7 - Electrical Wiring Flashcards
What is the mechanism for releasing a pin in a front release connector?
The pin is released from the front and extracted from the rear.
What is the minimum bend radius for a wire clamped vertically at one end and horizontally at the other?
Three times the diameter of the wire.
What can glycol deicer fluid in contact with a silver cable cause?
A fire.
How is the pin released in a rear release connector?
The pin is released from the rear and extracted from the rear.
What is the maximum operating temperature for a nickel plated copper or aluminium connector?
260°C.
On what gauge of pin is a yellow plastic insert/extract tool used?
12–10.
How can the insulation grip on a PIDG crimp tool be adjusted?
By adjusting the pins.
On what gauge of pin is a red plastic insert/extract tool used?
22–18.
Which type of cable should be used where temperatures exceed 200°C?
Nickel plated copper or aluminium.
How long should a fireproof cable last in a fire?
15 minutes.
On what gauge of pin is a blue plastic insert/extract tool used?
16–14.
What is the minimum insulation resistance for wiring in undercarriage wheel‑wells?
2 megohms.
What causes knuckling on older type electrical cables?
Excessive pull through forces.
What test should be performed to find a high resistance or open circuit?
A continuity check.
What is the maximum bonding resistance on an aircraft primary structure?
0.05 ohms.
How should the bare ends of a cable be prepared before crimping?
They should be twisted lightly in the direction of the lay.
What does the number of dots impressed on the insulation of pre‑insulated connectors indicate?
That the correct tool was used to effect the connection.
How can the pressure of the insulation crimp jaws on a PIDG crimping tool be altered?
By changing the position of the pins.
What does HRC mean in reference to fuses?
High rupture capacity.
What color is the live wire when wiring an electrical component to a plug?
Brown.
Why is a hole placed at the lowest point of electrical cable conduit?
To allow for drainage of moisture.
What is the minimum distance between electrical cable splices?
500 mm.
For how long is a fire‑resistant cable proof tested by exposure to a standard fire?
5 minutes.
When fitting coaxial cable connectors, what is essential to ensure?
That no seals are damaged.
When inserting pins into a front release connector, in which direction should the inserting tool’s gap face?
The outside of the connector.
When is a crimp considered formed on a hydraulic crimping tool?
When the bypass valve opens and the ram returns to neutral.
What type of binding tape is used for cables in temperatures above 260°C?
Teflon.
What is the minimum bend radius for a loom adequately supported at a terminal block?
Three times the diameter.
How are front release pins removed?
The tool is inserted from the front and the pin is removed from the rear.
If a coaxial cable clamp is over‑tightened and compresses the dielectric, how does the capacitance change?
It increases.
What is the minimum bend radius for a single coaxial cable?
Six times the diameter.
What is wet arc tracking?
It is a fault caused by hot stamp printing.
When using a heat shrink gun, to what temperature should it be set relative to the heat shrink temperature?
100° above the heat shrink temperature.
In an electrical cable designation 1EF6B22NMS, what does the letter E represent?
Circuit function.
How is cable impedance on a coaxial cable affected by its length?
It is not affected by length.
What constitutes a secondary earth?
A secondary earth is typically 18 AWG.
Under ATA 100, what does the symbol E′ on a wire indicate?
It indicates the system ID code.
To prevent wet arc tracking, what should be controlled?
Hot stamp printing must be controlled.
When splicing a cable with a soldered joint, when is the operation considered complete?
When the solder and insulation have formed.
In manufacturing an electrical connector, what is done with the unused holes?
They are filled with connectors and blanked.
In which application is coaxial cable preferred to airframe cable?
When the diameter of the cable is not important.
How are forward release electrical connectors removed?
They are removed by pulling the wire backwards.
How should wires be prepared when crimping?
They should be lightly twisted.
Why are copper wires used in electrical systems?
Because they have a low resistance to current.
When crimping wires, how should the wire be positioned relative to the crimp?
It should extend 0.8 mm beyond the crimp.
In the cable designation 1EF6B22 NMSV, what does the letter B represent?
It represents the segment letter.
What gauge of pin is a white/blue insertion‑extraction tool used on?
16.
How does the insulation resistance of an electric motor compare to its supply leads?
It is smaller.
According to ATA 100, what does the symbol code “X” on a wiring number denote?
AC power.
When securing wire after it leaves an LRU, what is the minimum bend radius of the cable bundle?
Eight times the outside diameter of the cable or bundle.
When terminating an aluminium cable, what preparation should be carried out before crimping?
Apply a mixture of 50% petroleum jelly and zinc oxide.
Where should an in‑line splice be positioned?
On the outer surface of the loom for easy inspection.
After crimping, what is the maximum conductor protrusion allowed from the terminal?
1/32 inch.
When using a hand‑operated wire stripper, if the total stripping length exceeds a certain value, how many operations should be performed?
Two or more operations should be performed if the stripping length exceeds 0.75 inch.
Through which location should a cable loom be protected by conduit?
Through the wheelwell door.
What should the conduit size be relative to the maximum diameter of the electrical wires?
The conduit should be 25% larger than the maximum diameter of the wires.
What gauge of contact is a blue metal extract tool used on?
16.
What is the likely consequence of a silver‑coated conductor with damaged coating in a moist, unpressurized area?
It will likely cause Red Plague.
