North Dakota Administrative Code
Title 24.1 - State Electrical Board
Article 24.1-06 - ELECTRICAL WIRING STANDARDS
Chapter 24.1-06-50
Appendix A

Current through Supplement No. 394, October, 2024

Short Cut At 75° C

Voltage Drop Formulas 167° F

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or

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L = length in feet, one way

I = load in amps

E = Volts

C.M.A. = circular-mil area

K-factor = 25.8 multiplying factor for copper, 42.4 multiplying factor for aluminum at 75° C.

Percent drop = permissible voltage drop times voltage of circuit as follows:

3% of 208 = 208 x .03 = 6.24 volts

3% of 120 = 120 x .03 = 3.6 volts

3% of 240 = 240 x .03 = 7.2 volts

5% of 240 = 240 x .05 = 12.0 volts

Example:

240 volts, 1,000 ft. distance, 10 ampere load, 5% drop

25.8 x 1,000 = 25,800 x 10 = 258,000

258,000 divided by 26,250 (C.M.A. of No. 6) = 9.8 volts (less than 5%)

258,000 divided by 16,510 (C.M.A. of No. 8) = 15.6 volts (more than 5%)

120 volts, 8 ampere load, 100 ft. distance, 3% drop

25.8 x 100 = 2,580 x 8 = 20,640

20,640 divided by 6,530 (C.M.A. of No. 12) = 3.16 volts (less than 3%)

20,640 divided by 4,107 (C.M.A. of No. 14) = 5.0 volts (more than 3%)

or

25.8 x 8 amps x 100 ft. = 20,640

20,640 divided by 3.6 (volts representing 3%) = 5,733 C.M.A. (No. 12)

For 3-phase circuits, use formula, then multiply the results by .86.

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Means of Egress Condensed Guide

1. Marking of means of egress. All required exits and access to exits shall be marked by readily visible signs. For externally illuminated signs, letters may not be less than six inches [150 millimeters] high. Internally illuminated signs must be listed per ANSI/UL 924 which assures proper letter size. Chevron-shaped arrows are required to indicate direction to exits. Every sign must be suitably illuminated. For externally illuminated signs see subsection 7.10.6, Life Safety Code®, NFPA 101, 2015 edition and for internally illuminated signs see subsection 7.10.7.

2. Illumination of means of egress. Illumination of means of egress must provide continuous, dependable, illumination of not less than one foot-candle at floor level for all areas such as corridors, stairways, and exit doorways, providing a lighted path of travel to the outside of the building and public way during all times that the means of egress is available for use. For new stairs, the required minimum illumination level is ten foot-candle during conditions of stair use. Illumination must be from a source of reasonable assured reliability and may be supplied from normal lighting circuits or special circuits with switching controlled by authorized personnel. Illumination required for exit marking also must serve for illumination of means of egress and be so arranged that failure of a single unit, such as burning out of a single bulb will not leave any area in darkness.

3. Emergency lighting. Emergency lighting systems must be so arranged to provide the required illumination automatically in event of any interruption or failure of the normal power supply. An acceptable alternate source of power may be an electric generator or approved battery. In occupancies where emergency lighting is required, the circuits supplying exit marking and illumination of means of egress must be supplied by the emergency system. Other areas of the facilities only requiring exit marking and illumination of means of egress may be supplied by the normal source.

4. Classification of occupancy based on chapter 6, Life Safety Code®, NFPA 101, 2015 edition.

Note: Check with local building officials to determine occupancy and occupant load.

Assembly. Assembly occupancies include all buildings or portions of buildings used for gathering together fifty or more persons for such purposes as deliberation, worship, entertainment, eating, drinking, amusement, or awaiting transportation. Assembly occupancies also include special amusement buildings regardless of occupant load.

Assembly occupancies might include the following:

Occupancy of any room or space for assembly purposes by fewer than fifty persons in a building or other occupancy and incidental to such other occupancy must be classified as part of the other occupancy and is subject to the provisions applicable thereto.

Educational. Educational occupancies include all buildings or portions of buildings used for educational purposes through the twelfth grade by six or more persons for four or more hours per day or more than twelve hours per week.

Educational occupancies include the following:

Other occupancies associated with educational institutions shall be in accordance with the appropriate part of Life Safety Code®, NFPA 101, 2015 edition.

In cases when instruction is incidental to some other occupancy, the section of Life Safety Code®, NFPA 101, 2015 edition, governing such other occupancy applies. For example:

College and university classrooms under fifty persons - business occupancy

College and university classrooms fifty persons and over - assembly

Instructional building - business occupancy

Laboratories, instructional - business occupancy

Laboratories, noninstructional - industrial

Day care. Day care occupancies include all buildings or portions of buildings in which four or more clients receive care, maintenance, and supervision, by other than their relatives or legal guardians, for less than twenty-four hours per day.

Day care occupancies include the following:

Child day care occupancies

Adult day care occupancies, except where part of a health care occupancy

Nursery schools

Day care homes

Kindergarten classes that are incidental to a child day care occupancy

In areas when public schools offer only half-day kindergarten programs, many child day care occupancies offer state-approved kindergarten classes for children who require full day care. As these classes are normally incidental to the day care occupancy, the requirements of the day care occupancy should be followed.

Health care. Health care occupancies are those used for purposes such as medical or other treatment or care of persons suffering from physical or mental illness, disease, or infirmity and for the care of infants, convalescents, or infirm aged persons. Health care occupancies provide sleeping facilities for four or more occupants and are occupied by persons who are mostly incapable of self-preservation because of age, physical or mental disability, or because of security measures not under the occupants' control.

Health care occupancies include the following:

Hospitals

Nursing homes

Limited care facilities

Ambulatory health care. Ambulatory health care occupancies are those used to provide services or treatment simultaneously to four or more patients on an outpatient basis. The patients are considered incapable of self-preservation due to the treatment rendered, the use of anesthesia, or the injury for which they are receiving emergency or urgent care.

Detention and correctional. Detention and correctional occupancies are used to house individuals under varied degrees of restraint or security and are occupied by persons who are mostly incapable of self-preservation because of security measures not under the occupants' control.

Detention and correctional occupancies include the following:

Adult and juvenile substance abuse centers

Adult and juvenile work camps

Adult community residential centers

Adult correctional institutions

Adult local detention facilities

Juvenile community residential centers

Juvenile detention facilities

Juvenile training schools

Residential. Residential occupancies are those occupancies in which sleeping accommodations are provided for normal residential purposes and include all buildings designed to provide sleeping accommodations.

Exception. Those classified under health care or detention and correctional occupancies.

Residential occupancies are treated separately in Life Safety Code®, NFPA 101, 2015 edition, in the following groups:

One-family and two-family dwelling unit

Lodging or rooming house

Hotels

Dormitory

Apartment building

Residential board and care occupancy

Mercantile occupancy. An occupancy used for the display and sale of merchandise.

Mercantile occupancies include the following:

Office, storage, and service facilities incidental to the sale of merchandise and located in the same building should be considered part of the mercantile occupancy.

Business. Business occupancies are those used for the transaction of business other than those covered under mercantile.

Business occupancies include the following:

Doctors' and dentists' offices are included unless of such character as to be classified as ambulatory health care occupancies.

Industrial. Industrial occupancies include factories making products of all kinds and properties devoted to operations such as processing, assembling, mixing, packaging, finishing or decorating, and repairing.

Industrial occupancies include the following:

In evaluating the appropriate classification of laboratories, the authority having jurisdiction should determine each case individually based on the extent and nature of the associated hazards. Some laboratories may be classified as occupancies other than industrial, for example, a physical therapy laboratory or a computer laboratory.

Storage. Storage occupancies include all buildings or structures utilized primarily for the storage or sheltering of goods, merchandise, products, vehicles, or animals.

Storage occupancies include the following:\

Storage occupancies are characterized by the presence of relatively small numbers of persons in proportion to the area. Any new use that increases the number of occupants to a figure comparable with other classes of occupancy changes the classification of the building to that of the new use.

Multiple occupancies. A building or structure in which two or more classes of occupancy exists shall be classified as a multiple occupancy. Multiple occupancies must be protected either as mixed occupancies or as separated occupancies, in accordance with subsection 6.1-14.3 or 6.1-14.4, respectively, of Life Safety Code®, NFPA 101, 2015 edition. Where exit access from an occupancy traverses another occupancy, the multiple occupancy must be protected as a mixed occupancy. In implementing the mixed occupancies form of protection, the building must comply with the most restrictive requirements of the occupancies involved, unless separate safeguards are approved.

5. Occupant load factor table.

* Net floor area is the actual occupied area, not including accessory unoccupied areas or thickness of walls.

** Gross floor area is the floor area within the inside perimeter of the outside walls of the building under consideration with no deduction for hallways, stairs, closets, thickness of interior walls, columns, or other features.

Notes to occupant load table.

Note 1. Bleachers, pews, and similar bench-type seating: one person per eighteen linear inches.

Note 2. Fixed seating. The occupant load of an area having fixed seats shall be determined by the number of fixed seats installed. Required aisle space serving the fixed seats shall not be used to increase the occupant load.

Note 3. Refer to chapters 32 and 33 of Life Safety Code®, NFPA 101, 2015 edition.

Note 4. Occupant load factors associated with the use.

6. Building classification table.

x - indicates required

o - indicates not required

Special structures (refer to chapter 11. Life Safety Code®, NFPA 101, 2015 edition).

Mixed occupancies (Note 5).

NOTES:

Note 1. Exception: Power supply for exit and emergency lighting shall conform to NFPA 110.

Note 2. Exception: Where each guest room, guest suite, or resident sleeping room has an exit direct to the outside of the building at street or ground level emergency lighting is not required.

Note 3. Exception: Buildings with only one exit need not be provided with exit signs.

Note 4. Exception: Where the same means of egress serve multiple use or combined occupancies, exit lighting, exit signs, and emergency lighting shall be provided for the occupancy with the most stringent lighting requirements. The occupant load of each type of occupancy shall be added to arrive at the total occupant load.

Note 5. Exception: Where an exit is immediately apparent from all portions of the sales area, the exit marking is not required.

Note 6. Exception: Special purpose industrial occupancies without routine human habitation.

Note 7. Exception: Structures occupied only during daylight hours, with skylights or windows arranged to provide the required level of illumination on all portions of the means of egress during these hours.

Note 8. Exception: Storage occupancies do not require emergency lighting when not normally occupied.

Note 9. Exception: In structures occupied only during daylight hours, with skylights or windows arranged to provide the required level of illumination of all portions of the means of egress during these hours, emergency lighting is not required.

Fire Alarm System Condensed Guide

O - NOT required X - required

Industrial - Check with the local fire authority or the state fire marshal Office building - Check with local jurisdiction

*State Department of Health rules.

Note 1. Placement of devices must be at exit on each level.

Note 2. Detectors required in each sleeping room and one detector for each seventy-five feet [22.86 meters] of hallway.

Note 3. When automatic sprinklers and flow detectors are installed, they must be connected to the alarm system. Heat detectors are required in mechanical rooms, laundry rooms, and storerooms.

Note 4. Institutional includes hospitals, nursing homes, jails, and similar facilities, including any occupancy where movement is restricted.

Note 5. If equipped with sprinkler.

Note 6. Emergency voice alarm and signal.

Note 7. One hundred or more sprinkler heads.

All signaling devices for all occupancies must meet Americans with Disabilities Act (ADA) requirements (check ADA requirements).

Smoke detectors in hotels, motels, and apartments are not to be tied to the central alarm system (alarm in room or apartment only).

Central alarm trouble indicator must be located where it will be heard.

Systems with two or more zones must have an annunciator panel located at an entrance approved by the local fire department.

Cities shall have additional or more stringent requirements.

Be aware the table is the minimum and the owner or designer shall ask for more.

General Authority: NDCC 43-09-05

Law Implemented: NDCC 43-09-21, 43-09-22