GLOSSARY Accessible: Not permanently concealed or enclosed by building con: of equipment can be considered accessible even if tools must be u! equipment must be removed to gain access to it. Accessible, readily: Capable of being reached quickly for operation or inspection Without the use of tools or portable ladders or the need to remove obstacles. Approved: Acceptable to the Authority Having Jurisdiction (AHJ). The AHJ wil usually ‘approve materials that are listed and labeled. ‘Arc fault; An electric current propagated through ait Arc-Fault Circuit interrupter (AFCI): A device intended to provide fire protection by recognizing arc characteristics and de-energizing the circuit when arcing occurs. Authority Having Jurisdiction (AHS): The building official or persons authorized to act on his or her behalf Bonded, bonding: Connected to establish continuity and conductivity. Branch circuit: The circuit conductors located between the last OCPD (breaker or fuse) and the outlet or outlets protected by the OCPD. * Branch circuit, general purpose: Branch circuit that supplies 2 or more receptacles or outlets for lighting and appliances. + Branch circuit, individual: Branch circuit that supplies only 1 piece of equipment. = Branch circuit, multiwire, residential: Branch circuit consisting of 2 hot conductors having 208V or 240V potential between them and a grounded neutral having 120V potential to each hot conductor F 19. * Branch circuit, small appliance: Branch circuit that supplies portable house- hold appliances in kitchens and related rooms. Device: A piece of equipment that carries or controls electrical energy as its primary function, such as a switch, receptacle, or circuit breaker. Equipment grounding conductor (EGC): A wire or conductive path that limits volt- ‘age on metal surfaces and provides a path for fault currents F1/ Feeders: Conductors that supply panelboards other than service panels. Flexibility after installation: Anticipated movement after initial installation, such a that caused by motor vibration or equipment repositioning, Ground, grounded: The earth, connected to earth, Ground fault: An unintentional connection of a current-carrying conductor to equip ; ‘earth, or conductors that are not normally intended to carry current. d or other t=) AUP Leda struction. A pioce wy © Ground-Fault Circuit Interrupter (GFCI: A device to protect against shock hazards by interrupting current when an imbalance of 6 millamps or more is detected. Grounded conductor: A current-carrying conductor the earth (a neutral). Grounding electrode conductor (GEC): A neutral or the equipment to a grounding « electrode system Fs Interrupting rating: The highest current an O without sustaining damage. Luminaire (formerly lighting ficture): A complate lighting unit inclucin 8 intentionally connected to tor used to connect the se of to a point on the grounding ar of fuse) can interrupt connect it to the power supply and possibly parts to protect or distribute the light source. A lampholder, such as a porcelain socket, is nat itself a luminaire Neutral conductor: The conductor connected to the neutral point of a system and that is intended to carry current under normal operating conditions Outlet: The point on a wiring system at which current is taken to supply equipment. A box for a receptacle, luminaire (fisture), or smoke alarm is an outlet; most baxes for switches are not outlets. Overcurrent: Any current in excess of the rating of equipment, device, or conductor ampacity. Overcurrents are produced by overaads, ground faults, or short circuits. Overfusing: A fuse or breaker that has an overload rating greater than allowed for the conductor or equipment itis protecting Overload: Equipment drawing current in excess of the equi ment or conductor rating and in such a manner that damage or dangerous conditions would occur if it contin- ued for a sufficient time, Short circuits and ground faults are not overloads. Service: The conductors and equipment providing a connection to the utility Service drop: The overhead conductors supplied by the utility Service equipment: The equipment at which the power conductors entering the building can be switched off to disconnect the premises’ wiring from the utility power source. A meter can be a part of or separate from the service equipment. Underground conductors from the utility to the service point Fs. direct connection of current-carrying conductors without the inter- position of a load, resulting in high levels of current Short Circuit Current Rating (SCCR): The amount of current that panelboards and switchboards must be able to carry during a short circuit condition without sustaining damage. See Interrupting rating. S @ TABLE OF CONTENTS ¢@ GLOSSARYService drop conductors are protected by isolation; they typically have no protec- tive outer jacket and no overload protection at their source. Utility rules may over- fide the specifications in the code, so check with the AHJ to determine variations from the clearances below. These clearances also apply to overhead feeders. Vertical above Roof Fi 17 NEC (0 <4:in-12 slope: min 8 ft. EM EXC 230.240 +3 ft. OK if roof area guarded or isolated 230,24AX5 (2 4:in-12 slope: min 3 ft. EB EXC ___230.24AX2 = Over eaves 18 in. OK for $4 ft. horizontal 6 ft. ‘of conductor [a] 230.24AX3 (0 Maintain req'd distance for 3 ft. past roof edge EXC. 230.244 + Edge clearance above roof is not req'd where overhead conductors attach to side of building _____________— 230.24AX4 CE Metal support structures for conductors passing over , roofs req bonding to neutral of service drop reg'd = required Vertical above Grade F1 17 NEC 1 10 ft. above final grade to lowest point of drip loop _ 230.2481 1 Area accessible only to pedestrians: 10 ft. 230.2481 CO General above grade & driveways: 12 #. Fa 230.2482 1 Above roads or parking areas subject 230.2484 to truck traffic: 18 ft. 1 Any direction < 10 ft. horizontal from swimming pool water: 22/2 ft._680.6A Clearance from Openings & Communication Wires Ft 17 NEC Vertical above decks & balconies: 10 ft. 230.98 __.230.9A From side of area above decks & balconies: 3 ft. 1 Below or to sides of openable window: 3 ft. a __ 230.94 (0 Communications wire min 12 in. to paraliel power wires 800.4444 1 Communications wires above roofs same as power conductors_ 800.448 Window & door clearances apply to open conductors-not lo conductors con ble with an overall outer jacket. Clea ically per the local utility_ SERVICE ENTRANCE CONDUCTORS The splice at the weatherhead from the service dro to the building wiring is typically the “service point"-the handoff ten he cay tease tomer. On overhead ‘systems, the conductors from the service point to the discon: necting means are service entrance conductors. Though the utility does not have exclusive Control of these conductors, they may still have jurisdiction over them. Dwelling unit service conductors & feeders that carry the entire load of the service are allowed to be sized in accordance with T14. The service must be large enough to meet the calculated load (see p.6-7) and for a SFD must be at least 100 amps. Service Riser 17 NEC ( Raceway size, material & bracing per utility, 90.20 CT Wiring method listed for electrical (no plumbing pipe) 110.3B & 230.43 C Listed for wet location & arranged to drain where exposed to weather 230.53 (1 Overhead raceway req's service head listed for wet locations 230.544 1 Riser req'd to have adequate strength & bracing 230.28A (1 No couplings between structural support & weatherhead 230.28B? TD Attachment of service drop below service head EXC 230.54C + OK up to 24 in. above when necessary (sidewall) 230.54CX Only power conductors on service risers—no communication cables _230.28 1 Conductor fill in raceway 40% T21 Ch 9-T18T4 Service Entrance Conductors. 17 NEC i Conductors & cables exposed to sunlight listed sunlight-resistant or covered with material listed as sunlightresistant 310.10D Identify both ends of neutral w/ white marking or tape 200.6B 1 No branch circuits or feeders in same raceway w/ service conductors 230.7 ( Conductors through separately bushed openings at service head, length per utility specifications 230.54E & 90.20 Gl Form drip loop in conductors 230.54F Service Entrance (SE) Cables 17 NEC Tl Where subject to damage, protect SE cables with RMC, IMC, PVC-80, EMT, or other approved means F56~-58. = ane 8 ble mit 80 in. O.C. & 12 in. from terminations ____ a oe ie head listed for wet locations EXC , Botts © «SE cable OK w/ gooseneck & taped connections "ee oy ‘Use waterproof gland or equivalent to prevent ee OO NS Service Entrance Conductor Size CO Conductor ampacity must meet load of 2,3 (p.6,7) 230.42 O Conductor ampacity per T11 (p.23) EXC 310. 15A * 63% of T11 allowed for SFD & individual units of ae 2family & multifamily dwellings T14 (p.23) 310.1587? O Sum of ratings of mains allowed to exceed T11 if Conductors adequate for calculated load per T2,3 SERVICE PANELS The switches, circuit breakers, or fuses that disconnect power from the utility at the customer's end of the service conductors are Part of the service equipment. A meter socket is not considered service equipment (230.66), though it may be with- inthe service equipment. Working space must be maintained at service equipment. 17 NEC 230.90AX3 General 17 NEC C0 Enclosure L&L as suitable for service equipment 230.68 NEMA enclosure type must be marked on equipment. 110.28 C1 No NEMA Type 1 (indoor use) equipment outdoors 110.26E2, 110.28 O Protect outdoor installations from vehicle traffic (bollards) 110.262 1 Max 6 disconnects to shut off power at service = 230.71 230.72 ( Disconnects must be grouped in one location CO Each service disconnect durably marked to indicate load served__ 230.724 1 Max height AFF of breaker or switch 6 ft. 7 in. 240.244 & 404.8A O Provide working space from face of enclosure EXC F2. __110.26A + Meter may extend into working space__110.26A3X2 (C Barriers req'd over supply terminals & buses in services EXC F16___408.3A2* + Buses & terminals of panels w/ 2 ~ 6 mains. 408.3A2X* 2-Family & Multifamily Dwellings (1 Only 1 service per building 230.2 C Adjoining units considered separate buildings if firewall separation. 100 1 Each occupant of multifamily to have access to their disconnect EXC _230.72C where under continuous building management supervision _280.72CX 0 2-tamily & multifamily dwellings req house meter for common areas 210.25B CO Senvice conductors may not pass through another building 230.3 swelling services can use a multimeter panel, or the service ay land 1 a “hot gutter” with splices ahead of separate in- ects, See p.10 for bonding requirements on such gutters. nly & mutttemWORKING SPACE SEPARATE BUILDINGS Working space is essential for wor std all election! equipment that fle wanes eee maintenance while energized. Working space should not be used for storage” General F2 17 NEC C Front working clearance min 36 in.deep 110.26A1 0 Distance measured from exposed live parts or face of enclosure__ 110.26A1 O Min headroom 61/2 ft. AFF or equipment height EXC. 110.2643 * Existing service equipment up to 200A OK < 81/2. 110.26A3X1 C Work space extends from floor to req'd height EXC 110.2643 * Related equipment may extend 6 in, beyond panel front _ 110.2643 O Clear width min 30 in. wide or width of equipment 110.2602 1 Equipment doors or hinged panels must be openable at least 90" 110,26A2 (CO Working space not to be used for storage ____ 110.268 1 Illumination req'd for working space at all indoor panels 110.260 Working Space around Equipment aco “ae 3 ft. min. depth measured from front 30in. min. ‘edge of panel width or width of equipment if > 30 in. Panel need not be centered in working space. Door must be copenable to at least 90°. Working space height 6 ft.6 in. AFF, or height of equipment, whichever Is greater Req'd working space must extend to floor or grade. UNDERGROUND i ONG CONGUGIOT TEMPORARY WIRING To avoid objectiorable currents on conductive paths betwaen buildings, an EGC. must be installed in addition to the insulated neutral feeder conductor. Existing installations with bonded noutrals can remain if there are no parallel current paths. Outside Feeders 17 NEC C0 Trees may not support overhead conductors 225,96 Ci Overhead feeder mast~same rules as services FY 225.17-19 7 Height above roofs < 4:12 slope 8 ft. 6 in. F1__ 225.1988 CO Provide proper cover for buried cable or conduit Fa, Tt 300.5 1 Each building or structure req’s GES F3, F6 EXC. 250.324 * Building or structure w/ only 1 branch circuit & w/ EGC 250,92AX C Raceways entering building from outside must be sealed. 225.27° Cl Max 1 feeder or branch circuit to or back from each building EXC__225.30 + EV chargers L&L for more than single branch circuit or feeder__225.30A7" 1 Disconnect req'd at each building F3 225.31 C1 Disconnect must consist of max 6 switches or breakers 225.33 C1 4-conductor feeder to panel in separate building~ do not bond neutral to EGC or GEC EXC 250.328 + Existing installations to separate buildings with no continuous metal paths, e.g, metal water pipe, ete., between the 2 structures _950.396X1 1 Disconnect rated as service equipment when using above exception 295.36 Separate Buildings Each building or structure containing more than 1 branch circuit req's its own GES. : Cover depth per T1 =" 4 Feeders to separate buildings reqan insulated neutral in addition to an EGC. Panels in separate buildings are subpanels F17.“UNDERGROUND WIRING = Fic. | Mighiua Da ee ‘Where underground conduits end on significantly different elevations, a drainage a box may be needed near the lower elevation to prevent water from rising up from the conduit. See p.24 for additional requirements for cable protection Generel Cover depth 17 NEC (measure from UO Cover from top of cable or conduit to finish grade per T1, Fa 300.54 top of conduit) ~ Service laterals concrete-encased or warning ribbon 12 in. above F4 300.53 | — SAUTION CauTioN | Warnit , | Jarning ribbon 12in. above service lateral 1 Backfill w/ smooth granular matorial-no rocks F4 soo. | conduit front rocks Sm 1 Provide running boards or sleeves if subject to damage from backtilFé 300.5 | (where necessary) se al 1 OK to splice o* tap direct-buried conductors w/out boxes where splicing means listed for the purpose (e.g, resin kits) 300.5E O Seal underground raceway entries at either or both ends __ 300.5G Spare or unused raceways also to be sealed aoosa General 17 NEC © All conductors of circuit in same trench o- raceway EXC 300.61 0 Allowed only during period of construction —_____590.3A * Parallel raceways OX if each raceway contains conductors Sewvices same height, grounding, clearance, etc.,. as permanent F1,5 590.4 ofall phases, neutrals, and EGC of circuit 300.51X1 (NM & SE allowed in any height building & SE OK underground _ 590.4B&C* ee asest Genet oun 1 No receptacles on branch circuits supplying temporary lighting 690.4D1 *S" loops, flexible connections &/or expansion fitings. 300.6) Cl Lampholdere req quarde_____________s90.4F i Cables & raceways for directional boring approved for O Splices in NM cable or MC cable OK without splice box if EGC 7 s rR seins typical reach MecnK continuity maintained (including listed metal cable fittings) 290.46 1 Interior of underground raceways considered a wet location goons © ©. Baste coras. 8 cables Rcey en—inuae aeege, —_—__—_— Cords & cables not OK on floor or ground exc extension cords 580.4)"* 1D Conductors installed underground must be L&L for wet locations _ 310.10C i GFCI req'd on all 125V 15, 20 & 30A temporary receptacles _590.6A1" 1 Listed GFCI cordsets OK only to supplement GFCI on temporary ea ime ustse sus ele cu ered receptacles or as first device on permanently wired receptacle _590.6A1&2"" GFCI = 208 C1 Other receptacles GFC\, special-purpose GFCI, or assured grounding 590.68" Circuit 12in. Gin, 6in. raceway* | raceway” ts Temporary Power Pole Typical 6x6 post with block above weatherhead Temporary power services follow the same NEC rules as permanent services as well as standards set by the utility GFCI receptaci UNDERGROUND pis te PN STi lel Pt Ta tet ORKING SPACELOAD CALCULATIONS _ SERVICE & FEEDER LOAD CALCULATIONS es LOAD CALCULA The calculation methods in the codes take into account th at not all of the | General Lighting & possible electrical loads will be used at the same time. Each of the calculation STDs & esvep ee bees methods allows the use of “demand factors” The “long form? shown below and 1 _ | 84.8 «SYA in 72, is the most common calculation method. For information on multifamily load | Small Applian calculations, refer to the examples in Annex D of the NEG. PRA 6 Re Eee : 2 [2 smal-appliance circuits 3,000 Load Calculation Steps (Long Form) T2 17 NEC —_e 1, Determine the sq. ft, area of the residence & multiply 3 _| Additional small appliance Ts by BVA (exclude garage & covered patios) 290.12 [4 _| Laundry circuit 1,500 2. Min 2 small-appliance circuits at 1,500VA each 220.52 5 | Subtotal general ight, 3. Each additional small-appliance circuit at 1,500VA 220.524 ‘mall appliance & laundry 4. Min 1 laundry circuit at 1,500VA 720828 [6 | pracnovA@ tome aa 5. Enter total of appliance circuits & general lighting 220.42 6. First 3,000VA counted at 100% (carries to right column) ya00.4o «| 2 Banos 628 7. Subtract 3,000 from amount in line 5 & enter difference in ‘Special Appliance Loads mile column Mutiplythemidle courn amount by 96%6& | aaron SSS enter in right column - __1220, 5 3,000 [or nameplate if>) 8. Range loads are calculated at nameplate rating. If a single range is Sa said cts > B,000VA & < 12,000VA, it still counts as 8,000VA (8kW). 10 | Heating or AC @ 100% if> 12,000VA, add 5% of each additional 1,000VA of Abpliandes Fastoned in Place nameplate load. Nameplates of a counter mounted range & 7) |W her up to 2 wall ovens can be added together & computed as if they : were 1 range. Enter in right column. 220.55 12 | Miecnere: 9. Enter dryer circuit at 5,000VA (or nameplate rating greater) __ 220.54 [19 | Dishwasher 40. Enter larger of fixed-space heating or AC load _____ 220.60 14 | Compactor 44-18. Enter nameplate ratings of appliances that are fixed in place. = lees For appliances rated in amps, multiply amps times voltage to determine ° fimatesinT4___——-22083-—«([ 16 | Atiofan watts. If nameplate ratings unknown, use estimates — 49. Enter total load of fixed appliances. a 220,68. 17_| Spa~per MFR. 20. If there are <4 fixed appliances, enter number from |ine 19 moss [12 [Oke in right column = 19 | Subtotal Jiances, multiply line 19 by 75% Picton sre = 8 Wind erpiion 22053 oo '<4 fied appliances, enter sublotal @100% or & enter in right column a assaaunoian 22, Add 25% of the largest moto load. Skip this stop Ha name 2 | 24 fod appliances, enter subtotal x 76% fated AC is largest load since that numbor has areacy ee as aa factored into nameplate min conductor ampacity 700,10) Total load 493. Add numbers in right column —_______ nen ee Sa era by 240 t0 find req'd min amperage — = [| ___Tetalload + 240V = SERVICE AMPS‘Size Requirements-General 47 NEC OOM sizeforSFD 100A 980,706 G Service conductors adequate forload tobe sewed 990.42 1 Service conductors allowed tobe 88% of T1183 10.15837 D Feeders adequate for load to be served 215.2M 1D Branch circuits adequate for max load to be served 210.1941 1D Optional method allowed 220.824 Optional Method (Short Form) 17 NEC 1. Multiply sq. ft. area by 3VA (exclude garage & covered patios)__ 220.8281 2. Min 2 smalFappliance circuits at 1,500VA each; each additional small-appiance circuit at 1,500VA 3. Min 1 laundry circuitat 1,500VA__ 4, Nameplate ratings of fixed appliances (see 4 if ratings not known); these include full nameplate rating of ranges & ovens without 220.8282 220.8282 ieee retort be ainpter€ cant applying reductions allowed in the “long form” method 220.8283 for expansion. These methods anply t & fe &: Entocetun of fis 324 Soonee 6. 100% of first 10,000VA 220.828 eet) Mrdogs cu ey 7. Subtract line 6 from line 5, multiply by 40% __ 220.828 1. Sq.ft. x 3VA 8. Determine largest of the Leow or cooling load. When using nameplate z ‘ rating of heat pumps or AC, multiply “minimum circuit ampacity” times a au eee ee SASH Nereh oe, the voltage (240). If only size (tonnage) is known, refer to T4 220.89C Baer Re 1 PO 1800. 9. Add numbers in right column & enter total 220.828 4._ Nameplate VA of fied appliances: 10. Divide line 9 by 240 = amperage Diyer @ 5,000VA Adding Loads to an Existing Dwelling ‘Ovenis) 1 If no new heating or AC equipment to be installed, acd the following and count the first 8. 000W @ 100% & the remainder @40%:__220.83 eee * SW per ft. (exclude garage & covered patios) seared + 1500W for each smali-appliance circuit and laundry circuit Dishwasher + Nameplate rating of all installed appliances or those for specific circuits Gapoor If new heating or AC equipment to be installed, add 100% of the larger of the heating or air conditioning to the above calculation 220.888, eee eS [8 First 10,000VA @ 100% Y X Use actual nameplate ratings when known, This table is for estimating Balance @ 40% (eubtract ine 6 from line 8) x4o|= purposes when appliances are not yet specified. 8 Largest of heating or cooling oad ‘Appliance Typical Appliance Typical Ba, Nameplate rating(s) of air-conditioning & cooling equipment OR Load (vA) Load (VA) ‘Bb, Hoat pump nameplate rating no supplemental electric host OR [Central AC 1,800/ton | Electric clothes dryer | 6,000 “Be. Continuous electric thermal storage @ nameplate rating OR Dishwasher 1,200 ‘Water heater 4,500 6 184. 100% of heal pump nameplate rating plus 66% of supplemental Disposer ‘300 Bectric cooktop 3.600 electric heat oF central elastic heat a Trash compactor 1,200 Single wall oven 4,800 ‘Be. Space heators @ 65% of nameplate rating if <4 units OR |__ Microwave 1,500 Double wall oven 8,000 “Bf. Space heaters @ 40% of nameplate rating t® 4 units P Gentral furnace 1,000 Pool pump 2,000 mg) Central vacuum 1,500 | Well pump 2,000GROUNDING ELECTRODES GROUNDING ELECTRODE CONDUCTORS Ga OK to use building steo! to imerconnect GECs Grounding Electrode Conductors panel Ufer Grounding provides a path for lightning and reduces electrical “noise” on commu nications equipment. Common grounding electrodes in residential construction are metal underground water piping, ground rods, and concrete-encased electrodes. Other types include ground rings, motel plates, metal well casings, listed grounding electrode eystems, underground tanks, and the steel frame of a building connected to earth as described below. Gas piping is not an acceptatle grounding electrode. Grounding Electrode System (GES) F6 17 NEC 1D Use all electrodes that are available on premises during the course of construction. 250.60 Bond al electrodes to form a GES 250.50 Dl Gas pipe not OK as grounding electrode 250.5281 Water Pipe 1 Use metal water pipe if 2 10 ft. in contact with soil F6 250.521 1 Bond around water meters, filters, etc, —_ 280.5301 Cl Water pipe cannot be the sole electrode-it must be ‘supplemented by another type of electrode _ 260.5802 1D Pipe, rod, or plate that supplements water pipe must comply with =, 25 ohm rule or be supplemented by another electrode 1D Metal well casing OK as electrode (e.g. plastic water service) __ 250.5248 Ground Ring J Min #2 copper encircling building in direct contact w/ earth F6 __ 250.52A4 Gi Min 20 in, below surface of earth __260.59F Metal In-Ground Building Structure i : Metal i jpport structures w/10 ft in drect contact ee aces 250.5242 ‘wi earth or encased in concrete in earth (ples) T Service| OK fo use water pipe within 5 ft. of entry to building to interconnect aR soeen OK to use Uler extension to interconnect GECs in location Single rod with resistance > 25 ohms must be supplemented by another electrode other than water pipe Water pipe w/10 ft. in GECs Ground Rods 17 NEC C1 Unlisted pipe electrodes min % in. diameter & galvanized 250.52A5a ( Copper-clad rods min Sis in. diameter unless listed for less _ 250.52A5b 1 Rods min 8 ft in contact with soil FS. __ 250.536 1 Drive rods vertical & fully below grade EXC = 250.536 + If bedrock encountered, rod may be buried horizontally 21/eft. deep or driven at 45° angle 250.536 + Clamp above grade OK if protected F8-10 250.536 C Must be supplemented by another electrode that is not a water pipe EXC. 250.5302 + Not req'd if rod resistance < 25 ohms. 250.53A2X Supplemental roda/plates spaced min 6 ft. apart (16 ft. preferred) _ 250.5A3 Concrete-Encased Electrode (Ufer) C1 Ufer = 20 ft. #4 or larger rebar near bottom of footing or 20 ft. of min #4 Cu wire near bottom of footing, min 2 in, encasement 280.523, Ci Ufer must be used if present during construction. 250.50 Ci Uter not req'd in existing building if concrete would have to be disturbed to gain access 250.50X 1 OK to bond sections of rebar with ordinary steel tie wires to obtain 20 ft. continuous length. 250.52A3, Cl Can be 20 it. of vertical stee! in pier in direct earth contact 250.5243 ( Where multiple Uters present, only 1 req’d to be bonded to GES_ 250.5243 Pipes & Plates CI Pipe clectrodes min 9/ in. diameter & galvanized. 250.5246 D1 Ferrous plates min "4 in, thick & min 2 sq.ft. in contact with sol_ 250.5247 C1 Aluminum not permitted as grounding electrode 2505262RS (GECs) The GEC that connects the system of metal grounding electrodes in earth to the Service Entrance Conductor (AWG) GEC (AWG) electrical eystem must have adequate size and protection. Individual GECs can ———— zi be run te each electrode of the GES, or a single GEC can be tun to one of them, wo fT a provided all the other GECs are connected by bonding conductors. Pr 1/0 a 6 — a 17 NEC orto “Boor s t_uiS=aE= rn ee ent 210 oF 3/0 4/0 of 250kemil & service neutral to the grounding electrodes__ 250.240 = = 1 Gonnect GEC to service neutral at any accessible point om ake iiae eet load end of service drop to neutral bus in service disconnect. 250.2401 > 360-600kemil > 500-900kemil Q Be AGE tot OKin stony oath 250.644 >800-1100kem’ | > 900-1750kemi1 ere outside, no Al ter ited within 18 in. of earth. 250.644 > 11 00kcmi > 1760kcmil 3/0 i T Connect GEC to metal water pipe that is continuous from ~ = underground $5. from point of pipe entrance to building F6__25068C1 Protection F7-10 17 NEC 1 Metal structural building frame OK to interconnect GECs 250.6802 —_—_[1 2 #6 req's protection if subject to physical damage EXC 2506482 1 Hold-down bolts of metal structural building frame OK as * If following building contour & not subject to damage F7. 250.6481 connection to Ufer w/ tie wires, welding, or other means 250.68C2"? D0 #8 always req's protection by raceway or armor F8 250.6483 1 Additional Ufer bar may extend through foundation to accessible 1 Bond each end of ferrous raceways enclosing GECs point for connection where not subject to corrosion F& 250.68C3"* to the enclosure or electrade or to the GEC F8. 250.6451 Mathode of Connection C Bond protective conduit using same methods as for 1 No splices between service & GES EXC 250.646 supply-side bonding (see p.10) Tae * Listed ireversible compression connectors or exothermic welding 260.640 __ If connection to red ie above grade and located where subject 250.596 Note: The GEC does net need to be continous ram one portion of the GES to another; individual conductors can connect to components of the GES Gi GEC can connect to any electrode of GES or GECs can to damage, protect with wood or metal enclosure Armor-clad GEC connect individually to electrodes comprising GES. = 250.64F Buried clamps L&l for direct burial (marked “DB") F6 250.70 1D Cuwater tubing clamps Lal for Cu tubing 250.70 DD Ufer clamps L&L for rebar & encasement FE 250.70 C Strap-type clamps suitable only for indoor #8 must be protected. telecommuricetions 250.70 > #6 following the aN asad 1D Max 1 conductor per clamp unless listed for more. _ 250.70 building contour does not bond motel Cl Connections must be accessible EXC 250.68A need protection. sheath to GEC, + Buried or encased connections 0 250.68AX1 Size . 1D Size bonding conductors that connect GES per GEC rules. 260.530 be! ici GEC in pve Gi Size GEC based on largest size req'd among . y all electrodes in the GES = —260.64F | Ferrous metal protective i Size GEC per sevice conductor size TS EXC_ 250.86 Sickive coal hae #46 Cu largest size needed if ending at rod or plate electrocie 56 ean nt bells erica iia . Pending stUler___—— PVC a simpler solution, #4 Cu largest size needed if ending ie + #2 Cu largest size needed if ending at ground ring GROUNDING ELECTRODE CONDUCTORS fe cm eteBONDING EQUIPMENT GROUNDING CONDUCTORS Bonding ensures electrical continuity to limit voltage potential between conductive ‘components. On the supply side (ahead of the main disconnect F16), it provi path back to the utility transformer for faults on service conductors and mits voltage potential to other systems, such as telephones or cable TV, On the load side (alter the main overcurrent protection F'18), bonding and equipment ground- ing provide a path to clear faults and protect against shocks. Bonding & Equipment Grounding Methods 17 NEC Use listed connectors, terminal bars, exothermic welding, machine screws engaging 2 threads or secured w/ nut, or thread-forming machine screws engaging 2 threads F11 250.84 1 No sheet metal or drywall screws F11 250.8A 1 Connections may not depend solely on solder 250.88 1 Clean nonconductive coatings from contact surfaces 250.12 MERGE 0 Grounding Methods Listed connec: tors OK (barre! crimps, wire » * Connect ail equipment grounding conneciors nuts, pushin connectors) screws NOT Tt i maintained if device Supply-Side Bonding F12,13,16 17 ne Cl Bond all service equipment, raceways & cable armor _ 250,02 El Threaded fittings OK for bonding service conduit 250.0282 Dl Meyers hub OK for bonding service ‘conduit F12, 250.9282 Do ‘Standard locknuts not OK on supply side of service FI2 250.9282 CD Bonding Jocknuts OK if no remaining ‘concentric knockouts F12 __ 9509284 y'd around impaired connections (concentric pars dma oop aos 8 __ 250008 1D Senice neutral can bond suoply-side easement a a 30 42a i eecterte pall Stern seo maimed bw, e service neutral & equipment grounde F16________ 250,241 me to the GES ___—_—— 260.106 1 Bond lighining protection PU ae) cam Fittings with No Remaining Concentric Knockouts e Bonding Jocknut e @2 Bonding at Impaired Connections _— Bonding jumpers Bonding bushing Intersystem Bonding F14 17 NEC 1D Separaie decodes for phone/CATV req #6 bond to power GES _800.100D 1 Accessible Intersystem Bonding Termination (IBT) devce req'd external to service equipment 1 [BT req'd at disconnecting means af separate buildings. 18 rea's min 3 terminals listed for grounding & bonding 1 IBT device not to interfere w/ enclosure cover: 250.9443 Cl Min #6 Cu to bond IBT to service or GEC. 200.94A485 LD GEC or nonfexible raceway OK &s bond point in existing buildings 250.94% BIBT not req'd if communications systems not likely to be used__ 250.94%'" 250.94A" 250.948 250.9442Load-Side Bonding 17 NEC (2 Bond any metal piping system capable of becoming energized, including hot & cold water &gasF14,15 980,104 CO Size water pipe bonding per TS a 250.104A1 O Size gas pipe bonding per T6. 250.1048 1 Gas bond may be from EGC of circuit Ikely to energize piping 260.1048, Bond metal well casings to EGC of pump motor __960.119M _ EQUIPMENT GROUNDING CONDUCTORS (EGCs) GCs limit voltage on enclosures and provide a path for fault current. Without GCs, the frame of an appliance could remain energized if there is a fault. ‘Equipment grounding provides a low-impedance path so the overcurrent device will open the circuit. The purpose an of equipment grounding system is completely ‘different than that of earth grounding; earth plays no part in helping clear faults. General 17 NEC (1 EGC must provide effective ground fault current path 250445 DD Earth is not an effective ground-fault current path 250.4A5, 0 Size EGCs per T6 260.1224 Gl Remove pant ‘rom contact surfaces of pipes for 250.12 field-installed equipment such as ground clamps. [ EGCs must run with other conductors of circuit EXC __ 250.118 & 300.28 * Replacement of nongrounding receptacles (see p.28) 250.1306 i Neutral not to be used for grounding equipment EXC. 250.1428 * Existing renges & dryers 250.142BX1 ‘Types & Identification of EGCs D1 Wrre £GCe can be bare, covered, or insulated 950118 1 Conductors < #6 must be bare or factory insulated w/ green (or green with yolow stripes) 950.119 Cl Conductors 2 #4 OK bare for entire exposed length ‘or use green tape or labels encircling the conductor 260.1194, Fl Green not OK for neutral or ungrounded conductors, 250.119 [OLRMG, IMC, EMT, AC cable armor, electrically continuous 250.118 raceways & surface metal raceways OK as EGC. FMC& LFMC not OK as EGC exc for non-motor circuits in combined lengths to 6 ft. with grounding fittings F 950.118 Pete he sik s ened Bresker or Fuss Bonding Interior us: Piping ng syste be b ing energized them at a gas water h provides an easy way What we commonly call an “electrical pane!” is referred to as a panelboard (NEC 408) inside a cabinet (NEC 312) F16. See p.# for working-space requirements, Clearances & Location 17NEC (1 OCPDs readily accessible & max height AFF 6 f. 7 in 240.248 No panels or OCPDs in clothes closet or bathroom 240.24D8E 1 No panels or OCPDs over steps of a stairway 240.24F Enclosures (Cabinets) 1 Enclosures weatherproof ( NEMA 3) in wet or damp locations 312.2 1 Surface-mounted wet or damp location metal enclosures min Vain. air gap between enclosure & wall 3122 1 Equipment rated for dry or damp locations must be protected against damage from weather during construction. 110.11 1 Open knockouts & twistouts durabiy filed EXC 110.128 + MFR holes such as these for mounting OK 110.124 1 Protect bus bars & other internal parts from contamination (paint or plaster) during construction 110.128 1 Max setback in noncombustible wall (steel studs) "in 3123 1 Flush (no setback allowed) in combustible (wood-frame) wall 3123 Cl Max plaster gap at side of flush-mount panel "/ain. 3124 D1 Dead:front cover req’ 408.38, 1D Circuit directories to distinguish each circuit trom all others: 4084 1 Directory labeling not based on transient conditions. 408.4 1D Unused (spare) breakers labeled 408.4 Equipment Grounding Conductors in Panels 1D Grounding terminal bar req'd if wire EGCs present F17 408.49 1D EGC not on neutral bar in subpansle, 250.2445 11 > 1 EGC (not neutrals) can be connected in 4 terminal if alowed by L&L of panel 110.144 & 408.40 1 EGCs & neutrals may not share same temninal, even in service 408.41 ‘equipment where they are allowed on same terminal bar Pe eo iSe WIRE BENDING SPACE JULTIWIRE CIRCUITS Barriers over Neutral Conductors 17 NEC Service 1 Bond neutral, EGCs & enclosure in service panels F16 250.246 Panel ee 1D Isolate neutrals in subpaneis F17 980.2408 ee 1 Gey mds nto depend n erlonree— 20028 Bonding fach neutral conductor req's individual terminel 401 ushing F13 El Wei iervid taro poe tarore cron o WGA pooan | read fr | SUPPLY SIDE no —aoer | Sites Loan SIDE * When grouping is obvious, such as a cable system 200.48X1" entering + When passing through a box with no loop or splice 200.48x2" through euitral conciactor 1D Neutrals factory-applied white or grey EXC. 200.6A concentric Wdoesitied (wets Simba et wince gees eit w_____rooo | noche Sicandees) (White not OK on ungrounded conductors EXC __ 200.7A ~“, * White conductors of a cable assembly OK as ungrounded 7 GEC ae conductors with tape (not white or green) encircling ends __ 200.7C ences OCcPDs Gl Bus req’s overcurrent protection on supply side EXC F16,17 408.36 Be erp * Service equisment bus w/>1 main disconnect. 408.38x1-3 Breaker oes 1 Breakers mus: be isted or classified AMI for panel _ 11038 protects Protect ungrounded conductors w/ OCPDs 111,15 240.4 panel & cama 1 2-pole breaker or 2 single-pole breakers w/ approved handle a aecasien ties req'd for multiwire circuits or for 240V circuits F17 _ 240.15B1&2 feeder 1 2-pole breaker or 2 single-pole breakers w/ approved handle ties req'd for receptacles on shared yoke. ___210.7 fam 1 Backfed breakers secured in place EXC__ 408.360 + Output circuits from listed utlty interactive PV inverter__705.12B5 Subpanel Panel Wiring 1 Torque all breakers & terminals AMI ___ «11038 & 110.14D" TD Antioxidant on Al conductors AM) 1102.14 — Dl Secure each cable entering pane! AMIF16,1749____ 312.80 hana Gener Wire Space single-handle 1D Avoid crowding of conductors = ___ 3127 2-pole breaker. 1 Spices taps in panole OK to 40% fi, 75% max cross-section. $12.8A182 Power-monitoring devices OK if fsted & meeting above fil eq's ___ 912.86 if more than one circuit in raceway 1 Feed-through conductors OK to pass through pane if warning on ens label that identifies power source is applied to enclosure 312.8A3 2 Sipe Sim Min bending space for conductors not entering or leaving See ‘wall opposite terminals (*L' bend) per T7A, F18 312.681 russ ao 2] Min bending space for conductors entering or leaving siuabece on aa ‘wall opposite terminals ("S" bend) per T7B, F18 EXC 312.682 Rac wire, Also applies cl to raceways with © TTA distance from terminal to wall OK if conductor enters . No wire tie Cow ‘or leaves in gutter & meets distance per T7A, F16. 312.6B2X1 teales be ore te 1 Conductors entering from back wall req T7A distance muttiwire circuit. 408,580" circuit in cable. to cover and T7B distance from terminals F18__— eenWire Bending Space (For clarity, neutrals & EGCs shown) Dimension T78 from panel wall to lug dotermines max conductor size. The conductors from this breaker are allowed T7A size because ‘they exit the side wiring space to en adjacent gutter that hes T7B— space. The adjacent gutter space is measured from the boundary posts above the main lugs. Conductors exiting wall opposite terminals limited to T7B size Conductors not exiting wall ‘opposite terminals limited to 7A: size Back-wall entry conductors. limited to T7A measured to front — panel edge 417B measuredto =f breaker terminal Pik nn Se eeaste cn a Pea a eta nse) L Bends—Wire not through wall TABLE7 'S Bends—Wire through wall opposite terminal CuWire Cuwie | AlWie' | Distance? aio | 128 wa 8 6 We 6 4 2 4 2 3 3 4 3 2 1/0 1 2/0 3/0 a0 6 250 on | so | 7 1. Compact wranded aluminum conductors using AA 6000 satis aon. Gree Tues ston angle, tw tance can ba moore wong henge Ww a th dwn ‘Tas tance i enaed in w raigh ro fom the gn ac on papendicl oho pal wak ae eta tS NELS Lit Multiwire Circuits 17 NEC Cl Ungrounded conductors must originate from opposite poles 400 1 All conductors must originate from same panel 210.48 1 Neutrals may not feed through devices whose removal would interrupt continuity (use pigtails from neutral to devices in box) 300,198 (All muttiwire circuits req handle ties or single handle breaker 210.48 1 All conductors of muttiwire circuit must be identified or grouped (wice ties or other means) inside enclosures EXCF17 _ 200.46 8 210,40" * Cable systems where grouping is obvious F17__ 200.481 * Where passing through box w/out splice or loop_ 200,48x2" Most utity raneformers for 1- and 2-famdy dweling services have two ungrounded “hot” conductors and neutral derived from the canter of the transformer, as depicted in F19. The neutral is connected to earth and isa "grounded" conductor. Te neutral mits the voltage on ether cf the hot conductors to 120V to ground. The service is a “3-wre” shared-neutal circuit. 120V branch circuits wih shared neutrals ae known as mutwire cicuts (iso called “Edison” circuit). tthe neutral ip broken of loose, voltages become erratic, az in F19 [ol TV seta, motors, end Computers don't do well wih fluctuating voltages: Signe of uetable valtage, eich as incandescent bulbs growing brighter or dimmer as ther loads change, could incicate a loose neutral either at abranch circuit rat the uty Multiwire Circuits Utility Transformer Secondary ~ yeaneu wedo EY PROPER CIRCUIT 2 unequal loads are fed by a S-wite circuit. The ‘neutral cartes the imbalance between the 2 loads El OVERLOADED NEUTRAL Without voltage potential between the hat conductors, the neutral caries the sum af the loads, In a 3-conduc tor NM cable, the black & red wires must originate from cifferent poles. [Fl OPEN NEUTRAL Tuo unequal loads in saries across 240V from the | anstormer, The load with lowest resistance sees the lower voltage. Voltage at each load depends on other loads and is unstable. 1. On 120/208 systems, the neutral aways caries currant, even in progeny balanced circuits, The principles here ail apply, ret TALE_ ARG-FAULT CIRCUIT INTERRUPTERS (AFCIs) AFCls provide fire protection by tripping when an arcing fault is detected. AFC! breakers and GFO! breakers look similar F21,24, and you must read the label to determine if oreeker is an AFCI or a GFCI. Dual-function breakers that provide both AFC! & GFCI protection are also avallable F21, Outlat branch circuit typo (OBC) AFCIe aro aloo available, including ones that are also GFCls, and the codes. have changed substantially to recognize these new methods The number of areas requiring AFCI protection expands in each code oycle. The time to plan for the AFCis is during the rough wiring, so that separate cables are provided for the crouits requiring AFC! protection. Not all brands and models of ‘AFCI are compatible with multiwire circuits, Beginning January 1, 2008, all AFCIs were req'd to meet the UL standard for “com- bination’ types rather than the older “branch/feeder” type. Combination AFCls pro vide @ broader range of protection then branchifeeder types. OBG AFCIs provide tho same range of protection as combination types, and when inotallod at the first outlet box on @ circuit protected by an older *branch/feeder” AFCI, that circuit then ‘complies with the 2014 and 2017 NEC. Areas Requiring AFCI Protection 17 NEC Cl Regla forall 120V 18A & 20A branch circuits supplying outlets or devieos in family rooms, dining rooms, ning rooms, parlors, lioraries, dans, bedrooms, sunrooms, recreation rooms, closets, allways, kitchens, lsundry areas & similar rooms EXC 210.1288 ‘May be omitted on individual circuit to a fre-alarm cirouit in RMC, MC, EMT, or steel-armored AC or MC cable w/ metal junction boxes that is, part of centralstation system in accordance w/ NEC Article 760 _ 210.12AX Ci Regis forall 120V 15A & 20A branch circuits supplying cutlets & devices in dormitory unit bedrooms, living rooms, hallways, closets, bathrooms & similar rooms 210.126 New Box & Receptacle on Extended Circuit — Existing Receptacle Replace with stocted OBC AFC! a! Unprotected being exter Replace with dual: function GFCI OFC AFC! wit foul 20 0.28). Replacement of Existing Ungrounded Receptacle New Box & AFCIs Labeled “AFCI" on face Two-Pole AFC! Outlet Branch Circuit Dual-function Breaker for (OBC) AFCI AFCI/GFC! Multiwire Circuits AFCI Protection Methods 47 NEC Cl Combination-type AFCI at origin of branch circuit ___ 210.1281 0 Branch/feedertype AFC! at origin of branch circuit & OBG type at frst outlet box on branch circuit, W/ outlet box marked as first on circuit 210.1242" 1 Ordinary circuit breaker at crigin of circuit & RMC, IMC, EMT, Type MC, or steeharmored AC cable to fist outlet, with OBC AFCI at frst outlet. 210.1285 C1 Ordinary cicuit breaker at origin of circuit & metalic or onmetalic conduit or tubing encased in min. 2 in. concrete to first cutlet & OBC AFCI at first outlet __ 210.1248 In-addivon to the 4 aiso inckides “supple protection breskers” & *syatem combination” OC! e used in cd Create 2 system that i listed. As of this writing, nest exiais, These two additional methc Extensions, Modifications & Replacements H ttwiring extended, modified, or replaced n areas where protection currently req’d, provide protection by ‘combination AFC! at origin of branch circuit or OBC ‘AFC! at frst outlet of existing branch circuit F20 EXC. 210120 “Not req'd when extension of conductors $6 ft & ddoos rot inchide ackied outlets or dovicos 210.1205 7 Ropiacoment receptacles in areas whare AFC! protection currently req'd must be OBC AFC! or be protected by combination AFC! or OBC AFCI EXC F20 406.404 + Replacomonts w/ GFCI receptacle in older 2wire systems where pane! does not accept AFCis & no practical means available to install EGC & no added wiring to receptacle & dual function AFCV/GFCI receptacles not available__ 406, 4004 1-4"‘GROUND-FAULT CIRCUIT INTERRUPTERS (GFCI. A properly functioning 120V circuit is balanced-the current that travels to the cutllet on the ungrounded conductor is balanced by the current retuming on the ‘neutral conductor. When a ground fault occurs, current travels on @ path that is not designed to carry current, such as the metal body of an appliance, or the human tbody touching that applianoo. This fault current creates a detectable imbalance in the appliance's circuit. GFCIs respond to these very low levels of current mba ance in @ circuit, and limit the duration of the fault to safe levels. ronically, even though the earth is not a good enough conductor to trip a breaker, it is a good enough conductor to carry the low levels of current that can cause electrocution. GFCis have substantially reduced the number ot electiocutions since they were first implemented. AFCle reduce fire hazards; GFCIs reduce electrocution hazards. in F22, 09) ats aro flowing to & trom the ated by the luc! posite polarity & the GFCI & the GFCI accounts for the ek he curre the GFO! @ other, The circu through a tions on each conductor. As lon, Resistor Circuit Balanced | load between hot & neutral utility | tanstormer During 2 fault F23 more current Hows to the foad than from the joad. This diterantal erestes a meget Fld tat induces vote coll. The resulting cu Coil signals the relay mechani irc n. whieh opens the Ground Fault Fault to enclosure Circuit opens when GFCI wnstream should dé. Labels ‘mt req'd for propery Locations Requiring GFCI NEC ‘See p.80 fot GFC} req’s for pool eg 1D GFOis req'd to be in reacly accessble locations _ 210.8 1 Distance measurements = shortest path wlout piercing Foor, wal, cxiling, xed berrier, doorway, or window 210.8 Grolpre Bathrooms Dl Garages & accessory buldings (po ception 1 Outdoors EXC “GFE cicit dadcaied to ron-eadiy accessible eceptacies for snow-eling or doing equpment 1 Crawl spaces at or below grace level 1D Unfinhed portons of basements or basement areas rat intended as habitable rooms EXC. ‘Permanent istaled cena station alarm ays 2 Whore eorvingltchen countertop surfaces F25 1 Within @ to a inks Within 6 af ub or showor tall FA 1 Laundry areas 1 Outlets supphing dishwashers 21080" 1 Hycromassage (whipoo tbs 80.71 odein GPCI have groaerresiaanee fo corrosion & surges, Thay a more fl Sra dcp oot evs tre peobler of Sikearen Dee Te © that sce onated for GFCis have boon removed rom the Te inlaaton nations foe OFC ate now sandacized le coneistaney oa iy nequre checking GPCI operation afer Malan fo ensure Pa : A ad ees on opera jon is req f & 204 210.901 210.8A2 210.843 210843X 210.8A4 210.8a5 2108AX 210.848 ‘210 BAT 210.840" 2108A10"PE eet MG Cantey (BRANGHeIRcUTSeouTieTs EN Branch cirouts are the permanent wiring between the final OCPDs (fuses oF broakers) and tho outlets that provide power to electical equipment. Separate Circuits are required forthe kitchen small applance circuits, bathroom receptacles, laundky, garage, central heating equipment, and large appliances. h some cas fas described below, these are “individual” ‘crcuts, with only one pleca ‘of equip tment on the sirout, With few excoptions, roquirad raceptace outlets must be eted tamperresistant types. Circuit Sizes, Number & Load Limitations 1D Rule of thumb: min 1 general-purpose circuit per 800 50, ft 22012 1D Load not to excoed rating af ranch ctcut. 22018 i Min size = 125% of contiruovs load + 100% of noncortincus load 210.198 1 Continuous toad = max current for $ hours er mor 100 1 Min size forbranch cireult wirng #14 Cu 210,10A4 1D Individual crcut = supplying only one piece of equipment 100 1 Branch circuit ratings for other than individual circuits must be 18A, 20, 30A, 40A, or BOA, G1 Single piece of coid-&-plug-connected equipment not permanently fastened in place max 80% of 15A or 20A branch crout Cl Max single cord-&:plug-ocnnected load on multireceptacle circuit rot to exceed 80%6 of receptacle rating 1 Lighte & receptacles OK on same 16A or 20A except small 17 NEC 21018 210.2801 210.2182 appliance circuits, bath-recoptacke circuit, laundy crout__ 210.93 Receptacies-General D1 Receptacles for specific spplances laundry, garage door opener) within 6 fof anplanes location __ D Flenble coms not OK as fixed or concealed wiring [Fl Receptacles must be mounted with 6-32 machine screws — Receptacle Types and Ratings 210.506 400.12 1065" TD Alrocoptasios on 154 £204 circuite grounding type 4084A 1D Receptacies for direct Al conrecton marked ‘CO/ALR_ 40630 17 Receptacles req'd by 21052 fisted TRtype EXC 408.12 + Receptades lcated’> 51/2. above for. 406121 1 Replacement receptacles listed TR type EXC — 400.405 ‘Replacement nongrounding type reseptaces eee p28) 408.405 184 20A nonlockng receptacles in damp or wet ean ated weather! om 4080481 1 Sl eceptacios aed nat shan bench erat 212181 ‘An eraple wourd bea single (rot dupe foe'a microwave oven range hood wit) a cord & plug c Tl Mutiple receptacles on branch crcut per TB__ 20218 errr of hese ulna duplex epic 2 eagles ot "ge reap peer une ui Bee Perret meee ‘Circuit Rating, ‘Circuit Rating | Receptacle Rati 75h 0A) 40 0% 50A 208, OA ‘0A, 308 Foyer Wail 32 Receptacle Spacing TV outlet> Bt AFF dovs nat count ‘a rey'd receptacle. Max 12 between wall ‘ceptacios mansired at Aooe/wall ne When wal placement possible dur fo glass to floor install oar receptacle within 78 in of wal Bar-ype counters are considered wall space and a receplace ts 129° 09 —~ the wall wihin Git of the ond. This receptacte serves 7 peninasle countertop. Ttcanrot court as @ wal space outlet. Hallway 240" chen \ Retigerator can be ‘00 indvidual creat an S Fh man Tat max amar ai morReceptacle Outlet Locations F25,26 17 NEC TT Walle > 2. wide r0q receptacle in habitable rooms _ 210822 1 Patitions& barype counters count as walls 108942 1 Dcorwaye, fireplaces & cabinets w/out counters rot wall 210.82A2" 1H Receptacles req go no wall space > 6 ft rom receptacle measured herizontaly along floor line of wall 21052A1 1D Receptacle req'd for hallways 2 10 fin length 210.59H 5 Receptacles that ae part of eloctri baseboard heaters (OK 8s req'd outiets-may rot be on heater orcuit _ 210.82 1 Receptacles> 5%, above foor do not count as reqld oulleta 210.62 {1 Floor receptacles > 1@ in, from wall do rot count as req'd outlets 2105243 1D Switched receptacles installed a req'd ghiing do not count as part of req'd receptacle outlets unless “half hot 210.82 210.521 10.52/" 1 Req} each wall2 3 tin foyers > 60 9q, ft. EXC__ * Sidelite windows to floor de not count as wall space 6 ft./12 ft. Rule and 2 ft./4-ft. Rule Wall receptacies serve the spaces 6 ft 10 each side of the receptacle. Therelore, the max distance of wal ne betwee receptacles is12 It Kitchen countertop receptacles serve tho area ior 2 ft. to each side, and max distance between receptacles is 4 6 wall | | QF 28 countertop 12 ft. max. wall,4 ft. max kitchen countertop een eT eee | FiG.27 | jand Countertops {sland countertops that are flat across the top require only ove receptacle for ountertop space. The receptacle can be on the side of the cabinet no move than 12 in, from the countertop surface if the overhang of the counter {op does not exceed 6 6 ft wall 2h countertop =n Island Range or Sink WX<12 in, the countertops ere ‘considerod separate space ‘and each roquites a roceptacte {At east two 20A srallappliance branch circuits are req’d in kitchens and dining areas. These circuit are in addition to thove for lighting or permanently installed appliances. Additional circuite can be installed for spacifc appliances, such a5 roltgerators. Receptacles are req for countertop spaces? ft. or more in widlh See p.14 for tules on AFCis & p.18 for rules on GPCI Branch Circuits Dl Min 2.208 smaltappliance circuits req'd 1 Smaltappliance cicults must serve al countertop & exposed wall receptacies in kitchen, dining room, pantry & similar arees EXC__ 210.5281 + Switched receptacles (dining room ight) _ 2105281X1 + 18A.cor 204 individual branch circuits fer spectic appliances 210.5981 x2" 1D No other outlets (including lights) on smallappliance circuits EXC 210.5282 17 NEC 210.1161 + Receptacles for clock or gas range ignition OK _ 210.8282X CD Dishwasher & disposer req separate circuits if combined rating exceeds branch circuit rating 210.1941 1 40A 240V circuits OK for range receptacle outlets 2102184 (140A or SDA 240V circuits OK for builtin cooking applances __ 210.28 Receptacles for Countertops & Work Surfaces D Reoeptacios reid forall wall counter spaces 212. wide 210.5261 C1 No point along wal ine > 26 in. horizontally from receptacle F25_ 210.5201 1D Countertop spaces separated by angetops, raigerators, Corcinks considered separate countertop spaces F25______-210.5204 1D Area behind sink or range considered countertop space 2 12in.to wallor2 18 in, tocomer F29 _210.5201X (Max 20 in. above countertop 2105205 Dl Mult-outlst assemby in bottom of upper cabinet OK as req'd receptacles ifS 20 in. above countertop __2108208 1D Peninsulas req receptacte # long dimension 2241, & short dimension2 12m 2t0.52c3) 1 Peninaulee moagured from comectad perpendicular wall F25 __210.5209% 1D Each island countertop space w/ 2 24 in. long cimension & 12 in, short dimension req’s receptacle F27.28 1D Sink or range with < 12 in, behind divides sand or peninsula ‘countertops into separate countertop spaces _-210.5204 1D Receptacles OK § 12 in, below top of flat islands & peninsulas Where overhanging counter 5 6 in, past support base F27__210.5205 Ne face-up countertop receptacles 408.56 1D Listes pop-up receptacte assembles OK F27 210.5205 4 408.5E 1D Counter recentacies do not count as wall space recepiacles F25 210.52A4 2105262 x 50 Ib. rq independent support ‘314.2702 1D Palle tans req LAL paddle fan Dox ‘31827 1D Coitng-mountod bone w/ epare soparaiay switched ungrounded conductors eq listing for pad fan 14a L Sticke & CO slams OK to suppor on cevice ome 314270% Devien Secu nee ctor Support urate ie © 2 eunina holes ox cesMax. plaster gap Yan. Conductor Length wNec [i 1 Min 6 fn, conductor brought into box Fas == 300.14 (OO Min in. tree conductor past face of box FA5, 300.14 Box Fill 1 Size must bo sulficient to provide free space for conductor ion ____ state Standard metal bores per 19 314.1841 wecee {Include volume of marked rrud ings & extensions 314.164 scien 5 Spacon within boxes with bares counted separate 4.508 Overing et 1 Barrier volume as markod oF Yscu, in. metal boxes, tin. plaatia 914.1 0A" too large Improper Box Install: (I Plastic bores are marked w! their volume — 314.1942 Bor 1 4in (6 cuin) parcale OK only end of 14/2 run FA 314.168 Max. setback Vin. if ssarcer 11 1Bou.in,boxtoo smal for 3122 Romex 10, F31 314.168 noncombustible surface, (oot ing) | 2210 combustible Box Fill Factors 79,10 arNEC | Size (AWG) and Box Trade Cuin 1 Count each conductor exting box EXC. 314.1681 Sia | SHOOTS | sclime een ee + EGCs from luminaires o° up to 4 conductors < #14 6s | 10] 2] «| {ror luminaires with domed canopies 314,1881x 4x1 | Roundoctagona | 125 | 2 [5 | 5] 8/6 1 Untroken conductors passing through box count 4x 1% | Round/octagonal | 185 | 9 | 5 | 6 as only | conductor EXC ____________3144684 = ete $ * Looped urbroken conductors > 121m. eaunt 82 314.1681 4x2% | Roundioctagonal | 215 | 4 [7 | & | @ | 10] — D1 Donor count pgtaled conductors to devices 314.1681 1 Intemal clamps count only 1, based on largest conductor h bor _ 314.1082 41% saa 380i) 8 |S a)e7 |e ane Cl Support fitngs (tude or hickaye) count as 1 conductor for auth Square ao [4«[7]e|e| 1 ‘ach fiting type based on largest conductorin bor ___ 94.168 1 Count devices as 2 conductors based on connected wire size 314.1684 4x2ik Square aos | 6 [10] 12] 13 | 15 | Al EGCs count ony as 1 based on largest 4Mh0x 1% Square a6 [5 |e [iol | Scr atthe 14 ‘Square ws [s | oli fsal a] [tem wenn ‘Square 420 | 6 [14 | ie | ve | a | [Wiscontuctor oitng box #12 conductors exting bax Device! ze: [Saleen eanie es _ #0 conductors eating box Bx9x9 Device! ROU MCM IERIE) | 40 conductors extn box ae Device! ws t2lala|a«ls Wicninew eligi 7 Poe Deve Tae | Saleulneal eae Largest grounding conducior-count only one 1 Devices: 2x connected conductor ze 9x2%2% Device seo) | 4 |S) |e: | (ena clampe-one based on largest wire present 1 Bx2xo% Daves! [480 [9 | 6 | 2] ©) © | | Finuettnge-one tor each Ope Based on krgoal GE 4x2texi%s | Device! ws [2isialalo TOTAL re “Gx2inxiih| —_Devico! wolfe l*ls|s]¢| mio — >= axainxain| Device! 5 [2]4[s5 || 7 unde ah | Masonry boveerg | 140 | 2 | 4 | 5 | 6 | 7 Pancake axa | Masonrydovoany | 210 | 4 | 7 | 2 | 9 | 10 re [FS | Sriplecoverigang | 196 | 2 | 4 | 6 | 6 | © 7 sivdaniaen FD | Sngecovergag | 160 | s |e | 7 | 0 | 0 ten, yore feu'in voume ae aCe 6 bar can be used at tha anc fu Of 14/2 NMC abe nein the bow, Ciheruien, paneahe Boker eat be ; 4|alo hauing a red canopy wth te whame a ihclnt and 2 marke yh muna aLIGHTING SWITCHES APPLIANCES PLC tC) Lighting outlets and luminaires mast be installed with no exposed lve parts that pose a shock hazard. Lights rated *type IC” are suitable for insulated cotings, General qWNEC 1 Alltuminaires, lampholdors & retrofit kits sted 4108 1 Exposed metal parts grounciod EXC 41042 + Incidental metal parts such as mounting screws 410.42 1 Wet location luminaires LAL for wet lacation —_ — 410.104 1B Damp locaton luminaires L&L for damp or wet lation —_ 410.108 i Screw shels for lanpholders only-no adapters 410.90 Recessed Lights 1D Nor-Type 1C min Via in rem combustibles 410.118A1 D1 Non-Type IC min Sin, from insulation —_ 410.1168 1B ype IC OK in contact with combustsie material 410.1182, 1D ype ICO in contact with inaultion 410.1108 1B Luiminaires that req > 60°C wire must be marked 410.74 Connect proper temprated wir to luminaire FS 410.1178 1D Tap conductors per NEC 210.19A4X1 (#14 on 20A ret) OKit complying with note at bottom of F35. _ 410.1176 Recessed Lighting with Old Wiring New high- temp wire Ord low. wy SOV must be sted __ ey 422.108 1D Branch crcut rating rating of appiance. 1B Branch circu rating 1259 of rating of applance Wf cordinuousload 422.104 Contral Heating Systom 1D Ovta heing eure ial cout EXC 12219 “Fated eqn soved Gas par, hin os) AR Xt ‘Pamaren) comeced AC eminent aan 1902 Cl mgctconnet ea Mocha Caen 8422 310-6 Pua ter hevundese ur posdBR vphiancral GGPO reteoana Pl TS Ushio oto cdo apace wt po ony i onnce 212.7048 £7 1207 rsplace ode 20 ovale 21063 RM sso" MEG su" switcn aor fused switch An exam | 208 creut lL Water Heater (WH) [D Coneideres cominuous load fr sting circus (size at 12596) _42213 Cl tn-tight disconnect or lockable breaker or ewiteh reqiF39, 4218 1 Bond tot, cold & cas pines FS. 250.104 D Instantaneous WH w/> 1 crcll must have disconnects 42230 (grouped & identitied as the WH dacornecting means Air-Conditioning 1D All outdoor conduits in wet locations must eartain wet-rated conductore~no NM able [1 Wring & OCPD per nemeplate of LAL equpmant 3009 & 810,106 (OCPD ussal larger than number shown in T18) “4048 1D Discornect on or within sight of cendencer Fa 44014 1D Discornact not OK on compressor access panel 4044 5 Working space rec'd infront of disconect F2 710.268 Bi Room AC reqs EGC _ 44081 440.620 D Room AC max ating G09 of dll branch circuit ating — Room AC core & pag OK as ony diacannectitcontrole $6. of foor_ 44069, [Di Mex cord lngh 120V= 10 R, 240V=6 1 44084 EAPC or leakage current detecion interrupter LCDI in 44085 Air-Conditioning Condenser . | Conductors in, outdoor raceways must be sult ibe for wet locations “ho NM cable Switch not to ie installed recy behind AUACS quire 9“ condenser rah Central Vacuum 17 NEC Ti Max 80% nalvidual branch circuit rating, 50% of ‘mutate branch ciruit rating. 422154 8210238 1D Cord eepacity > branch direut eonducter ampacty 409158 5 Bond nomcurent-canying metal parts to EGC 42218C Electric Furnaces & Space Heaters D Considered centinuoua load for siting circuit (sive at 12546) _ 424.98 1D Disconnect in sight orlockable breaker or switch F39 424.19 1D Unit switch that opens all ungrounded conductors OK a 494.106 dzcormoct for apace heater with ro moter> Ye ho Hydromassage Tub (Whirlpool Bathtub) (D Individual branch rout reed em D Ready accoasbla GFCI protection ef 880.71 D Allroceptacten within 6 ft. eq GFCI protedion F#9 680.71 D Electrical equipment (pump motor) must be accessibe 980.73 1D Cer & plug connection receptacle mas 12in. tom hatch eporing & receptacle face in view Fa__80.74 Bend metal piping. surfaces, rcaways, cables, motors & electical devices Within 5 fof tub & metal pats that contact circulating water P43 _680.74A Banding condictor min said #8 Ou FAB. 600.4 1D Gennect bonding conductor to mato ug EXC FA 680.748 + Doubie-reulated motor (natal bond wire for future) a0 744x2 680.45 1 Bonding conductor need rot connect i panelboards. #8 conductor bonded to moto: lg Intended for bonding = Cord and plug receptacle for motor placed in rect view through eecess: Bond to meta piping ‘systems & any grounded metal paris in contact ‘pening & <12 in. tom opening smn creating waar Built-in Kitchen Appliances: 17NEC 7 Pala corde (not NM cable) OK for applies ‘conte lst} for fenble cord connection 402,184 422.1681 C) Garbage disposer cords OK min 18 in, mat 96, [5 Compactor corde 94 Ri, teamited fn back of ape 42} ae) 17) Compactorreceptacis in aoplance space or adacent spice 422 18B9(8) [51 DW cords 3-85 measured from back a appliance 422 8B) [L1DW recaptacie upace adjacent tocishwasher 422. 1563(6)" 3 Range hoode cord peg OK i UB for cont prteciod Fam physica damage & on vidual beach sreut 422.1684 I Range hood coe in 18 mx 48 72 ea 1 Groundog ype pga fo: appharces above ER aaa 222188 + Lted double-nauated appliances C1 Cord pig overs & cooking unta OKWLSL 490.4883 Cn An ADD DDD LEER‘WIRE AMPACITY To determine the comec! wir wee for a given OCPO (kise or broaker), factors such ax the temperature rating of insulation, ambient temperature, proximity to other conductors, and function ofthe circuit must all be considored se the appropn must be sppled to the empscitylatic in 7 fe coluran THY forthe ype of wie beng used 722. ee aren Lay General 17NEC ribtaet Torres > SONG (i 1 Prec conductor at her ampaiy EXC 1404 | ambient | kecasaets Sorts he Res ee oe + Bia ecodioors protected per ote A a TH aoa | tompee Temp * AC protected AML motors per article 420 240.46 soe 78°C bec {2 When anpacy boven 2 stared re OCPD OK owe as | ont oor ace | ares rentanger OOPD nat branch eeu w/t ecb 24048 C. Protect per lowest rated device, terminal, oF wire in citouit. 110.140 3-40 082 088 ost 96-104 Use 6% colin oreandicores #1 rs 100 amps THY 11040) | ayaag } a ae ae GbeckG ates ec dccrssiosicoeeat Nee, D. Use 90°C column only for derating conductors rated 90°C T1113 110.140 46-80, 088 0% oe2 Teta 1 Serioe conductor alowed tobe 89% of 11 ampaciy 714. 9101889 | gage] oar a RS Derating Apply temperature correction factor T12. _ 910.1582 58-60 = O38 OF 432-140 Ada 30°C w 112 fr cond or cables “Toi abow woe _—aiotsBa" | gicag TS ca? oss | 141-140 bes osunetter ie eines None oe grouped without spacing > 24 in. in length T13, 910.1538 68-70 ez bd = Se 1 Neural cont x curer-camin cndaton for TIS EX 1018898 [tte empress TO po + Neutral of mutwire crcuit or feeder rom 120/240V system 31015836 © Donte>2 NM eae cnet Grbced fl aed perenn watt spacing coin wh hr on 13 23180 1 Une 80% for dering NM caio;bave OCPD en 6S anpacy—ean.e0 | Number of Cron Canna Wes “8 c : 5 Zz we [rc | we [aoe | we | we oe oe hie 6 wal omen a nays tng ees a SecP | ieee Uienr:|cager | a9 | cunt camyrg conductors aed stl be within the some the ames aie T2S. Taw | THN , | Sees co | mw | Taw rw | xan | uses, cain) UF | raw | THM2 | TE | ME / tat jaa! [ating | uWire Use | Tan? Chimps | size(AWeo | size ae | Amps) rr a wis |] = |. - | | ws [2 | 10 = |= | = ps [=] = fae woop fe oko | Booked sw | | = | « 20] a5 | 1 | [A Suede toctarmscayn rps Late le i |B 2014 NEG metnctedto LIOCMOV wyateme, also atoms 1 BOrRO8N.S* s a 0 #. # cs & s C Tha table i allowed lex service conductors + main pow feediar that camry the weing ‘[e[«| [of |= |e Hibuetanch oan rang eyes ae RE ees woo | 1 | we | : +1 rts iD re Wire Size AWG) | ruse of | Wire Size (awa), ae rect 10 130 14 05 100 116 + Brooker cu at reaine: AL ¥ 32 2 “o 0 300 380. “00ron DLE aa oat Cd ETL t Ly UF Cable == UF unable for cry lamp, cor wet locations; NAT is ony ‘rtable fr dy cations. (Cable systems ar the most common residential wring methoda. Cables contain ee al conductors of the circuit nside a protect cuter swath of retl or plastic, Cable Protection indoors (NM, UF, AC, MC, SE) 17 NEC 1 Bored holes for cable min 114 in. setback from lace framing mombors or protect w/ steel plate Fad 1 Protect cables in notches wi 1 in. tee pate ©) Cables parate to framing members req min. 1% in, eolback from eurtace FAS: 00.441 —— 900.449 30040 Cable Stacker Cables cannot he placed side by si Ere ee ‘raming, Underfloor Cable in Basement or Crawl Space Nail-Piate Protection S-conductortg Deondhctortg cables <1 In A lited onbie tucker Solves the problem bunds of cat bbe within 12 in of Steel plate min. rein ‘thick Clam suitable for NM or MC Nt cable connector MC cable clams, | (no locknut style) of conductors Into box, rin. 3 in. past ‘ace of Box NM-Nonmetalic Sheathed Cable F47 Nec rag rami endcocio af ot OOPD Tok ny can 5 free ea tom sca dager aces ee ragae pote ta hes woh rt an i oe mon w/nMrated cy 48 og 5 Seow beige an) pate box OK wl cao eal only-net allowed in caro wet locations __ 994.1204 00.401 som 14,170) reesei in of torr Ua sahig ino box —_—__ 8141708 Cl tats atoning ne bos past ee of inp. 2 condictor T21 EXC “224 Gupr 6TH + Stmight cond $24. OK to have 6D9G 8 Ghaoer@T1 note 4 [2 Dente conactr in aoordance with 12,1, 21015028 { Corduciore2 #8 must be standed EXC ‘810.1066 “GEC bonding conductors (9.8 &p.10) woldOK 25062 RIGIEEN FMC-Fiexible Metal Conduit 1 tor of a uncegaund races a wet bcaton 30088 ier a a atv rac rcownye we lsatione iva vt neater _ 800.9 Coes { Wetrated conductors cables tin wet baton acenays 310.106 | Factory coer of ungounded conductors cacnot bo white or reer 310.1 10C [ Facory col of uta conducts wit, Ce ger EXC 310,110R48 + Conductor 2 #4 reidetfed et tominstions 81010888 *EGCecanbe baat 1108 2 Beret o have ove rain nis Mer 360" bende between pull pots Fs Lemc-tiquiatight _LFNC-Liawietight Flexible {Racoway mast bo reamed smoah ater ating Flexible Metal Condue —-‘Nonmetalic Condult 1 Cordis in racowaye re acy runded insatng busing wereentngendoeves PuCiacket —Comecor 1 Bow & conduit bd covers must remain accesaita ae i Racawaya not OK te suppot other eables EXC. + Ausocatod costal wing (2g, themostat to AG) i Metal racewaye & cabo sheathing net OK pass bores \ [Splicing in concut hocks any Hauler vlime permaking —a14 1802 | Cutends of meta itbon mist be trimmed Too Many Bends ‘taka? connacton FMC-Flenible Metal Conduit 3) aTNEC {Not OKin wet locations or subject toconosion or damage 34812 1 Suppor spacing max 4/2. tenal & 12m, rm bores EXS__—_948,.904 Inset pall point such se acondul body Total bends + Wheto needed: 38 n. O 6H woatedevny3_—___—__ gm {Bore amoeth-conot rece inn —REb20A C1 Secug win 12 nd etoapt uplo SOK hese 9580. {Be ct nd o removed rough 08908 9S) cone ang connect ExPomited s EGC EXC wom DEGCredt “+ EMT on root serving AC equipn ay gy \ \ YVR VV VO17NEC — PVC-Rigid Polyvinyl Chloride Conduit F58 7NEC 1 Cover above buted conduits par 1 300.54 tring mod hat allows RMC-Rigid Metal Conduit F57 {Galvanized RMC OK for drwct burial or embbedment w/ approved eorroaion potection 944.1081 Ol Support por T17 with D1 Where exposed to meisture,feld cut Fe threads req LAL compound 900.64 ovement from themal expansien & contraction 982.00 1D Provieo bushing er fiting at box connction F87 344.48 (7 Horizontal run supported by holes in faming OX if securaly loss connectors not OK on threaded condut ends 944.49 faatened within 3. of box, condi tody, or cabinat 352908 — 98248 Othe Z Seoure in place within 3 f. of termi 7 Bushings or adaptors req'd to provent wre abrasion, nEXC. 34401 1 Smoothly rounded insulating bushings req'd or conductors 2 #4 3004G, = LOK where suc members proven ‘siening win 844.9082 1 Horizontal ure aupportod by hale in raning OK ecarly Expansion toga rog if alc 7 mevamen T20 — 0240 fastened within Sf ob, cond body oF cabinet 344308 Not OK fr wppat fines or bax 382198 {Horna suppor sping w/ headed ceuplngs 17 344.9082 Not parted in envionment > 50% (12277) 362120 : i 8 DISTANCE AT WHICH PVC CONDUIT REG Moved) etna dablecd EUMMMCUTCECNEEM Pucttene) cance | ects) Datace | uerters] 0 IMC/RMCSize | Max Spacing | PYCSze | MaxSpacing | | Chanae'F|_t-m) | Ghorge’™*| facia) | Change] _(e-h) awn [08 inet 3h 4o_| 15-5 [oo [7-9 [00 [eee tin 12 5h e-10 | 190 | 4-9 (wetweae mn wo [tase I 2v 168 7h | a. 5 | a aoe Peo rani Conduit Fill Examples ses ane rare) [i [sar 163 mee condo tobe 40% of az [sox [ews [ores [ins ae 2 or =] thoconait ren yi as 10 oma] = Acieuithas 9 #2 conductors [_%_[asaajoate]axzr]aras [osas atar| ass [ss ‘casse | eus | 1 #8 EGC, all with THEN inoula: ‘% [ears [oase|eara] cave [oars [aaa] oaa0| area [aoa] 0807 toe Re, Rat ae 720 Shania 298 + [o34e|03x3[0:227] 034s |a3e2/0.84] 038s] 0.278 [asa] cor | ee yee TeHneo11504q n, |_iltlfosseltsei ast enim antes onro) oes)one) = Fostis gettin cossoreain, [1 [0sta|a7s4]a7es) o7e2 [ase [asso] 079) anes axed ssa svorsecoaer con, | 8) tawal eel soe ane eer tase) aon reo ie ci —| 1 x0.0s07 00807 aan | 24 [2sea] — [rges] waa] — [asd tesa) x57 ar he Total min wea = 0.9981 99, 3 [ssse[ - [2ez7)200/ - [3160/3000] 2577] 2007] yania | Fon 72%, thenot lager sce tx PvCA0 | ata [ate] — [aa4a/aana| — |4a04)4ane| ans a [nari] 20581 25.0, terre tein const (fsa) arm | faa ta aac neal 23421] or G0 np copys eee nT 18 sale — | — [oss 422504 ae Teac iat dat a Pee cd | Sit | es | ccitina| fer | ckvawwa | GRO _| pene ie a Fete pete a a I = er é vows | Somer