Residential wiring 21st 1-4 chap
Study online at https://quizlet.com/_gwoera
1. 1. What code sets the standard for electrical installation work in the United
States?: The NEC is the basic standard; local and state codes are to be considered
also.
2. What entity enforces the requirements set by the NEC?: The local electrical
inspection authority or Authority Having Jurisdiction(AHJ)
3. Does the NEC provide minimum or maximum standards?: minimum
4. What do the letters "UL" signify?: When shown on an electrical product or in
a certification mark, it means the product is Listed by Underwriters Laboratories.
It also means that the product met applicable safety standards when it left the
manufacturer's plant.
5. What section of the NEC states that all listed or labeled equipment shall be
installed or used in accordance with any instructions included in the listing
or labeling?: NEC 110.3(B)
6. When the word "shall" appears in an NEC reference, it means that
it(must)(may) be done.: Must
7. What is the purpose of the NEC? What section can this statement be found
in?: The NEC states in 90.2(A) that "The purpose of this Code is the practical safe-
guarding of persons and property from hazards arising from the use of electricity."
8. Does compliance with the NEC always result in an electrical
installation that is adequate, safe, and efficient? Why?: No. The NEC states in
90.2(B) that "This Code contains
provisions that are considered necessary for safety. Compliance and proper mainte-
nance results in an installation that is essentially free from hazard but not necessarily
efficient, convenient, or adequate for good service or future expansion of electrical
use."* Informational Note: Hazards often occur because of overloading of wiring
systems by methods or usage not in conformity with this Code.
This occurs because initial wiring did not provide for increases in the use of electricity.
An initial adequate installation and reasonable provisions for system changes will
provide for future increases in the use of electricity.
9. Name two nationally recognized testing laboratories.: Underwriters Labora-
tories (UL) and Intertek Testing Services
(ETL listing mark). There are other testing laboratories such as
Canadian Standards Association (CSA), Factory Mutual (FM), and others the stu-
dent might refer to that may be acceptable to the authority enforcing the Code.
10. a. Do Underwriters Laboratories and the other recognized testing
laboratories "approve" products?
b. What do these testing laboratories do?: a. No. Approval is up to the Authority
Having Jurisdiction.
See NEC 90.4 and 110.2. b. They test the products for conformance to the applicable
1/7
, Residential wiring 21st 1-4 chap
Study online at https://quizlet.com/_gwoera
product safety standards. When the product passes these tests, the manufacturer of
the product is then permitted to affix a "label" (often referred to as a "listing mark")
that indicates the product complied with the applicable safety standard when it left
their factory.
11. Does the NEC make suggestions about how to wire a house that will
be occupied by handicapped persons?: Informative Annex J includes information
that is intended to assist the users of the Code in properly considering the various
electrical design constraints of other building systems and are part of the 2010
ADA Standards for Accessible Design. The Informative Annex is not enforceable.
The basic NEC rules still apply. Local communities, counties, states, and/or other
govern-mental bodies might have requirements. Check with your local inspection
authority. Ask them if there are any requirements or suggestions that you might need
to follow.
12. A junction box on a piece of European equipment is marked 344 cm3.
Convert this to cubic inches. (Hint: Is there a table that lists
standard box sizes?): 200 0.06102 = 12.204 cubic in.
13. Convert 4500 watts to Btu/hour: 4500/3.4129 = 15.358 Btu/hour
14. You will learn in Chapter 3 that residential lighting loads are
based on 3 volt-amperes per ft.2 (33 volt-amperes per m2). Determine
the minimum lighting load required for an area of 186 m2. Do
calculations for both feet squared and meters squared so you can see
the difference in answers. To convert meters squared to feet squared,
refer to Table 1-8.: Answer: Step 1: Convert square meters to square feet
186 10.764 = 2002 sq. ft Step 2: 2002 3 = 6006 volts-amperes Working in metrics,
the answer is 186 33 = 6138 volt-amperes Note: This is an excellent example of
what happens when converting inch-pound units to metrics, or vice versa. You can
see that the NEC decided to "round-off" 3 volt-amperes per sq. ft to 33 volt-amperes
per square meter. The result is different answers. Not a big difference, but different
nevertheless. Converting a rounded-off inch-pound number to metrics always results
in a fractional metric value. Converting a rounded-off metric number to inch-pound
units always results in a fractional inch-pound value. There is no easy way to
resolve this issue. Just follow the values as found in the NEC. No doubt inch-pound
measurements will be used in this country for quite a while, so use the inch-pound
values until more information becomes available on how to handle conversions in
the NEC. See Tables 1-6, 1-7 and 1-8 in Electrical Wiring Residential. There is also
a comprehensive inch-pound/metric conversion table in Appendix D of Electrical
Wiring Residential. Refer to it often.
15. What federal organization dictates requirements for work-related
safety issues?: OSHA
2/7
Study online at https://quizlet.com/_gwoera
1. 1. What code sets the standard for electrical installation work in the United
States?: The NEC is the basic standard; local and state codes are to be considered
also.
2. What entity enforces the requirements set by the NEC?: The local electrical
inspection authority or Authority Having Jurisdiction(AHJ)
3. Does the NEC provide minimum or maximum standards?: minimum
4. What do the letters "UL" signify?: When shown on an electrical product or in
a certification mark, it means the product is Listed by Underwriters Laboratories.
It also means that the product met applicable safety standards when it left the
manufacturer's plant.
5. What section of the NEC states that all listed or labeled equipment shall be
installed or used in accordance with any instructions included in the listing
or labeling?: NEC 110.3(B)
6. When the word "shall" appears in an NEC reference, it means that
it(must)(may) be done.: Must
7. What is the purpose of the NEC? What section can this statement be found
in?: The NEC states in 90.2(A) that "The purpose of this Code is the practical safe-
guarding of persons and property from hazards arising from the use of electricity."
8. Does compliance with the NEC always result in an electrical
installation that is adequate, safe, and efficient? Why?: No. The NEC states in
90.2(B) that "This Code contains
provisions that are considered necessary for safety. Compliance and proper mainte-
nance results in an installation that is essentially free from hazard but not necessarily
efficient, convenient, or adequate for good service or future expansion of electrical
use."* Informational Note: Hazards often occur because of overloading of wiring
systems by methods or usage not in conformity with this Code.
This occurs because initial wiring did not provide for increases in the use of electricity.
An initial adequate installation and reasonable provisions for system changes will
provide for future increases in the use of electricity.
9. Name two nationally recognized testing laboratories.: Underwriters Labora-
tories (UL) and Intertek Testing Services
(ETL listing mark). There are other testing laboratories such as
Canadian Standards Association (CSA), Factory Mutual (FM), and others the stu-
dent might refer to that may be acceptable to the authority enforcing the Code.
10. a. Do Underwriters Laboratories and the other recognized testing
laboratories "approve" products?
b. What do these testing laboratories do?: a. No. Approval is up to the Authority
Having Jurisdiction.
See NEC 90.4 and 110.2. b. They test the products for conformance to the applicable
1/7
, Residential wiring 21st 1-4 chap
Study online at https://quizlet.com/_gwoera
product safety standards. When the product passes these tests, the manufacturer of
the product is then permitted to affix a "label" (often referred to as a "listing mark")
that indicates the product complied with the applicable safety standard when it left
their factory.
11. Does the NEC make suggestions about how to wire a house that will
be occupied by handicapped persons?: Informative Annex J includes information
that is intended to assist the users of the Code in properly considering the various
electrical design constraints of other building systems and are part of the 2010
ADA Standards for Accessible Design. The Informative Annex is not enforceable.
The basic NEC rules still apply. Local communities, counties, states, and/or other
govern-mental bodies might have requirements. Check with your local inspection
authority. Ask them if there are any requirements or suggestions that you might need
to follow.
12. A junction box on a piece of European equipment is marked 344 cm3.
Convert this to cubic inches. (Hint: Is there a table that lists
standard box sizes?): 200 0.06102 = 12.204 cubic in.
13. Convert 4500 watts to Btu/hour: 4500/3.4129 = 15.358 Btu/hour
14. You will learn in Chapter 3 that residential lighting loads are
based on 3 volt-amperes per ft.2 (33 volt-amperes per m2). Determine
the minimum lighting load required for an area of 186 m2. Do
calculations for both feet squared and meters squared so you can see
the difference in answers. To convert meters squared to feet squared,
refer to Table 1-8.: Answer: Step 1: Convert square meters to square feet
186 10.764 = 2002 sq. ft Step 2: 2002 3 = 6006 volts-amperes Working in metrics,
the answer is 186 33 = 6138 volt-amperes Note: This is an excellent example of
what happens when converting inch-pound units to metrics, or vice versa. You can
see that the NEC decided to "round-off" 3 volt-amperes per sq. ft to 33 volt-amperes
per square meter. The result is different answers. Not a big difference, but different
nevertheless. Converting a rounded-off inch-pound number to metrics always results
in a fractional metric value. Converting a rounded-off metric number to inch-pound
units always results in a fractional inch-pound value. There is no easy way to
resolve this issue. Just follow the values as found in the NEC. No doubt inch-pound
measurements will be used in this country for quite a while, so use the inch-pound
values until more information becomes available on how to handle conversions in
the NEC. See Tables 1-6, 1-7 and 1-8 in Electrical Wiring Residential. There is also
a comprehensive inch-pound/metric conversion table in Appendix D of Electrical
Wiring Residential. Refer to it often.
15. What federal organization dictates requirements for work-related
safety issues?: OSHA
2/7
