Wiring, Connectors, and Terminations
Core concepts
A wire is a conductor, insulation and often a shield. American Wire Gauge numbers run inversely: a larger AWG number means a smaller conductor with less current capacity. Select wire for current, voltage drop, temperature, altitude and bundle derating. Voltage drop = current x loop resistance; keep it within the equipment limit.
Connectors may be circular, rectangular or D-subminiature, with pins and sockets, keying and coupling threads. Crimped contacts need the correct tool and a pull check; soldering needs clean surfaces and no acid flux. Terminal lugs, splices and shield terminations must be mechanically sound and insulated. Shields are normally grounded at one end to avoid ground loops, following the installation instructions.
Route wiring with adequate support, protection from chafing and heat, and separation between power and sensitive signal wires. Observe minimum bend radius, commonly about ten times the cable diameter, keep coax bends gentle, and identify circuits clearly.
Traps
Expect questions on AWG direction, crimp versus solder, shield grounding at one versus both ends, and using the wrong flux or tool. Bigger number meaning bigger wire is a classic wrong answer.
Worked example
A 10 A load flows through a 0.05 ohm run. Voltage drop = 10 x 0.05 = 0.5 V. On a 28 V bus that is about 1.8 percent - acceptable for most loads, but repeat the check after any connector or splice is added.