ELECTRICAL CONSTRUCTION DRAWINGS Flashcards
(42 cards)
An ____________ shows the layout and design of an electrical installation.
Electrical Construction Drawings
In order to convey the desired design information to the contractor, it is a MUST to obtain complete set of construction drawings and specification of the building electrical system.
electrical construction drawings
Specifications and drawings should be include requirements for:
Raceway and conduit with fittings
Wire and Cable
Electrical boxes, fittings and installation
Electrical Connections
Electrical Wiring Devices
Circuit and Motor Disconnects
Hangers and Supporting Devices
Electrical Identification
Service Entrance and Details
Overcurrent Protection
Switchboards
Grounding
Transformers
Panel boards
Motor Control Centers
Lighting Fixtures
___________ are specifically used at construction drawings to represent LIGHTING and POWER distributions components and equipment.
symbolS
T or F
predominantly, there is no specific symbol set is universally accepted by the industry.
TRUE
SYMBOLS are well - arranged on the drawings in the form of a ______________.
one-line diagram
In symbols, one line represents the ___________ extending between two symbols regardless of the number of ___________. Generally the single line without any additional identification indecates a __________ wire set of ___________ either an ungrounded and grounded conductor or two hot conductors.
conductors, conductors, two - , conductors
A single line with three slashed indicates a ________________ and so on
three-wire set of conductors
It is expressed as a NOMINAL VOLTAGE because it varies slightly. ______________ can carry from about __ to ___% of the nominal voltage under normal conditions.
Supply Voltage, 90, 105
It is the principle voltages available in a building
System Voltage
Medium and High voltage systems carry voltages above _________ V may be used in special cases such as for a large ______.
600, signage
Low voltage systems that carry less than _________ V are typically used in __________.
600, buildings
_______________ is expressed as a nominal voltage because it varies slightly for the reasons mentioned earlier.
System Voltage
CIRCUIT WIRING
It is the initial current-carrying conductor in an AC system. The ___________________ is frequently known as the hot or live conductor because it ________ current to the circuit.
ungrounded ( hot) conductor
CIRCUIT WIRING
____________ is required to complete a single-phase circuit by connecting the hot conductor to it. The _________ is a __________ that serves more than one circuit/
Grounded (Neutral) Conductor, neutral conductor, grounded conductor
CIRCUIT WIRING
It is a third conductor that provides supplementary but imporant GROUNDING PROTECTION. The ___________ is not normally a current-carrying conductor, but is energized only on a temporary, fault between an undergrounded conductor and any metal associated to the electrical equipment.
grounding ( ground) conductor
The most basic system voltage used. It was used in the first electrical services to buildings, however, nearly all have since upgraded.
(120 V AC, 1-2W)
1 - Single phase
2W - 2 wire system
The most common residential electrical service in use today. It is also used on a limited basis in light commercial buildings such as small office buildings, churches and retail shops and stores.
On a _________ V system, a _____ V branch circuit provides electrical energy to convenience outlets, small appliances and light fixtures.
A ______ V bramch circuit serves a large appliances and equipment such as electric resistance baseboard heaters, water heaters, and air conditioning equipment
120/240 V AC, 1-3W, 120, 240
A ________ runs continuously through all branch circuits and serves as a safety circuit incase of a short circuit.
grounding conductor
It is an older electrical service found in small commercial buildings and high rise buildings where three-phase motors, above about ___ horsepower, and equipment such as large air conditioners are used. It is not used very often in industry because a _________ V system is more economical for large C motor loads.
(208Y/120V AC, 3-4W), 0.5, 480
It is a common electrical service in most modern medium to large commercial buildings. The _______ V, 3 phase power is used to power specially designed heavy machinery. , High voltage _______ V fluorescent lighting and other single-phase devices have also been developed specifically for use with these system.
Large retail shopping malls, grocery supermarkets, and office buildings may use this system for its _______ V fluorescent lighting capabilities where fixtures are not located closer than ___ ft away from windows, platforms, and fire escapes.
480 Y/277 V AC, 3-4W, 480, 277, 277, 3
It is a less common electrical service in large commercial buildings and industrial buildings that is used to power specially designed machinery. This system is designed like the 480Y/277V AC, 3-4W except that ________ V, and _________ V are available in the circuot or feeder configurations
600Y/346 V AC, 3-4W
It is another failry common electrical service found in commercial and industrial buildings where 3 ohase mtots , above 0.5 hp and equipment such as large air conditioners are used. On this 3-4W delta connected system, the midpoint of one phase winding is _______ to provide ________ V between phase X and ground and pahse Z and ground only.
There are _______ V between the windings of each pahse, that is between Phases X and Y, Phases X and Z or phases Y and Z. Between Phase Y and ground, there is ___________ V available. ___________ is known as the high leg or wild leg because it has higher voltage to ground than the other legs.
240/120V AC, 3-4W, neutral, 120,
240, 208, Phase Y
It is the target voltage entering the service panel. ___________ will vary slightly for different buildings because of variations of voltage available at the __________ and __________ in the service conductors. The standard for the system voltage is actually ___________.
System Voltage, System Voltage, transformer, voltage drop, 120/240
