not having a common terminal or connection, as
Such wires and cables connect to the ground net-
work of aircraft electrical systems without causing
shown below:
any circuit malfunctions. For electronic systems
1. Wires with the same circuit function having
with interconnecting ground leads, but only one
a common terminal connection or junction
segment actually grounded to structure, N identi-
have the same wire number but different
fies the segment actually grounded to the structure.
segment letters.
2. Phase letter A, B, or C is a suffix on the
2. Beginning with the lowest number, assign
wire identification code. It identifies the phase or
a number to each wire in numerical
wires in the three-phase power ac distribution
sequence, insofar as practical.
systems. The phase sequence is
Wire segment letter. A wire segment is a
3. Phase letter V is a suffix on the cable
identification code. It identifies the ungrounded
conductor between two terminals or connections.
wire or cable in a single-phase system.
The wire segment letter identifies different
4. For thermocouple wire, use the following
conductor segments in a particular circuit. Use a
suffixes:
different letter for wire segments having a
common terminal or connection. Wire segment
CHROM--Chromel
letters are in alphabetical sequence. The letter A
ALML--Alumel
identifies the first segment of each circuit starting
at the power source. If a circuit contains only one
IRON--Iron
wire segment, this wire segment is A. Do not use
CONS--Constantan
the letters I and O as segment letters. Use double
letters AA, AB, AC, etc., when there is more than
COP--Copper
24 segments. Two permanently spliced wires do
Suffix (when required). When using aluminum
not require separate segment letters if the splice
w i r e , add ALUMINUM OR ALUM to the
is for modification or repair.
identification code.
W i r e size number. The wire size number
identifies the size of the wire or cable. For coaxial
CABLE STRIPPING AND HEAT
SHRINKABLE TUBING
cables and thermocouple wires, the wire size
number is not included. For thermocouple wires,
Nearly all wire and cable electrical conductors
a dash (-) is used instead of the wire size number.
have some type of insulation. When making
electrical connections with wire, you must remove
Ground, phase, or thermocouple letter(s).
a part of this insulation, leaving the end of the
1. Ground cable letter N is a suffix to the wire
wire bare. To help you remove insulation, use a
wire and cable stripping tool similar to the one
identification code. It identifies any wire or cable
shown in figure 2-13.
that completes the circuit to the ground network.
Figure 2-13.-Wire stripping method.
