CH 16 Test Flashcards
The American Wire Gauge lists the largest wire as ______
0000 (4/0)
A(n) _____ of enclosure can only be used where there were no problems of moisture, dust, or explosive fumes.
General type
Circular mil sizing runs from 250 MCM to _____ MCM.
750
A(n) _____ disconnect enclosure could be used in areas of moisture but not where dust or explosive fumes exist.
Rain-tight
Fusible load center, or _____, are electric panels that supply the circuits in a structure with power and protect those circuits with fuses.
Fuse box
A(n) _____ enclosure can be used in any location, but it is much more expensive than other enclosures and therefore, is not used unless there is a viable reason.
Explosion-proof
Standard wire size is defined in the United States by the _____
American wire gauge (AWG)
What is the purpose of a breaker?
To detect an overload above their rating in a circuit and open the circuit automatically
What is the function of a main breaker?
Main switch in the panel which provides overload protection for the entire panel
What are four factors to consider when selecting circuit conductors?
Voltage drop, insulation type, enclosure, and amperage
What is the purpose of an electrical distribution center?
distribute the electrical supply to several places in a large structure
Why is a fusible design distribution center more popular than the circuit-breaker design?
Because of its moderate cost
Aluminum is a good conductor of electricity; however, it has a tendency to corrode. True or False.
True
The allowable voltage drop of most manufacturers is 15% below the nameplate rating. True or False.
False
10%
All heating, cooling, and refrigeration equipment should have some means for disconnecting the power supply at the equipment. True or False.
True
The maximum recommended voltage drop for a branch circuit is eight percent. True or False.
False
3%
The type of insulation surrounding the conductor usually determines its application and the amperage for which it can be used.
True
Copper wire bends easily, has good mechanical strength, resists corrosion, and can be easily joined. True or False.
True
Voltage drop in a conductor is of least importance when sizing wire. True or False.
False
To calculate the voltage drop in a conductor, you must know the number of feet of wire that is used. True or False.
True
