Electrical Installations (Ch.2)⛔️ Flashcards
Which of the following are classifications of cable types?
Special purpose
No flexing service
Repeated flexing service
What is the purpose of aluminum or steel covering of armored cable?
To give physical protection to the cable sheath during installation.
Which of the following is a purpose for using nonflexing cable?
To use with permanent installations
Flexing service cable designed for use aboard ship is commonly referred to as being portable because
It is principally used as leads to portable electric equipment
Repeated flexing, general use cable is categorized by what means?
The number of conductors in the cable
If you see the symbol HOF on a cable designation, you know the cable is of what type?
Heat and oil resistant, flexible
A cable listed in the Cable Comparison Guide has a 7 at the end of the cable designation. Which of the following is the meaning of 7?
Either 1 or 2, depending on the type of cable
A radio frequency (RF) cable designated as LSTTRSU-10 in the Cable Comparison Guide has what total number of conductors?
20
The designation of a nonflexing service cable is LSDHOF-400. What does (a) the letter D and (b) the number 400 indicate?
Two conductors
Approximate cross-sectional area of a single conductor expressed in thousands of circular mills
A cable has been constructed so that it provides added protection, allowing it to function for a longer period under fire conditions. What term describes this cable?
Circuit integrity
What information is on the thin marker tape present on most cables and cords under the binder or jacket?
All of the above
Before choosing the size of cable to use in a circuit installation, what information is necessary for you to know?
The total connected load current, the demand factor, and the allowance voltage drop
Which of any of the following is the reason for keeping cable runs as short as possible?
To simplify damage control efforts
When determining the total connected load current for a DC power circuit, you should add what number of watts for each installed receptacle?
100
What letters would be used to designate an emergency lighting circuit on a cable supplying 115volts AC to a circuit with a load of 120watts?
EL
You are installing new cables. You should measure the bend radius at what point in the cable?
On the innermost portion of the cable
In what publication will you find the exact method to use when installing cables?
ElMB
What action should you take before you clamp a solder type terminal to a conductor?
Twist the strands tightly, solder them and tin the terminal board
A cable had been newly installed. What type of meter should you use to test the insulation resistance?
Megger
Neutral polarity in a conductor is identified by what color?
White
The marking system for power and lighting cables is shown in what sequence?
Source, voltage, service
A cable marked as (1-129-2)-24-C(2) indicates that the circuit is supplying what maxima voltage?
24V
A circuit marking if (4-168-1)-4P-A(1) indicates that the circuit is supplying (a) what voltages of (b) what type power?
450V
Ships service
If you want cable to present a neat appearance and to be traced easily in equipment, you should take what action?
Lace them together
What is the primary purpose of cable maintenance?
To prevent insulation resistance
What was the driving force for developing the low smoke family of cables?
The Navy needed a new cable that would give off less toxic fumes and smoke during a fire
