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37 Cards in this Set
- Front
- Back
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The preferred method of removing insulation is with a... |
Wire stripping tool |
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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 |
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What stripping tool would not be used to strip glass braid insulation? |
Hot blade stripper |
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What tool should be used to strip aluminum wire? |
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Why are the ends of the wire clamped down after a Western Union splice is made? |
To prevent damage to the tape insulation |
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Why are splice staggered on multiconductor cables |
To prevent the joint from being bulky |
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Where is the rattail joint normally used? |
When wires are in conduit and a junction box is used |
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Which type of splice is used to splice a lightning fixture to a branch circuit |
Fixture joint |
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Why is friction tape used in splicing? |
As a protective covering over the rubber tape |
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What is a major advantage of the crimped terminal over the soldered terminal? |
Requires relatively little operator skill to install |
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What are the 2 types of insulation most commonly used for non insulated splices and terminal lugs? |
Spaghetti or heat shrinkable tubing |
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What is the maximum allowable temperature that should be used on heat shrinkable tubing? |
300 °F |
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What is the maximum allowable source pressure that can be used with the compressor air/nitrogen heating tool? |
200 psig |
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What tools should be used to install large aluminum terminal lugs and splices |
Power-operated crimping tools |
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Why should a lock washer never be used with an aluminum terminal? |
It gouges the terminal lug and causes deterioration |
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What is the most common method of terminating and splicing wires? |
The use of preinsulated splices and terminal lugs |
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Besides not having to insulate a non insulated terminal, what other advantage is gained by using a preinsulated terminal lug? |
it has insulation support for extra supporting strength of the wire insulation |
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Why are preinsulated terminal lugs and splices color coded? |
To identify wire sizes they are to be used on |
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Why must items to be soldered be cleaned just prior to the soldering process? |
Solder will not adhere to dirty, greasy, or oxidized surfaces |
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What does "tinning" mean in relation to soldering? |
The coating of the material to be soldered with a light coat of solder |
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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 |
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How much of the stripped length of a conductor should be tinned? |
One-half the strip length |
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What causes a "fractured solder" joint? |
Movement of the parts being soldered while the solder is cooling |
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Describe 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 |
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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 |
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State why well-designed soldering iron is self-regulating |
The resistance of its heating element increases with rising temperature, thus limiting the current flow |
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What should be done to a soldering iron tip that is pitted? |
File the tip until it is smooth and retin it |
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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 |
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What causes the nuts or screws that hold the tips on soldering irons and guns to loosen? |
The heating and cooling cycles |
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A soldering gun should NOT be used on what components? |
Electronic components, such as resistors, capacitors, and transistors |
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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 |
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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 |
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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 |
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If no suitable tip is available for a particular job, how may one be improvised |
Wrap a length of copper wire around of the regular tips and bend to the proper shape for the purpose |
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What 2 metals are used to form soft solder? |
tin and lead |
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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 |
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What is the tin-lead alloy percentage of solder used for electrical conductors, splices, and terminal lugs? |
60% tin and 40% lead |
