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hall have adequate mechanical strength. ENHANCED CONTENT Collapse When a significant load is added, such as electric vehicle power transfer equipment, the serving electric utility should be notified to ensure that adequate capacity is available. (B) Minimum Size. The conductors shall not be smaller...

hall have adequate mechanical strength. ENHANCED CONTENT Collapse When a significant load is added, such as electric vehicle power transfer equipment, the serving electric utility should be notified to ensure that adequate capacity is available. (B) Minimum Size. The conductors shall not be smaller than 8 AWG copper or 6 AWG aluminum or copper- clad aluminum. Exception: Conductors supplying only limited loads of a single branch circuit ? such as small polyphase power, controlled water heaters, and similar loads ? shall not be smaller than 12 AWG hard-drawn copper or equivalent. (C) Grounded Conductors. The grounded conductor shall not be less than the minimum size as required by 250.24(D). 230.24 Clearances. Overhead service conductors shall not be readily accessible and shall comply with 230.24(A) through (E) for services not over 1000 volts, nominal. (A) Above Roofs. Conductors shall have a vertical clearance of not less than 2.6 m (8 ft 6 in.) above the roof surface. The vertical clearance above the roof level shall be maintained for a distance of not less than 900 mm (3 ft) in all directions from the edge of the roof. Exception No. 1: The area above a roof surface subject to pedestrian or vehicular traffic shall have a vertical clearance from the roof surface in accordance with the clearance requirements of 230.24(B). Exception No. 2: Where the voltage between conductors does not exceed 300 and the roof has a slope of 100 mm in 300 mm (4 in. in 12 in.) or greater, a reduction in clearance to 900 mm (3 ft) shall be permitted. Exception No. 3: Where the voltage between conductors does not exceed 300, a reduction in clearance above only the overhanging portion of the roof to not less than 450 mm (18 in.) shall be permitted if (1) not more than 1.8 m (6 ft) of overhead service conductors, 1.2 m (4 ft) horizontally, pass above the roof overhang, and (2) they are terminated at a through-the- roof raceway or approved support. Informational Note: See 230.28 for mast supports. Exception No. 4: The requirement for maintaining the vertical clearance 900 mm (3 ft) from the edge of the roof shall not apply to the final conductor span where the service drop or overhead service conductors are attached to the side of a building. Exception No. 5: Where the voltage between conductors does not exceed 300 and the roof area is guarded or isolated, a reduction in clearance to 900 mm (3 ft) shall be permitted. ENHANCED CONTENT Collapse Exception No. 2. A steeply sloped roof (not less than 4 inches vertically in 12 inches horizontally), as illustrated below, is less likely to be walked on. The conductors? length over the roof is not restricted. Exception No. 3. This reduction is for service-mast (through-the-roof) installations where the mast is located within 4 feet of the edge of the roof, measured horizontally, as illustrated below. Exception No. 3 applies to the overhanging portion of sloped and flat roofs. The length of conductors that pass over the roof is not permitted to exceed 6 feet. Exception No. 4. The final span of service drop or overhead service conductors attached to the side of a building is exempt from the 8-foot and 3-foot clearance requirements to allow the service conductors to be attached to the building, as illustrated below. Vertical Clearance for Overhead Service Conductors. Overhead service conductors, where not in excess of 1000 volts, nominal, shall have the following minimum clearance from final grade: 3.0 m (10 ft) ? at the electrical service entrance to buildings, also at the lowest point of the drip loop of the building electrical entrance, and above areas or sidewalks accessible only to pedestrians, measured from final grade or other accessible surface only for overhead service conductors supported on and cabled together with a grounded bare messenger where the voltage does not exceed 150 volts to ground 3.7 m (12 ft) ? over residential property and driveways, and those commercial areas not subject to truck traffic where the voltage does not exceed 300 volts to ground 4.5 m (15 ft) ? for those areas listed in the 3.7 m (12 ft) classification where the voltage exceeds 300 volts to ground 5.5 m (18 ft) ? over public streets, alleys, roads, parking areas subject to truck traffic, driveways on other than residential property, and other land such as cultivated, grazing, forest, and orchard 7.5 m (241?2 ft) over tracks of railroads ENHANCED CONTENT Collapse The exhibit below illustrates the required 10-foot, 12-foot, 15-foot, and 18-foot vertical clearances from ground for overhead service conductors up to 1000 volts. The voltages given are nominal voltages to ground, not the nominal voltage between circuit conductors specified in 230.24(A), Exceptions No. 2 and No. 3. A 480Y/277-volt system (277 volts to ground) is covered by the 12-foot clearance requirement in 230.24(B)(2), but overhead service conductors supplied by an ungrounded 480-volt system (considered to be 480 volts to ground) are required to have a 15-foot clearance over commercial areas not subject to truck traffic, in accordance with 230.24(B)(3). (C) Clearance from Building Openings. Clearances from building openings shall comply with 230.9(C). (D) Clearance from Swimming Pools, Fountains, and Similar Installations. Clearances from swimming pools, fountains, and similar installations shall comply with 680.9. (E) Clearance from Communication Wires and Cables. Clearance from communication wires and cables shall be in accordance with 800.44(A)(4). 230.26 Point of Attachment. The point of attachment of the overhead service conductors to a building or other structure shall provide the minimum clearances as specified in 230.9 and 230.24. In no case shall this point of attachment be less than 3.0 m (10 ft) above finished grade. 230.27 Means of Attachment. Multiconductor cables used for overhead service conductors shall be attached to buildings or other structures by fittings identified for use with service conductors. Open conductors shall be attached to fittings identified for use with service conductors or to noncombustible, nonabsorbent insulators securely attached to the building or other structure. ENHANCED CONTENT Collapse See also 230.51 for mounting and supporting of service cables and individual open service conductors. For connections at service heads, see 230.54. 230.28 Service Masts as Supports. Only power service-drop or overhead service conductors shall be permitted to be attached to a service mast. Service masts used for the support of service-drop or overhead service conductors shall be installed in accordance with 230.28(A) and (B). (A) Strength. The service mast shall be of adequate strength or be supported by braces or guy wires to withstand safely the strain imposed by the service-drop or overhead service conductors. Hubs intended for use with a conduit that serves as a service mast shall be identified for use with service-entrance equipment. (B) Attachment. Service-drop or overhead service conductors shall not be attached to a service mast between a weatherhead or the end of the conduit and a coupling, where the coupling is located above the last point of securement to the building or other structure or is located above the building or other structure. ENHANCED CONTENT Collapse If the service drop is secured to the mast, a guy wire may be needed to support the mast and provide the required mechanical strength to support the service drop. The service drop is not permitted to be secured to the mast between the weatherhead or end of the conduit and a coupling installed above the last point where the conduit is secured to a building or structure. Securing the conductors above the fitting could put undue stress on the assembly. Communications conductors such as those for cable television or telephone service are not permitted to be attached to the service mast. 230.29 Supports over Buildings. Service conductors passing over a roof shall be securely supported by substantial structures. For a grounded system, where the substantial structure is metal, it shall be bonded by means of a bonding jumper and listed connector to the grounded overhead service conductor. Where practicable, such supports shall be independent of the building. Part III. Underground Service Conductors 230.30 Installation. (A) Insulation. Underground service conductors shall be insulated for the applied voltage. Exception: A grounded conductor shall be permitted to be uninsulated as follows: * (1) Bare copper used in a raceway * (2) Bare copper for direct burial where bare copper is approved for the soil conditions * (3) Bare copper for direct burial without regard to soil conditions where part of a cable assembly identified for underground use * (4) Aluminum or copper-clad aluminum without individual insulation or covering where part of a cable assembly identified for underground use in a raceway or for direct burial (B) Wiring Methods. Underground service conductors shall be installed in accordance with the applicable requirements of this Code covering the type of wiring method used and shall be limited to the following methods: * (1) RMC conduit * (2) IMC conduit * (3) Type NUCC conduit * (4) HDPE conduit * (5) PVC conduit * (6) RTRC conduit * (7) Type IGS cable * (8) Type USE conductors or cables * (9) Type MV or Type MC cable identified for direct burial applications * (10) Type MI cable where suitably protected against physical damage and corrosive conditions * (11) Type TC-ER cable where identified for service entrance use and direct burial applications 230.31 Size and Ampacity. (A) General. Underground service conductors shall have sufficient ampacity to carry the current for the load as calculated in accordance with Parts II through V of Article 220. (B) Minimum Size. The conductors shall not be smaller than 8 AWG copper or 6 AWG aluminum or copper- clad aluminum. Exception: Conductors supplying only limited loads of a single branch circuit ? such as small polyphase power, controlled water heaters, and similar loads ? shall not be smaller than 12 AWG copper or 10 AWG aluminum or copper-clad aluminum. (C) Grounded Conductors. The grounded conductor shall not be smaller than the minimum size required by 250.24(D). ENHANCED CONTENT Collapse See also 310.15(D) for the allowable ampacity of bare and covered conductors. For further information on sizing the grounded conductor for dwelling services, 310.12(D). 230.32 Protection Against Damage. Underground service conductors shall be protected against damage in accordance with 300.5. Service conductors entering a building or other structure shall be installed in accordance with 230.6 or protected by a raceway wiring method identified in 230.43. 230.33 Spliced Conductors. Service conductors shall be permitted to be spliced or tapped in accordance with 110.14, 230.46, 300.5(E), 300.13, and 300.15. Part IV. Service-Entrance Conductors 230.40 Number of Service-Entrance Conductor Sets. Each service drop, set of overhead service conductors, set of underground service conductors, or service lateral shall supply only one set of service-entrance conductors. Exception No. 1: A building with more than one occupancy shall be permitted to have one set of service- entrance conductors for each service, as permitted in 230.2, run to each occupancy or group of occupancies. If the number of service disconnect locations for any given classification of service does not exceed six, the requirements of 230.2(E) shall apply at each location. If the number of service disconnect locations exceeds six for any given supply classification, the following conditions shall apply: * (1) All service disconnect locations for all supply characteristics, together with any branch circuit or feeder supply sources, shall be clearly described using graphics or text, or both, on one or more plaques * (2) The plaques shall be located in an approved, readily accessible location(s) on the building or structure served and as near as practicable to the point(s) of attachment or entry(ies) for each service drop or service lateral and for each set of overhead or underground service conductors. Exception No. 2: Where two to six service disconnecting means in separate enclosures are grouped at one location and supply separate loads from one service drop, set of overhead service conductors, set of underground service conductors, or service lateral, one set of service- entrance conductors shall be permitted to supply each or several such service equipment enclosures. Exception No. 3: A one-family dwelling unit and its accessory structures shall be permitted to have one set of service-entrance conductors run to each from a single service drop, set of overhead service conductors, set of underground service conductors, or service lateral. Exception No. 4: Two-family dwellings, multifamily dwellings, and multiple occupancy buildings shall be permitted to have one set of service-entrance conductors installed to supply the circuits covered in 210.25. Exception No. 5: One set of service-entrance conductors connected to the supply side of the normal service disconnecting means shall be permitted to supply each or several systems covered by 230.82(5) or 230.82(6). ENHANCED CONTENT Collapse Exception No. 1. If.a building has more than one occupancy ? such as multifamily dwellings, strip malls, and office buildings ? each service drop, set of overhead service conductors, set of underground service conductors, or service lateral is allowed to supply more than one set of service-entrance conductors, provided they are run to each occupancy or group of occupancies. This requirement allows for multiple service disconnecting means locations for each service that supplies the building or structure. Based on this exception, one service can be arranged similarly to a building or structure that is supplied by multiple services. The exception does not limit the number of disconnecting means locations supplied by each service. Because this exception permits more than one service equipment location on a single building or structure, a plaque or directory with information about the multiple equipment locations is required to be provided at each location. If the number of service equipment locations for any class of service exceeds six, a master plaque(s) or directory(s) is required near the point where service conductors attach to or enter a building or structure. The information must describe the multiple service equipment locations using text, a graphic, or a combination. At the individual service equipment locations, the general marking required in 230.70(B) must be provided. For example, if a mercantile building has eight storefronts and the building is supplied by a single 208Y/120-volt service, eight sets of service-entrance conductors can be installed with one set run to each occupancy. The service equipment at each occupancy can have up to six service disconnecting means in accordance with 230.71. Because the number of service disconnecting means locations for this service exceeds six, a permanent plaque(s) identifying the multiple supply equipment locations is required. The location of the plaque must be acceptable to the AHJ. Exception No. 3. A second set of service-entrance conductors supplied by a single service drop or lateral at a single-family dwelling unit is permitted to supply another building on the premises, such as a garage or storage shed. The utility meters may be grouped at one location, but in this application, the service disconnecting means are not required to be grouped at one location. 230.41 Insulation of Service-Entrance Conductors. Service-entrance conductors entering or on the exterior of buildings or other structures shall be insulated. Exception: A grounded conductor shall be permitted to be uninsulated as follows: * (1) Bare copper used in a raceway or part of a service cable assembly * (2) Bare copper for direct burial where bare copper is approved for the soil conditions * (3) Bare copper for direct burial without regard to soil conditions where part of a cable assembly identified for underground use * (4) Aluminum or copper-clad aluminum without individual insulation or covering where part of a cable assembly or identified for underground use in a raceway, or for direct burial * (5) Bare conductors used in an auxiliary gutter 230.42 Minimum Size and Ampacity. (A) General. Service-entrance conductors shall have an ampacity of not less than the maximum load to be served. Conductors shall be sized not less than the largest of 230.42(A)(1) or (A)(2). Loads shall be determined in accordance with Part III, IV, or V of Article 220, as applicable. Ampacity shall be determined from 310.14 and shall comply with 110.14(C). The maximum current of busways shall be that value for which the busway has been listed or labeled. Informational Note: See UL 857, Standard for Safety for Busways, for information on busways. (1) Continuous and Noncontinuous Loads. Where the service-entrance conductors supply continuous loads or any combination of noncontinuous and continuous loads, the minimum service-entrance conductor size shall have an ampacity not less than the sum of the noncontinuous loads plus 125 percent of continuous loads. Exception No. 1: Grounded conductors that are not connected to an overcurrent device shall be permitted to be sized at 100 percent of the sum of the continuous and noncontinuous load. Exception No. 2: The sum of the noncontinuous load and the continuous load if the service-entrance conductors terminate in an overcurrent device where both the overcurrent device and its assembly are listed for operation at 100 percent of their rating shall be permitted. (2) Application of Adjustment or Correction Factors. The minimum service-entrance conductor size shall have an ampacity not less than the maximum load to be served after the application of any adjustment or correction factors. (B) Specific Installations. In addition to the requirements of 230.42(A), the minimum ampacity for ungrounded conductors for specific installations shall not be less than the rating of the service disconnecting means specified in 230.79(A) through (D). (C) Grounded Conductors. The grounded conductor shall not be smaller than the minimum size as required by 250.24(D). 230.43 Wiring Methods for 1000 Volts, Nominal, or Less. Service-entrance conductors shall be installed in accordance with the applicable requirements of this Code covering the type of wiring method used and shall be limited to the following methods: * (1) Open wiring on insulators * (2) Type IGS cable * (3) Rigid metal conduit (RMC) * (4) Intermediate metal conduit (IMC) * (5) Electrical metallic tubing (EMT) * (6) Electrical nonmetallic tubing * (7) Service-entrance cables * (8) Wireways * (9) Busways * (10) Auxiliary gutters * (11) Rigid polyvinyl chloride conduit (PVC) * (12) Cablebus * (13) Type MC cable * (14) Mineral-insulated, metal-sheathed cable, Type MI * (15) Flexible metal conduit (FMC) not over 1.8 m (6 ft) long or liquidtight flexible metal conduit (LFMC) not over 1.8 m (6 ft) long between a raceway, or between a raceway and service equipment, with a supply-side bonding jumper routed with the flexible metal conduit (FMC) or the liquidtight flexible metal conduit (LFMC) according to 250.102(A), (B), (C), and (E) * (16) Liquidtight flexible nonmetallic conduit (LFNC) * (17) High density polyethylene conduit (HDPE) * (18) Nonmetallic underground conduit with conductors (NUCC) * (19) Reinforced thermosetting resin conduit (RTRC) * (20) Type TC-ER cable where identified for use as service entrance conductors * (21) Flexible bus systems ENHANCED CONTENT Collapse Section 230.43(15) permits no more than 6 feet of flexible metal conduit or liquidtight flexible metal conduit to be used as a service wiring method. Because of the high levels of fault energy available on the line side of the service disconnecting means, a bonding jumper must be installed where these raceway types are used for service conductors. The bonding jumper is allowed to be installed inside or outside the raceway, but when installed outside the raceway it must follow the path of the raceway and cannot exceed 6 feet in length. To minimize the impedance of the ground-fault current return path, the bonding jumper must not be wrapped or spiraled around the flexible conduit. 230.44 Cable Trays. Cable tray systems shall be permitted to support service-entrance conductors. Cable trays used to support service-entrance conductors shall contain only service-entrance conductors and shall be limited to the following methods: * (1) Type SE cable * (2) Type MC cable * (3) Type MI cable * (4) Type IGS cable * (5) Single conductors 1/0 and larger that are listed for use in cable tray * (6) Type TC-ER cable Such cable trays shall be identified with permanently affixed labels with the wording ?Service-Entrance Conductors.? The labels shall be located so as to be visible after installation with a spacing not to exceed 3 m (10 ft) so that the service-entrance conductors are able to be readily traced through the entire length of the cable tray. Exception: Conductors, other than service-entrance conductors, shall be permitted to be installed in a cable tray with service-entrance conductors, provided a solid fixed barrier identified for use with the cable tray is installed to separate the service-entrance conductors from other conductors installed in the cable tray. 230.46 Spliced and Tapped Conductors. Service-entrance conductors shall be permitted to be spliced or tapped in accordance with 110.14, 300.5(E), 300.13, and 300.15. Power distribution blocks, pressure connectors, and devices for splices and taps shall be listed. Power distribution blocks installed on service conductors shall be marked ?suitable for use on the line side of the service equipment? or equivalent. Pressure connectors and devices for splices and taps installed on service conductors shall be marked ?suitable for use on the line side of the service equipment? or equivalent. ENHANCED CONTENT Collapse Splices must be in an enclosure or be direct buried using a listed underground splice kit. Splices are permitted where the cable enters a terminal box and a different wiring method, such as conduit, continues to the service equipment. Tapped sets of conductors are commonly used to supply multiple service disconnecting means installed in separate enclosures as permitted by 230.71. 230.50 Protection Against Physical Damage. (A) Underground Service-Entrance Conductors. Underground service-entrance conductors shall be protected against physical damage in accordance with 300.5. (B) All Other Service-Entrance Conductors. All other service-entrance conductors, other than underground service entrance conductors, shall be protected against physical damage as specified in 230.50(B)(1) or (B)(2). (1) Service-Entrance Cables. Service-entrance cables, where subject to physical damage, shall be protected by any of the following: * (1) Rigid metal conduit (RMC) * (2) Intermediate metal conduit (IMC) * (3) Schedule 80 PVC conduit * (4) Electrical metallic tubing (EMT) * (5) Reinforced thermosetting resin conduit (RTRC) * (6) Other approved means (2) Other Than Service-Entrance Cables. Individual open conductors and cables, other than service-entrance cables, shall not be installed within 3.0 m (10 ft) of grade level or where exposed to physical damage. Exception: Type MI and Type MC cable shall be permitted within 3.0 m (10 ft) of grade level where not exposed to physical damage or where protected in accordance with 300.5(D). 230.51 Mounting Supports. Service-entrance cables or individual open service-entrance conductors shall be supported as specified in 230.51(A), (B), or (C). (A) Service-Entrance Cables. Service-entrance cables shall be supported by straps or other approved means within 300 mm (12 in.) of every service head, gooseneck, or connection to a raceway or enclosure and at intervals not exceeding 750 mm (30 in.). (B) Other Cables. Cables that are not approved for mounting in contact with a building or other structure shall be moun