20-33-20 Page 1
_____________________________________________
ROUTES DEFINITION - DESCRIPTION AND OPERATION
_______
1. General
For safety reasons and to prevent possible electro-magnetic interference
(EMI), the electrical and optical cables are installed in physically
separated routes.
These routes consist of cables grouped together according to the nature of
cables and the type of signal.
The routes are identified by a letter code.
_________________________________________
2. Allocation of electrical cables to routes
A. Generation: G Route G includes cables linked to electrical power services such as Integrated Drive Generator (IDG), Auxiliary Power Unit (APU), battery, external power and RAT feeders.
B. Generator excitation route: E
This group of cables is installed together with route G.
C. Power supply route (C/B rating > 15A): P Route P includes power lines protected by a circuit breaker with a rating equal to or more than 15A.
D. Miscellaneous route (C/B rating < 15A): M Route M includes AC or DC supply cables protected by a circuit breaker with a rating less than 15A, ARINC buses, high-level analog signals (> 12V), maximum voltage permissible: 115VAC.
____
NOTE : As a general rule, data bus cables (i.e. ARINC 429) shall be in route M, but, if necessary for separation purposes, some ARINC 429 cables can be routed in route S.
____
NOTE : This route includes monitoring cables related to EFCS and auto flight systems.
____
NOTE : Major cables identified with an "S" directly on the cable or with black print on a pink sleeve are routed in routes M and S.
E. Sensitive route: S
Route S includes cables sensitive to interference such as low level
analog signals, etc.
Maximum voltage permissible: 28VDC.
____
NOTE : Auto flight and EFCS control cables shall be included in this route for segregation purposes.
20-33-21 Page 1
They shall not cause interference with other sensitive cables in this route.
____
NOTE : Major cables identified with an "S" directly on the cable or with black print on a pink sleeve are routed in routes M and S.
F. Audio route: R Route R includes analog audio lines and specific routings in order to avoid interference (e.g. sensitive to 400HZ).
G. Routes for coaxial cables: T, U, V
These routes are reserved for coaxial cables.
H. Fuel quantity system route (A340-500/600 only): Q Route designed to prevent electrical interference and short circuits with other categories of routes.
J. Specific routes (A300 only)
(1)
Auto-flight route: A Route A includes cables for the control and monitoring of the automatic flight systems.
(2)
Radio COM and NAV control: C Route C includes power supply lines for analog systems and control lines for radio communication (COM) and navigation (NAV).
(3)
Provision for special circuit (system 1 and 2): H
Route reserved for special system.
(4)
Traffic alert and Collision Avoidance System (TCAS): SG
Route reserved for cables related to the TCAS system.
(5)
Navigation system (coaxial cable): U Route reserved for the OMEGA 1 and 2 systems with coaxial cables.
___________________
3. Routes by programme The tables that follow give on the different types of aircraft the route codes used to identify the harnesses. (Ref. Fig. 001, 002, 003)
20-33-21 Page 2
Routes Definition - Harnesses Identification
Figure 001
20-33-21 Page 3
Routes Definition - Harnesses Identification
Figure 002
20-33-21 Page 4
Routes Definition - Harnesses Identification
Figure 003
20-33-21 Page 5
______________________________________________________
SEPARATION / ROUTING RULES - DESCRIPTION AND OPERATION
_______
1. General
The main purpose of the separation/routing rules is to prevent:
-electro-magnetic interference between cables,
-physical damage to the Electrical Wiring Installation System (EWIS),
-simultaneous failure of redundant systems.
There are two types of separation:
-
Physical distance: . between the wiring of redundant systems (systems 1 and 2), . between independent power sources and routes, . between the harnesses and adjacent non-electrical systems. (For more information, refer to chapter: Wiring - 20-33-1X)
中國航空網 m.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：A320 ESPM Electrical Standard Practices Manual 2(50)
