Neets Module 4 Assignment 2
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Neets Module 4 Assignment 2
What are the basic requirements for any splice or terminal connection?
The connection must be both mechanically and electrically as strong as the conductor or device with which it is used
What is the preferred method for stripping wire?
By use of a wire-stripping tool
What stripping tool would NOT be used to strip glass braid insulation?
What tool should be used to strip aluminum wire?
Why are the ends of the wire clamped down after a Western Union splice is made?
To prevent damage to the tape insulation.
Why are splices staggered on multiconductor cables?
To prevent the joint from being bulky.
Where is the rattail joint normally used?
When wires are in conduit and a junction box is used.
Which type of splice is used to splice a lighting fixture to a branch circuit?
Which of the splices discussed is NOT a butted splice?
Knotted tap joint.
Why is friction tape used in splicing?
As a protective covering over the rubber tape.
What is a major advantage of the crimped terminal over the soldered terminal?
Requires relatively little operator skill to install.
What are the two types of insulation most commonly used for noninsulated splices and terminal lugs?
Spaghetti or heat-shrinkable tubing.
What is the maximum allowable temperature that should be used on heat-shrinkable tubing?
What is the maximum allowable source pressure that can be used with the compressor air/nitrogen heating tool?
Should aluminum wire be cleaned prior to installing an aluminum terminal lug or splice?
No, it is done automatically by the petroleum abrasive compound that comes in the terminal or splices.
What tools should be used to install large aluminum terminal lugs and splices?
Power-operated crimping tools.
Why should a lockwasher never be used with an aluminum terminal?
It gouges the terminal lug and causes deterioration.
What is the most common method of terminating and splicing wires?
The use of preinsulated splices and terminal lugs.
Besides not having to insulate a noninsulated terminal, what other advantage is gained by using a preinsulated terminal lug?
It has insulation support for extra supporting strength of the wire insulation.
Why are preinsulated terminal lugs and splices color coded?
To identify wire sizes they are to be used on.
Why must items to be soldered be cleaned just prior to the soldering process?
Solder will not adhere to dirty, greasy, or oxidized surfaces.
What does "tinning" mean in relationship to soldering?
The coating of the material to be soldered with a light coat of solder.
Why should wire be stripped 1/32 inch longer than the depth of the solder barrel?
To prevent burning the insulation during the soldering process and to allow the wire to flex easier at a stress point.
How much of the stripped length of a conductor should be tinned?
One-half the stripped length.
What causes a "fractured solder" joint?
Movement of the parts being soldered while the solder is cooling.
Define thermal inertia.
The capacity of the soldering iron to generate and maintain a satisfactory soldering temperature while giving up heat to the joint being soldered.
Why are small-wattage soldering irons not used to solder large conductors?
Although its temperature is as high as the larger irons, it does not have thermal inertia.
State why a well-designed soldering iron is self-regulating.
The resistance of its heating element increases with rising temperature, thus limiting the current flow.
What should be done to a soldering iron tip that is pitted?
File the tip until it is smooth and retin it.
What happens if a soldering gun switch is pressed for periods longer than 30 seconds?
It will overheat and could burn the insulation of the wire being soldered.
What causes the nuts or screws that hold the tips on soldering irons and guns to loosen?
The heating and cooling cycles.
A soldering gun should NOT be used on what components?
Electronic components, such as resistors, capacitors, and transistors.
What is an advantage of using a resistance soldering iron when soldering wire to a connector?
The soldering tips are hot only during the brief period of soldering the connection, thus minimizing the chance of burning the wire insulation or connector inserts.
Why is steel wool NEVER used as an abrasive to clean soldering tools?
The strands can fall into electrical equipment being worked on and cause short circuits.
Why should "antiseize" compound be used on the screw-in tips of the pencil iron?
It enables the tip to be removed easily when another is to be inserted.
If no suitable tip is available for a particular job, how may one be improvised?
Wrap a length of copper wire around one of the regular tips and bend to the proper shape for the purpose.
What two metals are used to from soft solder?
Tin and lead.
Define the metal solvent action that takes place when copper conductors are soldered together.
The solder dissolves a small amount of the copper, which combines with the solder forming a new alloy; therefore, the joint is one common metal.
What is the tin-lead alloy percentage of solder used for electrical connectors, splices, and terminal lugs?
60-percent tin and 40-percent lead (60/40 solder).
What purpose does flux serve in the soldering process?
It cleans the metal by removing the oxide layer and prevents further oxidation during the soldering.
What type of flux must be used in all electrical and electronic soldering?
Noncorrosive, nonconductive rosin fluxes.
Why are solvents used in the soldering process?
To remove contaminants from soldered connections.
What is the purpose of a heat shunt?
To prevent damage to heat-sensitive components.
Besides presenting a neat appearance and supporting each other, what is the other purpose for lacing conductors?
To aid in tracing the conductors when alterations or repairs are required.
Why is flat tape preferred instead of round cord when wire bundles are laced?
Round cord has a tendency to cut into the wire insulation.
What amount of flat tape or round cord is required to single lace a group of conductors?
Two and one-half times the length of the longest conductor in the group.
What is the purpose of a lacing shuttle?
To keep the tape or cord from fouling during the lacing operation.
When should wires be twisted prior to lacing?
When required, such as for the filament leads in electron tube amplifiers.
What precautions should you take when tying bundles containing coaxial cables?
Do not tie too tightly and use the proper type of tape.
How is the single lace started?
With a square knot and at least two marling hitches drawn tightly.
What size wire bundles require double lace?
Bundles that are 1 inch or larger in diameter
How is the double lace started?
With a telephone hitch.
How are laced cable groups bound together?
They are bound together at intervals with telephone hitches.
When are spot ties used?
When wire bundles are supported by cable supports that are more than 12 inches apart.
What is used to install self-clinching cable straps?
Military Standard hand tool.
What is used to tie wire bundles in high-temperature areas?
High-temperature, pressure-sensitive tape.