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0 kVA plus 40 percent of the remainder of the following loads: * (1) 33 volt-amperes/m2 or 3 volt-amperes/ft2 for general lighting and general-use receptacles. The floor area for each floor shall be calculated from the outside dimensions of the dwelling unit. The calculated floor area shall not incl...

0 kVA plus 40 percent of the remainder of the following loads: * (1) 33 volt-amperes/m2 or 3 volt-amperes/ft2 for general lighting and general-use receptacles. The floor area for each floor shall be calculated from the outside dimensions of the dwelling unit. The calculated floor area shall not include open porches, garages, or unused or unfinished spaces not adaptable for future use. * (2) 1500 volt-amperes for each 2-wire, 20-ampere small-appliance branch circuit and each laundry branch circuit covered in 210.11(C)(1) and (C)(2). * (3) The nameplate rating of the following: o a. All appliances that are fastened in place, permanently connected, or located to be on a specific circuit o b. Ranges, wall-mounted ovens, counter-mounted cooking units o c. Clothes dryers that are not connected to the laundry branch circuit specified in 220.82(B)(2) o d. Water heaters * (4) The nameplate ampere or kVA rating of all permanently connected motors not included in 220.82(B)(3). (C) Heating and Air-Conditioning Load. The largest of the following six selections (load in kVA) shall be included: * (1) 100 percent of the nameplate rating(s) of the air conditioning and cooling. * (2) 100 percent of the nameplate rating(s) of the heat pump when the heat pump is used without any supplemental electric heating. * (3) 100 percent of the nameplate rating(s) of the heat pump compressor and 65 percent of the supplemental electric heating for central electric space-heating systems. If the heat pump compressor is prevented from operating at the same time as the supplementary heat, it does not need to be added to the supplementary heat for the total central space heating load. * (4) 65 percent of the nameplate rating(s) of electric space heating if less than four separately controlled units. * (5) 40 percent of the nameplate rating(s) of electric space heating if four or more separately controlled units. * (6) 100 percent of the nameplate ratings of electric thermal storage and other heating systems where the usual load is expected to be continuous at the full nameplate value. Systems qualifying under this selection shall not be calculated under any other selection in 220.82(C). ENHANCED CONTENT Collapse Section 220.82(C) requires that only the largest of the six choices needs to be included in the feeder or service calculation. For examples of calculations using air conditioning and heating, see Examples D2(a), D2(b), and D2(c) in Informative Annex D. 220.83 Existing Dwelling Unit. This section shall be permitted to be used to determine if the existing service or feeder is of sufficient capacity to serve additional loads. Where the dwelling unit is served by a 120/240-volt or 208Y/120-volt, 3-wire service or feeder, calculating the total load in accordance with 220.83(A) or (B) shall be permitted. (A) Where Additional Air-Conditioning Equipment or Electric Space-Heating Equipment Is Not to Be Installed. The percentages listed in Table 220.83(A) shall be used for existing and additional new loads. Table 220.83(A) Without Additional Air-Conditioning or Electric Space-Heating Equipment Load (kVA) Percent of Load First 8 kVA of load at 100 Remainder of load at 40 Load calculations shall include the following: * (1) General lighting and general-use receptacles at 33 volt-amperes/m2 or 3 volt-amperes/ft2 as determined by 220.42 * (2) 1500 volt-amperes for each 2-wire, 20-ampere small-appliance branch circuit and each laundry branch circuit covered in 210.11(C)(1) and (C)(2) * (3) The nameplate rating of the following: o a. All appliances that are fastened in place, permanently connected, or located to be on a specific circuit o b. Ranges, wall-mounted ovens, counter-mounted cooking units o c. Clothes dryers that are not connected to the laundry branch circuit specified in item (2) o d. Water heaters ENHANCED CONTENT Collapse Where Additional Air-Conditioning Equipment or Electric Space-Heating Equipment Is to Be Installed. The percentages listed in Table 220.83(B) shall be used for existing and additional new loads. The larger connected load of air conditioning or space heating, but not both, shall be used. Table 220.83(B) With Additional Air-Conditioning or Electric Space-Heating Equipment Load Percent of Load Air-conditioning equipment 100 Central electric space heating 100 Less than four separately controlled space-heating units 100 First 8 kVA of all other loads 100 Remainder of all other loads 40 Other loads shall include the following: General lighting and general-use receptacles at 33 volt-amperes/m2 or 3 volt-amperes/ft2 as determined by 220.42 1500 volt-amperes for each 2-wire, 20-ampere small-appliance branch circuit and each laundry branch circuit covered in 210.11(C)(1) and (C)(2) The nameplate rating of the following: o a. All appliances that are fastened in place, permanently connected, or located to be on a specific circuit o b. Ranges, wall-mounted ovens, counter-mounted cooking units o c. Clothes dryers that are not connected to the laundry branch circuit specified in item (2) o d. Water heaters ENHANCED CONTENT Collapse 220.84 Multifamily Dwelling. (A) Feeder or Service Load. It shall be permissible to calculate the load of a feeder or service that supplies three or more dwelling units of a multifamily dwelling in accordance with Table 220.84(B) instead of Part III of this article if all the following conditions are met: * (1) No dwelling unit is supplied by more than one feeder. * (2) Each dwelling unit is equipped with electric cooking equipment. Exception: When the calculated load for multifamily dwellings without electric cooking in Part III of this article exceeds that calculated under Part IV for the identical load plus electric cooking (based on 8 kW per unit), the lesser of the two loads shall be permitted to be used. * (3) Each dwelling unit is equipped with either electric space heating or air conditioning, or both. Feeders and service conductors whose calculated load is determined by this optional calculation shall be permitted to have the neutral load determined by 220.61. (B) House Loads. House loads shall be calculated in accordance with Part III of this article and shall be in addition to the dwelling unit loads calculated in accordance with Table 220.84(B). Table 220.84(B) Optional Calculations - Demand Factors for Three or More Multifamily Dwelling Units Number of Dwelling Units Demand Factor (%) 3-5 45 6-7 44 8-10 43 11 42 12-13 41 14-15 40 16-17 39 18-20 38 21 37 22-23 36 24-25 35 26-27 34 28-30 33 31 32 32-33 31 34-36 30 37-38 29 39-42 28 43-45 27 46-50 26 51-55 25 56-61 24 62 and over 23 (C) Calculated Loads. The calculated load to which the demand factors of Table 220.84(B) apply shall include the following: * (1) 33 volt-amperes/m2 or 3 volt-amperes/ft2 for general lighting and general-use receptacles * (2) 1500 volt-amperes for each 2-wire, 20-ampere small-appliance branch circuit and each laundry branch circuit covered in 210.11(C)(1) and (C)(2) * (3) The nameplate rating of the following: o a. All appliances that are fastened in place, permanently connected, or located to be on a specific circuit o b. Ranges, wall-mounted ovens, counter-mounted cooking units o c. Clothes dryers that are not connected to the laundry branch circuit specified in item (2) o d. Water heaters * (4) The nameplate ampere or kVA rating of all permanently connected motors not included in item (3) * (5) The larger of the air-conditioning load or the fixed electric space-heating load 220.85 Two Dwelling Units. Where two dwelling units are supplied by a single feeder or service and the calculated load under Part III of this article exceeds that for three identical units calculated under 220.84, the lesser of the two loads shall be permitted to be used. 220.86 Schools. The calculation of a feeder or service load for schools shall be permitted in accordance with Table 220.86 in lieu of Part III of this article where equipped with electric space heating, air conditioning, or both. The connected load to which the demand factors of Table 220.86 apply shall include all of the interior and exterior lighting, power, water heating, cooking, other loads, and the larger of the air-conditioning load or space-heating load within the building or structure. Feeders and service conductors whose calculated load is determined by this optional calculation shall be permitted to have the neutral load determined by 220.61. Where the building or structure load is calculated by this optional method, feeders within the building or structure shall have ampacity as permitted in Part III of this article; however, the ampacity of an individual feeder shall not be required to be larger than the ampacity for the entire building. This section shall not apply to portable classroom buildings. Table 220.86 Optional Method - Demand Factors for Feeders and Service Conductors for Schools Connected Load Demand Factor (%) Calculated Loads (VA) Total VA/m2 Total VA/ft2 0-33 0-3 100 Amount x 100% Over 33-220 Over 3-20 75 (Amount x 75%) + 3 Remainder over 220 Remainder over 20 25 (Amount x 25%) + 15.75 ENHANCED CONTENT Collapse The air-conditioning load in portable classrooms must comply with Article 440, and the lighting load must be considered continuous. The demand factors in Table 220.86 do not apply to portable classrooms, because those demand factors would decrease the feeder or service size to below that required for the connected continuous load. Table 220.86 provides a series of demand increments that are permitted to be applied to the initial calculated load for service or feeder conductors supplying the total load of a school building in lieu of the “standard calculation” covered in Part III of Article 220. The incremental steps of Table 220.86 are based on more significant reductions of the total load as the load per square foot increases. Any portion of the load exceeding 20 voltamperes per square foot is permitted to have a 25-percent demand factor applied. This approach is similar in concept to that applied to dwellings in Table 220.45, except that the demands in Table 220.86 apply to the entire load of the building, not just the general lighting load. Feeder conductors that do not supply the entire load of the building or structure are to be calculated in accordance with Part III of Article 220. Feeder conductors supplying subdivided building loads are not required to be larger than the service or feeder conductors that supply the entire building or structure load. 220.87 Determining Existing Loads. The calculation of a feeder or service load for existing installations shall be permitted to use actual maximum demand to determine the existing load under all of the following conditions: * (1) The maximum demand data is available for a 1-year period. Exception: If the maximum demand data for a 1-year period is not available, the calculated load shall be permitted to be based on the maximum demand (the highest average kilowatts reached and maintained for a 15-minute interval) continuously recorded over a minimum 30-day period using a recording ammeter or power meter connected to the highest loaded phase of the feeder or service, based on the initial loading at the start of the recording. The recording shall reflect the maximum demand of the feeder or service by being taken when the building or space is occupied and shall include by measurement or calculation the larger of the heating or cooling equipment load, and other loads that might be periodic in nature due to seasonal or similar conditions. This exception shall not be permitted if the feeder or service has a renewable energy system (i.e., solar photovoltaic or wind electric) or employs any form of peak load shaving. * (2) The maximum demand at 125 percent plus the new load does not exceed the ampacity of the feeder or rating of the service. * (3) The feeder has overcurrent protection in accordance with 240.4, and the service has overload protection in accordance with 230.90. 220.88 New Restaurants. Calculation of a service or feeder load, where the feeder serves the total load, for a new restaurant shall be permitted in accordance with Table 220.88 in lieu of Part III of this article. The overload protection of the service conductors shall be in accordance with 230.90 and 240.4. Feeder conductors shall not be required to be of greater ampacity than the service conductors. Service or feeder conductors whose calculated load is determined by this optional calculation shall be permitted to have the neutral load determined by 220.61. Table 220.88 Optional Method - Permitted Load Calculations for Service and Feeder Conductors for New Restaurants Total Connected Load (kVA) All Electric Restaurant Not All Electric Restaurant Calculated Loads (kVA) Calculated Loads (kVA) 0-200 80% 100% 201-325 10% (amount over 200) + 160.0 50% (amount over 200) + 200.0 326-800 50% (amount over 325) + 172.5 45% (amount over 325) + 262.5 Over 800 50% (amount over 800) + 410.0 20% (amount over 800) + 476.3 Note: Add all electrical loads, including both heating and cooling loads, to calculate the total connected load. Select the one demand factor that applies from the table, then multiply the total connected load by this single demand factor. ENHANCED CONTENT Collapse The demand factors in 220.88 recognize the effects of load diversity that are typical of restaurants. It also recognizes the number of continuous loads as a percentage of the total connected load. The National Restaurant Association, the Edison Electric Institute, and the Electric Power Research Institute based the data for 220.88 on load studies of 262 restaurants. Those studies showed that the demand factors were lower for restaurants with larger connected loads. The service or feeder size is calculated by applying the appropriate demand factor from Table 220.88 to the total load (kVA). Part V. Farm Load Calculations 220.100 General. Farm loads shall be calculated in accordance with Part V. 220.102 Farm Loads - Buildings and Other Loads. (A) Dwelling Unit. The feeder or service load of a farm dwelling unit shall be calculated in accordance with the provisions for dwellings in Part III or IV of this article. Where the dwelling has electric heat and the farm has electric grain-drying systems, Part IV of this article shall not be used to calculate the dwelling load where the dwelling and farm loads are supplied by a common service. (B) Other Than Dwelling Unit. Where a feeder or service supplies a farm building or other load having two or more separate branch circuits, the load for feeders, service conductors, and service equipment shall be calculated in accordance with demand factors not less than indicated in Table 220.102(B). Table 220.102(B) Method for Calculating Farm Loads for Other Than Dwelling Unit Ampere Load at 240 Volts Maximum Demand Factor (%) The greater of the following: All loads that are expected to operate simultaneously, or 100 125 percent of the full load current of the largest motor, or First 60 amperes of the load Next 60 amperes of all other loads 50 Remainder of other loads 25 220.103 Farm Loads - Total. Where supplied by a common service, the total load of the farm for service conductors and service equipment shall be calculated in accordance with the farm dwelling unit load and demand factors specified in Table 220.103. Where there is equipment in two or more farm equipment buildings or for loads having the same function, such loads shall be calculated in accordance with Table 220.102(B) and shall be permitted to be combined as a single load in Table 220.103 for calculating the total load. Table 220.103 Method for Calculating Total Farm Load Individual Loads Calculated in Accordance with Table 220.102 Demand Factor (%) Largest load 100 Second largest load 75 Third largest load 65 Remaining loads 50 Note: To this total load, add the load of the farm dwelling unit calculated in accordance with Part III or IV of this article. Where the dwelling has electric heat and the farm has electric grain-drying systems, Part IV of this article shall not be used to calculate the dwelling load. Part VI. Health Care Facilities 220.110 Receptacle Loads. Receptacle loads calculated in accordance with 220.14(H) and (I) and supplied by branch circuits not exceeding 150 volts to ground shall be permitted to be subjected to the demand factors provided in Table 220.110(1) and Table 220.110(2) for health care facilities. Informational Note No. 1: See Article 100 for the definitions of patient care space categories. Informational Note No. 2: See 220.14(I) for the calculation of receptacle outlet loads. Table 220.110(1) Demand Factors for Receptacles Supplied by General-Purpose Branch Circuits in Category 1 and Category 2 Patient Care Spaces Portion of Receptacle Load to Which Demand Factor Applies (Volt-Amperes) Demand Factor (%) First 5000 or less 100 From 5001 to 10,000 50 Remainder over 10,000 25 Table 220.110(2) Demand Factors for Receptacles Supplied by General-Purpose Branch Circuits in Category 3 and Category 4 Patient Care Spaces Portion of Receptacle Load to Which Demand Factor Applies (Volt-Amperes) Demand Factor (%) First 10,000 or less 100 Remainder over 10,000 50 Part VII. Marinas, Boatyards, Floating Buildings, and Commercial and Noncommercial Docking Facilities 220.120 Receptacle Loads. General lighting and other loads in marinas, boatyards, floating buildings, and commercial and noncommercial docking facilities shall be calculated in accordance with Part III of this article and, in addition, the demand factors set forth in Table 220.120 shall be permitted for each service or feeder circuit supplying receptacles that provide shore power for boats. These calculations shall be permitted to be modified as indicated in Notes (1) and (2) of Table 220.120. Where demand factors of Table 220.120 are applied, the demand factor specified in 220.61(B) shall not be permitted. Informational Note: These demand factors could be inadequate in areas of extreme hot or cold temperatures with loaded circuits for heating, air-conditioning, or refrigerating equipment. Table 220.120 Demand Factors for Shore Power Receptacle Loads Number of Shore Power Receptacles Sum of the Rating of the Receptacles (%) 1-4 100 5-8 90 9-14 80 15-30 70 31-40 60 41-50 50 51-70 40 ò71 30 Notes: 1. Where shore power accommodations provide two receptacles specifically for an individual boat slip and these receptacles have different voltages (e.g., one 30-ampere, 125-volt and one 50-ampere, 125/250-volt), only the receptacle with the larger kilowatt demand shall be required to be calculated. 2. For each shore powered pedestal being installed that includes an individual kilowatt-hour submeters for each slip and is being calculated using the criteria listed in Table 220.120, the total demand amperes shall be permitted to be multiplied by 0.9 to achieve the final demand amperes of the facility. 3. If a circuit feeding a boat hoist and shore power for the same boat slip is shared, only the load with the larger kilowatt demand shall be required to be counted in the load calculation. Article 225 Outside Branch Circuits and Feeders Part I. General 225.1 Scope. This article covers requirements for outside branch circuits and feeders not over 1000 volts ac or 1500 volts dc, nominal, run on or between buildings, structures, or poles on the premises; and electrical equipment and wiring for the supply of utilization equipment that is located on or attached to the outside of buildings, structures, or poles. Informational Note: See Part IV of Article 235 for outside branch circuits and feeders over 1000 volts ac or 1500 volts dc. ENHANCED CONTENT Collapse Article 225 provides requirements unique to the installation of feeders and branch circuits outside (overhead and underground, not over 1000 volts ac or 1500 volts dc) of buildings and structures. These circuits may supply specific items of electrical equipment, or they may be the power supply to another building or structure. Examples of outside feeders and branch circuits include the following: * Conductors supplying the buildings of a multibuilding industrial complex or institutional campus * Outdoor supply conductors from an emergency system, a standby system, an alternative energy system, or on-site power generation * Supply conductors between a dwelling unit and a detached garage or other structure These requirements are in addition to the general requirements for branch circuits and feeders in Articles 210 and 215. 225.3 Other Articles. Application of other articles, including additional requirements to specific cases of equipment and conductors, is shown in Table 225.3. Table 225.3 Other Articles Equipment/Conductors Article Branch circuits 210 Class 1 power-limited circuits and Class 1 power-limited remote-control and signaling circuits 724 Class 2 and Class 3 remote-control, signaling, and power-limited circuits 725 Conductors for general wiring 310 Electrically driven or controlled irrigation machines 675 Electric signs and outline lighting 600 Feeders 215 Fire alarm systems 760 Fixed outdoor electric deicing and snow-melting equipment 426 Grounding and bonding 250 Hazardous (classified) locations 500 Marinas and boatyards 555 Medium-voltage conductors and cable 311 Messenger-supported wiring 396 Mobile homes, manufactured homes, and mobile home parks 550 Open wiring on insulators 398 Over 1000 volts, general 495 Overcurrent protection 240 Overcurrent protection for systems rated over 1000 volts ac, 1500 volts dc 245 Services 230 Services, feeders, and branch circuits over 1000 volts ac, 1500 volts dc 235 Solar photovoltaic systems 690 Swimming pools, fountains, and similar installations 680 Use and identification of grounded conductors 200 225.4 Conductor Insulation. Where within 3.0 m (10 ft) of any building or structure other than supporting poles or towers, open individual (aerial) overhead conductors shall be insulated for the nominal voltage. The insulation of conductors in cables or raceways, except Type MI cable, shall be of thermoset or thermoplastic type and, in wet locations, shall comply with 310.10(C). The insulation of conductors for festoon lighting shall be of the thermoset or thermoplastic type. Exception: Equipment grounding conductors and grounded circuit conductors shall be permitted to be bare or covered as specifically permitted elsewhere in this Code. ENHANCED CONTENT Collapse This exception and 250.184(A)(1), Exception No. 2, correlate to permit the use of the bare messenger wire of an overhead cable assembly as the grounded (neutral) conductor of an outdoor feeder circuit. 225.6 Conductor Size and Support. (A) Overhead Spans. Open individual conductors shall not be smaller than 10 AWG copper or 8 AWG aluminum for spans up to 15 m (50 ft) in length, and 8 AWG copper or 6 AWG aluminum for a longer span unless supported by a messenger wire. ENHANCED CONTENT Collapse The size limitation of copper and aluminum conductors for overhead spans is based on the need for adequate mechanical strength to support the weight of the conductors and to withstand wind, ice, and other similar conditions. The exhibit below illustrates overhead spans that are not messenger supported, are run between buildings, and are 1000 volts or less. The messenger cable provides the necessary mechanical strength rather than relying on the conductors. See also 396.10 for cable types permitted to be messenger supported. (B) Festoon Lighting. Overhead conductors for festoon lighting shall not be smaller than 12 AWG unless the conductors are supported by messenger wires. In all spans exceeding 12 m (40 ft), the conductors shall be supported by messenger wire. The messenger wire shall be supported by strain insulators. Conductors or messenger wires shall not be attached to any fire escape, downspout, or plumbing equipment. ENHANCED CONTENT Collapse Article 100 defines festoon lighting as “a string of outdoor lights that is suspended between two points.” The exhibit bel