Electrical Cables & Connectors

Vocabulary flashcards covering electrical cable definitions, construction materials, classification systems, and environmental requirements based on aircraft engineering principles.

Cable

Two or more wires that are insulated separately within the same outer diameter.

Wire

An isolated single solid conductor or stranded conductor surrounded by insulation.

Wet Arc Tracking

A requirement formulated to assess the resistance to failure of cables when subjected to a combination of insulation damage and fluid contamination.

Normal Current Rating

The amount of current a cable will carry without sustaining a temperature rise sufficient to cause the value of insulation resistance to deteriorate to an unacceptable level, or without exceeding a specified voltage drop.

Aluminium Specific Electrical Resistance

The resistance value of aluminium, which is $2.8\,\mu\Omega/cm$, approximately $1.6$ times higher than copper.

Copper Specific Electrical Resistance

The resistance value of copper, which is $1.73\,\mu\Omega/cm$.

Copper Specific Mass

The mass of copper, which is $8.9\,g/cm^3$, approximately $3.3$ times higher than aluminium.

Aluminium Specific Mass

The mass of aluminium, which is $2.7\,g/cm^3$.

Wire Harness

Multiple insulated wires bound together with lacing tape, metal bands, or another form of restriction used to connect electrical components.

Nyvin

A general-purpose white airframe cable used since the early days of aircraft, available in forms like Uninyvin, Minyvin, and Trinyvin.

SWAMP Areas

Severe Weather and Moisture Prone areas, including wheel wells, leading/trailing edge flap areas, and engine pylons.

Fireproof Cable

Wires or cables required to operate for fifteen minutes in the event of a fire and used in designated fire zones.

Flexible Airframe Cables (Fire Life)

Cables that maintain essential circuits after a fire with an ultimate life of five minutes at $1100^{\circ}C$ ($2012^{\circ}F$).

Efglas

A high-temperature resistant cable used in engine circuits with a maximum service temperature of $260^{\circ}C$ ($500^{\circ}F$) and a white exterior finish.

Kapton

A series of AWG cables with a high degree of insulation using PTFE sleeving over thin layers of insulation, usually tarnished yellow in color.

Verdigris

A blue-green oxide coating deposit that develops on copper when exposed to atmosphere and moisture, acting as a poor conductor.

Insulation Resistance

The ability of a material to withstand current leakage through and over the surface of the insulation materials.

Dielectric Strength

The ability of a material to withstand a high potential difference, expressed as the voltage at which the material fails and breaks down due to electrostatic stress.

Coaxial Cable

A special type of shielded cable consisting of a central conductor surrounded by an insulator and a second conductor (braid), used to guide Radio Frequency (RF) energy.

Electromagnetic Interference (EMI)

Interference caused when electromagnetic fields induce high voltages in wires; typically shielded by a conductive layer covering $85\%$ or more of the area.

ARINC 429

A complex data bus cable example used for digital electronic systems with a higher frequency.

American Wire Gauge (AWG)

A U.S. Standard set of non-ferrous wire conductor sizes where the larger number represents the smaller wire size.

Thermocouple EMF Output

Small voltage produced between two different metals, normally in the region of $1\,mV$ per $250^{\circ}C$.

Chromel and Alumel

The two different alloy conductors used in Exhaust Gas Temperature (EGT) cables and thermocouples.

EGT Cable Insulator Colors

Specifically white for Chromel and Green or Red for Alumel to prevent installation errors.

Crimping

A solderless method of cable termination where a wire conductor is secured by compression to a terminal or contact, involving a 'cold flow' metal flow process.

AMP PIDG

A type of repair splice meaning Pre-Insulated Diamond Grip.

In-line Splice Spacing Rules

The distance between crimped splices in the same cable run must be no less than $500\,mm$ ($39.7\,inches$).