study guide Flashcards
A _____ is a unit of electrical system other than a conductor that carries or controls electric energy as its principle
device
Art. 100
a ____ is a part of the wiring system that is intended primarily to perform a mechanical function
fitting
a device box is also known in the field as a?
switch box
A box with 4 internal cable clamps is how many additional conductors to the fill
1
external cable clamps add how much to fill allowance?
0
a 4 square box with two receptacles installed adds how many to the fill allowance?
4
straight pulls =____?
angled pulls=______?
x8
x6
formula for voltage drop in a single phase system?
2xKxLxI divided by area
formula for voltage drop in a 3 pahse system
1.73xKxLxI divided by area
A _____ box is a box installed in a run of CONDUIT for the purpose of making splices
pull box
A _____ box is a box installed in a run for the purpose of making splices
junction box
A ______ is a separate portion of a conduit or tubing?
conduit body
what statement respresents the purpose of the NEC?
the practical safeguarding of persons and property from hazards arising from the use of electricity
when the NEC is followed during an electrical installation the installation will be?
essentially free from hazards
where do you find nominal voltages in the code book?
220.5 (A)
where conductor material is not specified, the sizes given in the NEC shall apply to?
copper
throughout the NEC conductor sizes are expressed in ____ and ______
AWG and Circular mils
definitions for terms found in a single article will have the article number in parenthesis the definition
true or false
true
definitions for terms found in multiple articles will have an article number in parenthesis following the definitions
true or false
false
the NEC ______ intends to define terms which have general usage elsewhere
does or does not
does not
Ampacity calculations with respect to the conductors should focus on the maximum operating temp of which part of the conductor?
insulation
Do you count the neutral in a non linear load?
yes or no
yes
Do you count the neutral if a phase is missing?
yes or no
yes
A load being used for 3 or more hours is a ?
continuous load
where different temp limits of individual components are applied to a single circuit the principle of _______ is often used to determine the temp rating of the entire circuit
weakest link
both alu and copper are available in compact?
true or false
True
