Electrical

in fuse panels look for

. What is the main fuse rating? 2. Are there double taps? 3. Does the rating of the fuse match the conductors? 4. Are the fuses updated to S-type? 5. Is there any sign of conductors overheating?

circular mill is the area of a circle with a diameter of ______ of an inch? In North America conductors larger than 4/0 AWG are typically identified by _________?

.001; kcmil

30 Amp Service requires a _____ wire diameter and ___ in copper and ___ in aluminum.

.102; 10AWG; 8AWG

60 Amp Service requires a _____ wire diameter and ___ in copper and ___ in aluminum.

.162; 6awg; 4awg

100 Amp Service requires a _____ wire diameter and ___ in copper and ___ in aluminum.

.204; 4awg; 2 awg

150 Amp Service requires a _____ wire diameter and ___ in copper and ___ in aluminum.

.289; 1awg; 2/0awg

200 Amp Service requires a _____ wire diameter and ___ in copper and ___ in aluminum.

.365; 2/0awg; 4/0 awg

400 Amp Service requires a _____ wire diameter and ___ in copper and ___ in aluminum.

.632; 400kcmil; 600kcmil

two methods of providing ground back to the service panel are?

1. 4 conductor feeds with ---- two hot or ungrounded connectors---one neutral or ungrounded connector---- one grounding conductor. 2. 3 conductor feeders with--------two hot to ungrounded conductors---- one neutral or grounded conductor ---- equipment grounding through conduit/tubing.

The inspector shall report as in need of correction:

1. deficiencies in the integrity of the service-entrance conductors' insulation, drip loop, and vertical clearances from grade and roofs; 2. any unused circuit-breaker panel opening that was not filled; 3. the presence of solid conductor aluminum branch-circuit wiring, if readily visible; 4. any tested receptacle in which power was not present, polarity was incorrect, the cover was not in place, the GFCI devices were not properly installed or did not operate properly, evidence of arcing or excessive heat, and where the receptacle was not grounded or was not secured to the wall; and 5. the absence of smoke and/or carbon monoxide detectors.

The inspector shall inspect:?

1. the service drop; 2. the overhead service conductors and attachment point; 3. the service head, gooseneck and drip loops; the service mast, service conduit and raceway; 4. the electric meter and base; 5. service-entrance conductors; 6. the main service disconnect; 7. panelboards and over-current protection devices (circuit breakers and fuses); 8. service grounding and bonding; 9. a representative number of switches, lighting fixtures and receptacles, including receptacles observed and deemed to be arc-fault circuit interrupter (AFCI)-protected using the AFCI test button, where possible; 10. all ground-fault circuit interrupter receptacles and circuit breakers observed and deemed to be GFCIs using a GFCI tester, where possible; and 11. for the presence of smoke and carbon-monoxide detectors.

Overhead wires from the street should be higher than ____ feet above the ground, not in contact with tree branches or other obstacles, and not reachable from nearby windows or other accessible areas

10

steel framing grounding must have at least ___ feet into the ground

10

If a flat roof is used as a garden, the minimum clearance required for the service drop is _______ feet.

10 feet

walking areas, sidewalks, decks, roof surfaces

10 feet

For a 10-gauge copper wire, the maximum overcurrent protection rating is _____ amps.

100

For houses serving one family, the ampacity of the ungrounded service conductors shall be a minimum of ______ amperes, 3 wire

100

clearance over residential properties, yards, driveways, etc.

12 feet

the most common types of distribution cable, NM-B can be written in three ways?

14/2 (white) = 14AWG; 12/2 (yellow) = 12AWG; 10/3 =10AWG

vertical clearance of overhead wires for streets?

18 feet

Breaker panels started appearing in homes in the mid-1950s in small numbers, and were universal in most areas by the late

1960s.

on a typical 240/120-volt service drop, we will have _____ ungrounded conductors and a single grounded conductor.

2

If a service entrance has a 200-amp supply, the minimum cable size should be ______________.

2/0 copper 4/0 aluminum

ufer ground requirement is at least ____ feet of #4 _________, or #____ awg copper wire embedded in two inches of concrete.

20; rebar, #4 copper wire.

vertical clearance overhead for swimming pools?

22.5

14 gauge wire is rated for ____ amps?

25

ground ring minimum is __ awg buried __ inches.

2awg; 30 inches

A mast in excess of _____ feet above a roof surface may require support

3

A service entrance cable should be secured to the structure every ___ inches?

30

For a 12-gauge copper wire, the maximum overcurrent protection rating is _____ amps.

30

Panels should be on a free wall space not less than ___ inches wide, have a clear ___ inches of space in front of them, and have 6 feet and 6 inches of head room. The panel, though, is not required to be centered in this space.

30; 36

100-amp to 400-amp services are based on 3-wire, 120/240-volt systems, and _____________ of the NEC.

310.15 (B)(6)

The minimum size for a copper grounding electrode rod _______.

5/8 inch - 8 feet long

Rods made of stainless steel and copper, or zinc-coated steel, shall be at least ______________ in diameter.

5/8-inch

It is required that the entire electrical supply to the home be able to be shut off with ___ or fewer moves of the hand

6

no more than ___ breakers can be used as the main disconnect?

6 - newer houses typically have 1

all other installations the ungrounded conductors should have an ampacity of at least ___ amps?

60

Most residential construction requires two separate grounding electrodes in any combination of the following (which need to be at least _____ feet apart):

6; driven rods most common

The combination-type AFCIs are designed to activate when there is a parallel arc that reaches a peak of

75 amps

Rod and pipe electrodes must be at least __ feet in length to be considered a grounding electrode.

8

How can you bond a remote distribution panel?

???

___________ _______ is a distribution or load center that contains the main disconnecting means. This is the ONLY panel where the neutral and grounds should be joined (bonded) together.

A service panel

current is measured in?

Amperes

electrical size analogy

Amps = E / R Current = flow rate = Amps = I Voltage = pressure = Volts = E Resistance = pipe size = Ohms = R

Inspecting Service Panels

Are the neutral and ground connected (bonded)? Is the panel enclosure connected (bonded) to ground? Does each neutral conductor terminate at a separate lug on its bus?

AWG American gauge wire is also known as? and the 0's in larger sizes are referred to _________?

Brown and Sharpe; aughts

Bonded

Connected to establish electrical continuity and conductivity.

T/F: Electrical service masts can support telephone cables.

False

the difference between grounding and bonding is:

Grounding is a direct connection to the earth--The purpose of bonding is to ensure the electrical continuity

Inspecting Distribution Panels

How is the service grounded back to the service panel? Are the neutrals and grounds separated? Is the neutral bus isolated from the panel enclosure? Is the panel enclosure connected (bonded) to the grounding bus? Does each neutral conductor terminate at a separate lug on its bus?

the top of the electrical mast is called ?

Mast head or gooseneck

are the current minimum on single-family homes. These are rated for 200 amps and typically bear the marking "200CL."

Rectangular meter bases:

Common from the 1920s up to the 1950s, they were rated for only 60 amps and are still often seen on older properties.

Round meter bases:

if the electrical service is not in a metal mast a _______________ can be used?

Service Entrance Cable (SEC)

Typically found on homes from the 1950s to 1970s, these are still used in some smaller housing units, such as apartments, and were only rated for 100-125 amps.

Square meter bases:

WATTS measure?

The power

Common Ohms Laws are:

Watts equals Volts times Amps, or W = E x I. Another would be Amps = Watts divided by Volts, or I = W / E.

The service equipment is the necessary equipment, usually consisting of

a circuit breaker(s) or switch(es) and fuse(s) and their accessories,

____________ need to be bonded to ground.

all panel enclosures

every panel should be labeled explaining what it can be used for i.e. ?

amp load, how many circuits

The ground wire (the grounding electrode conductor) needs to be fastened (referred to as the attachment) with the correct approved clamp called ?

an acorn clamp. Not on the screw side.

drip loops must be _________ the weather head?

below

____________ is the grounding of all outlets and appliances of the home to the grounding system.

bonding

If the ground bus is isolated from the enclosure (for example, by an insulated plastic bushing), a ____________ _________ needs to be installed between the bus and the metal enclosure.

bonding jumper

According InterNACHI's Standards of Practice, inspectors are required to: test all ground-fault circuit interrupter receptacles and

circuit breakers observed and deemed to be GFCIs using a GFCI tester, where possible.

A combination type arc-fault circuit interrupter should be installed

circuits that supply 120-volt, single-phase, 15- and 20-ampere outlets installed in family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreations rooms, closets, hallways,

Ufer ground is also known as?

concrete encased electrode

Voltage is equal to ________.

current (I) multiplied by resistance (R)

Remember that the panel with the main disconnect is the service panel, and panels downstream (or on the load side) of the service panel are _____________ panels.

distribution /subs

In these panels, the neutral and grounds should be separate, and the neutral bus should be isolated from the panel enclosure.

distribution panels

The service point is the point of connection (orange arrows) between the ?

facilities of the service utility and the premises' wiring.

Currents of 50 to 100 milliamperes (1 mA = 1/1,000 of 1 amp) can be ?

fatal

Conductors between the main service disconnect to the distribution panels are called

feeders

Where the service entrance cable is not rated for direct burial, it needs to be in a ____ ______, and must be buried at a minimum depth of __ inches under landscape, and __ inches under hardscape, such as driveways.

full conduit, 18; 24

AWG is colloquially referred to as _______ and the zeros in large wire sizes are referred to as ________?

gauge; aught

The ______________ ___________ _______________ is the conductor that connects to the grounding electrode, and its size is dictated by the size and, therefore, the amperage of the service conductors

grounding electrode conductor GEC

American wire gauge (AWG)

is a standardized wire gauge system used since 1857 predominantly in North America for the diameters of round, solid, nonferrous, electrically conducting wire

3 types of disconnects

knife switch (oldest); fuse blocks (main and range panel); breakers (most common)

Grounding is a direct connection to the earth to aid in removing damaging transient over-voltages due to

lighting

Many homes from the 1930s onward used

main and range panels

Properly bonding all ____________ within an electrical system helps ensure a low-impedance fault current path

metal parts

The maximum breaker rating must _____ the allowable ampacity of the conductor

not exceed

________ are the units used to measure resistance.

ohms

bonding is to ensure the electrical continuity of the fault current path, to provide the capacity and ability to conduct safely any fault current likely to be imposed, and to aid in the operation of the

over protection of a device

Most areas require two means of____________ grounding

separate

An electrical service mast that extends 5 feet or more above the roof surface needs to be supported ____________.

separately

Neutrals and grounds should be bonded together ONLY in the _____________ panel, and not in any downstream distribution panels

service

An underground service entrance is called a __________.

service lateral

There are only two types of panels

service panels and distribution panels

On a fuse panel the power disconnect may look like two cartridge fuses also known as?

shotgun shells (60-100amp)

Where the grounds and neutrals (grounded conductors) share a bus, a bond should or should not bridge between that bus and the enclosure?

should

ground plates as grounding made of ferrous metal like iron or _______ should have a thickness of at least ___ inches thick and ___ square feet.

steel; 0.6, 2 square feet

The clearance for open overhead service conductors from the front, bottom, and sides of windows that ______ is 3 feet.

that open ?????

The inspector shall describe:

the main service disconnect's amperage rating, if labeled; and the type of wiring observed.

VOLTS measure?

the pressure under which electricity moves

AMPS measure?

the volume of current

gas piping should not be used as a grounding rod?

true

_____ connections are now required by most jurisdictions to ensure a low-impedance ground (one with little resistance).

two

the rating (or fuse or breaker size) of the disconnect relates to the total amperage available ___

within the home.

is a jumper at the meter required for grounding?

yes