the bottom, system 2/right/copilot is shown on the top, and if required system 3/center is shown in the middle.
If isolated systems are shown on separate sheets, then system1/left/pilot is shown on sheet 1, system2/right/copilot is shown on sheet 2, and if required system 3/center is shown on sheet 3.
B. LRU and ILRU Description
Line Replaceable Units (LRU) are outlined with thick solid lines. A LRU is shown complete with all of its connections on its home system. Splitting of LRU's will be held to a minimum. When splitting is necessary, it is shown by a thick solid zig-zag that is placed at the top of a LRU, and is called a Z-break.
Interfacing Line Replaceable Units (ILRU) are outlined with thin solid lines, and surrounded by a dashed line with the title and chapter reference to its home system. LRU's that interface with another system will be shown on the interfacing system as an ILRU. The ILRU will show the part of the LRU that connects to the interfacing system.
C. Redundant and Reversionary Systems
Some systems can send digital data over dual redundant LRU's that contain dual redundant microprocessors, and over dual redundant digital databusses. Reversionary controllers (EICAS control panel and reversion control panel) can switch digital data through different DAU's (Data Acquisition Unit), IAC's (Integrated Avionics Computer) and DU's (Display Units).
To simplify the system schematics, ILRU's that interface with other ILRU's will show only the digital data paths that are used when redundant and reversionary systems are in normal mode. Digital data paths from a LRU to an ILRU will be shown in their entirety. To find the other possible data paths when redundant and reversionary systems are not in normal mode, refer to the home system of the ILRU. and т.д.