Electrical Flashcards
Service cable over public streets, roads, alleys, and parking areas with truck traffic should be what height?
18 feet
If one of the the hot wires on the service is tide back, the report should state that the service is only what?
120 volt
Service cable’s height over residential properties, yards, driveways, and any other parking areas should be?
12 feet
A mast in excess of 3 feet above a roof surface may require?
Support
A service cable going over a roof of less than 4:12 with no pedestrian traffic should be at what height?
8 feet, maintained for a distance of at least 3 feet in all directions from the edge of the roof
Square meter bases: Typically found on homes from the 1950s to 1970s are rated for how many amps?
100-125 amps
A service cable of 300v or less crossing over a roof surfaces area that is guarded or isolated should be what height?
3 feet
A service cable’s vertical clearance to a through-the-roof raceway or approved support above the overhanging portion of the roof that is less than 4 feet measured horizontally should be what?
18 inches
Service cable’s height over all walking areas, sidewalks, decks, roof surfaces and patios used by pedestrians only, measured from final grade or other accessible surfaces?
10 feet at the electrical service entrance, at the lowest point of the drip loop
For a 3-phase power supply, the inspector needs to defer to?
A Qualified industrial or commercial electrical contractor.
Service drop’s height over commercial parking areas?
18 feet
Rigid conduit should be attached to the structure every ______ from both sides of the meter base and 5 to 6 feet along its length.
12 inches
SE cable not in conduit should be attached to the building every _______ along its length and within a foot of its top and any meter can.
30 inches
Type UF cable must be buried to a depth of ?
18 to 24 inches
Round meter bases were common in the 1920s and 1950s are rated for how many amps?
60 amps
Service drop’s height over roofs surfaces having a slope of 4:12 or greater
3 feet
Rectangular meter bases are the current minimum on single-family homes and are rated?
200 amps and typically bear the marking “200CL.”
SEC’s vertical clearance from sides of doors, porches, decks, stairs, ladders, fire escapes and balconies, and from the sides and bottom of windows that open
3 feet from the bottom, sides and front
Which branch circuit conductors should be sized one to two sizes larger than copper?
Aluminum
If a service entrance has a 200-amp supply, the minimum cable size should be what?
2/0 copper or 4/0 aluminum
The maximum breaker rating ______ exceed the allowable ampacity of the conductor.
must not
A service drop should be at least _______ away from any nearby trees.
5 to 6 feet
An electrical service mast that extends _________ above the roof surface needs to be supported separately.
5 feet or more
Rigid service masts should be secured to the structure every ________.
5 to 6 feet
The typical supply for a Square brand electric meter is what?
100 amps
The minimum conductor size for a 100-amp service is what?
4-awg copper or 2-awg aluminum
Most areas require how many means of separate grounding?
2
The minimum size for a listed, stainless steel, driven grounding rod is what?
5/8-inch diameter and 8 feet long.
Which supply piping cannot be used as a grounding means?
Gas
Which panel enclosures need to be bonded to ground?
All of them
The grounded and grounding conductors can share a common bus in which panel?
The service panel.
You can bond a remote distribution panel by connecting the enclosure to what?
The grounding bus
A split-bus electrical panel uses a double-pole breaker to _____ the 120-volt circuits.
Isolate
The minimum service required for a new single family home is what?
100 amps
What size wire would be used for 200 amps?
4/0 Aluminum/Copper-Clad or 2/0 Copper
Most homes constructed between 1930 and 1950 originally had what size service?
60-amp
Are wire splices an electrical panel defect?
No
What size wire would be used for 150 amps?
2/0 Aluminum/Copper-Clad or #1 Copper
The available service amperage is based on what?
The lowest rated component.
What size wire would be used for 100 amps?
2 Aluminum/Copper-Clad or #4 Copper
Where is a service panel not allowed?
Inside a bathroom, over stairs, or inside a clothes closet.
What size wire would be used for 125 amps?
1/0 Aluminum/Copper-Clad or #2 Copper
Electrical service panels should be in a clear space measuring what?
30” wide by 78” high by 36” deep.
What type of screws are not allowed for grounding connections?
Sheet metal screws
Correct breaker types should be used for each panel-board, according to what?
The manufacturer’s label.
No circuit should be identified in a way that may be subject to change with?
Occupancy.
All 15- and 20-amp 120-volt circuits for dining rooms, living rooms, bedrooms, sun rooms, closets, hallways, or similar areas must be protected by?
AFCI
All unused holes in the panel should be?
Closed.
To isolate grounds and neutrals, subpanels should be supplied with a conductor with how many wires?
4
If they are the same size, and the maximum number of conductors does not exceed the recommendations of the panel manufacturer, multiple what may be installed under the same terminal?
Multiple grounding conductors or “grounding wires”.
If over-current protection is provided for the feeder conductors, the subpanel does not require a what?
A main breaker.
In a subpanel, what must not be installed to the neutral bar?
A bonding jumper
How many amps would a typical subpanel supplied by a feeder using #2 AL SEC cable or #4 CU SEC cable be?
100-amps
Unless identified by the manufacture, how many neutral wires should be on a single terminal?
One.
