- Feeders shall originate in a distribution center. The conductors shall be run as multi conductor cord or cable assemblies or within raceways; or, where not subject to physical damage, they may be run as open conductors on insulators not more than 10 feet (3.05m) apart.
- Branch circuits shall originate in a power outlet or panel board.
- Receptacles shall be of the grounding type. Receptacles for uses other than temporary lighting shall not be installed on branch circuits which supply temporary lighting. Receptacles shall not be connected to the same ungrounded conductor of multi-wire circuits which supply temporary lighting.
- Disconnecting switches or plug connectors shall be installed to permit the disconnection of all ungrounded conductors· of each temporary circuit.
- All lamps for general illumination shall be protected from accidental contact or breakage.
- Temporary lights shall not be suspended by their electric cords unless cords and lights are designed for this means of suspension.
- All pull boxes, junction boxes, and fittings shall be provided with covers. In energized installations each outlet box shall have a cover, faceplate, or fixture canopy.
- Complete enclosure. Boxes shall provide a complete enclosure for the contained conductors or cables.
|1926.405 Wiring Methods, components, and equipment for general use.|
The provisions of this paragraph do not apply to conductors which form an integral part of equipment such as motors, controllers, motor control centers and like equipment.
General requirements – ( i ) Electrical continuity of metal raceways and enclosures, metal raceways, cable armor, and other metal enclosures for conductors shall be metallically joined together into a continuous electric conductor and shall be so connected to all boxes, fittings and cabinets as to provide effective electrical continuity.
( ii ) Wiring in ducts. No wiring systems of any type shall be installed in ducts used to transport dust, loose stock or flammable vapors. No wiring system of any type shall be installed in any duct used for vapor removal or in any shaft containing only such ducts.
Temporary wiring – ( i ) Scope. The provisions of paragraph ( a) ( 2 ) of this section apply to temporary electrical power and lighting wiring methods which may be of a class less than would be required for a permanent installation. Except as specifically modified in paragraph (a) ( 2) of this section, all other requirements of this subpart for permanent wiring shall apply to temporary wiring installations. Temporary wiring shall be removed immediately upon completion of construction or the purpose for which the wiring was installed.
( ii ) General requirements for temporary wiring – ( A ) Feeders shall originate in a distribution center. The conductors shall be run as multi conductor cord or cable assemblies or within raceways: or, where not subject to physical damage, they may be run as open conductors on insulators not more than 10 feet ( 3.05 m ) apart.
B) Branch circuits shall originate in a power outlet or panel board. Conductors shall be run as multi conductors cord or cable assemblies or open conductors, or shall be run in raceways. All conductors shall be protected by overcurrent devices at their ampacity. Runs of open conductors shall be located where the conductors will not be subject to physical damage, and the conductors shall be fastened at intervals not exceeding 10 feet ( 3.05 m ). No branch- circuit conductors shall be laid on the floor. Each branch circuit that supplies receptacles or fixed equipment shall contain a separate equipment grounding conductor if the branch circuit is run as open conductors.
C) Receptacles shall be of the grounding type. Unless installed in a complete metallic raceway, each branch circuit shall contain separate equipment grounding conductor, and all receptacles shall be electrically connected to the grounding conductor. Receptacles for uses other than temporary lighting shall not be installed on branch circuits which supply temporary lighting. Receptacles shall not be connected to the same ungrounded conductor of multiwire circuits which supply temporary lighting.
D) Disconnecting switches or plug connectors shall be installed to permit the disconnection of all ungrounded conductors of each temporary circuit.
E) All Lamps for general illumination shall be protected from accidental contact or breakage. Metal- case sockets shall be grounded.
F) Temporary lights shall not be suspended by their electric cords unless cords and lights are designed for this means of suspension.
G) Portable electric lighting used in wet and/or other conductive locations, as for example, drums, tanks, and vessels, shall be operated at 12 volts or less. However, 120- volt lights may be used if protected by a ground- fault circuit interrupter.
H) A box shall be used wherever a change is made to a raceway system or a cable system which is metal clad or metal sheathed.
I) Flexible cords and cables shall be protected from damage. Sharp corners and projections shall be avoided. Flexible cords and cables may pass through doorways or other pinch points, if protection is provided to avoid damage.
J) Extension cord sets used with portable electric tools and appliances shall be of three-wire type and shall be designed for hard or extra-hard usage. Flexible cords used with temporary and portable lights shall be designed for hard or extra-hard usage.
Note: The National Electrical Code, ANSI/NFPA 70, in Article 400, Table 400-4, list various types of flexible cords, some of which are noted as being designed for hard or extra-hard usage. Examples of these types of flexible cords include hard service cord ( type S, ST, SO, STO ) and junior hard service cord ( types SJ, SJO, SJT, SJTO ).
( iii ) Guarding. For Temporary wiring over 600 volts, nominal, fencing, barriers, or other effective means shall be provided to prevent access of other than authorized and qualified personnel.
Cabinets, boxes and fittings. 1) Conductors entering boxes, cabinets, or fitting. Conductors entering boxes, cabinets; or fittings shall be protected from abrasion, and openings through which conductors enter shall be effectively closed. Unused openings in cabinets, boxes and fittings shall also be effectively closed.
2) Covers and canopies. All pull boxes, junction boxes, and fittings shall be provided with covers. If metal covers are used, they shall be grounded. In energized installations each outlet box shall have a cover, faceplate, or fixture canopy. Covers of outlet boxes having holes through which flexible cord pendants pass shall be provided with bushings designed for the purpose or shall have smooth, well-rounded surfaces on which the cords may bear.
3) Pull and junction boxes for systems over 600 volts, nominal. In addition to other requirements in this section for pull and junction boxes, the following shall apply to these boxes for systems over 600 volts, nominal:
i) Complete enclosure. Boxes shall provide a complete enclosure for the contained conductors or cables.
ii) Covers. Boxes shall be closed by covers securely fastened in place. Underground box covers that weigh over 100 pounds ( 43.6 kg ) meet this requirement. Covers for boxes shall be permanently mark “ HIGH VOLTAGE.” The marking shell be on the outside of the box cover and shall be readily visible and legible.
Knife switches. Single-throw knife switches shall be so connected that the blades are dead when the switch is in the open position. Single-throw knife switches shall be so placed that gravity will not tend to close them. Single-throw knife switches approved for use in the inverted position shall be provided with a locking device that will ensure that the blades remain in the open position when so set. Double-throw knife switches may be mounted so that the throw will be either vertical or horizontal. However, if the throw is vertical, a locking device shall be provided to ensure that the blades remain in the open position when so set.
Switchboards and panel boards. Switchboards that have any exposed live parts shall be located in permanently dry locations and accessible only to qualified persons. Panel boards shall be mounted in cabinets, cutout boxes, or enclosures designed for the purposes and shall be dead front. However, panel boards other than the dead front externally-operable types are permitted where accessible only to qualified persons. Exposed blades of knife switches shall be dead when open.
Enclosures for damp or wet locations. 1) Cabinets, fittings, and boxes. Cabinets, cutout boxes, fittings, boxes, and panel boards enclosures in damp or wet locations shall be installed so as to prevent moisture or water from entering and accumulating within the enclosures. In wet locations the enclosures shall be weatherproof.
2) Switches and circuit breakers. Switches, circuit breakers, and switchboards installed in wet locations shall be enclosed in weatherproof enclosures.
f) Conductors for general wiring. All conductors used for general wiring shall be insulated unless otherwise permitted in this Subpart. The conductor insulation shall be of a type that is suitable for the voltage, operating temperature, and location of use. Insulated conductors shall be distinguishable by appropriate color or other means as being grounded conductors, ungrounded conductors, or equipment grounding conductors.
g) Flexible cords and cables. 1) Use of flexible cords and cables – i) Permitted uses. Flexible cords and cables shall be suitable for conditions of use and locations. Flexible cords and cables shall be used only for:
B) Wiring of fixtures;
C) Connection of potable lamps or appliances;
D) Elevator cables;
E) Wiring of cranes and hoists;
F) Connection of stationary equipment to facilitate their frequent interchange;
G) Prevention of the transmission of noise or vibration; or
H) Appliances where the fastening means and mechanical connections are designed to permit removal for maintenance and repair.
ii) Attachment plugs for cords: If used as permitted in paragraphs (g ) ( 1 ) ( i ) ( C ), ( g ) ( 1 ) ( i ) ( H ) of this section, the flexible cord shall be equipped with an attachment plug and shall be energized from a receptacle outlet.
iii) Prohibited uses. Unless necessary for a use permitted in paragraph (g) (1 ) ( i ) of this section, flexible cords and cables shall not be used:
As a substitute for the fixed wiring of a structure;
Where run through holes in walls, ceilings, or floor;
Where run through doorways, windows, or similar openings, except as permitted in paragraph (a) (2) (ii) (1) of this section;
Where attached to buildings surfaces; or
Where concealed behind building walls, ceilings, or floors.
2) Identification, splices, and terminations – (i) Identifications. A conductor of a flexible cord or cable that is used as a grounded conductor or an equipment grounding conductor shall be distinguishable from other conductors.