156 lines
5.4 KiB
Markdown
156 lines
5.4 KiB
Markdown
---
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id:
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aliases:
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- nec-220
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tags:
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- authorship/other
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- destiny/uncertain
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- status/incomplete
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- topic/construction/electrical
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- type/media
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title: Article 220 Branch-Circuit, Feeder, and Service Load Calculations
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---
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# Article 220 Branch-Circuit, Feeder, and Service Load Calculations
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## Part I. General
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### 220.1 Scope.
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This article provides requirements
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for calculating branch-circuit, feeder, and service loads.
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Part I provides general requirements for calculation methods.
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Part II provides calculation methods for branch-circuit loads.
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Parts III and IV provide calculation methods for feeder and service loads.
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Part V provides calculation methods for farm loads.
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Informational Note No. 1:
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See examples in Informative Annex D.
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Informational Note No. 2:
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See Figure 220.1 for information on the organization of Article 220.
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### Figure 220.1 Branch-Circuit, Feeder, and Service Load Calculation Methods.
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<!-- TODO: FIGURE OMITTED -->
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<!-- TODO: TEXT OMITTED -->
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### 220.14 Other Loads -- All Occupancies.
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In all occupancies, the minimum load for each outlet
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for general-use receptacles and outlets not used for general illumination
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shall not be less than that calculated in 220.14(A) through (M),
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the loads shown being based on nominal branch-circuit voltages.
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Exception:
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The loads of outlets serving switchboards and switching frames in telephone exchanges
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shall be waived from the calculations.
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<!-- TODO: TEXT OMITTED -->
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#### 220.14(A) Specific Appliances or Loads.
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An outlet for a specific appliance
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or other load not covered in 220.14(B) through (M)
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shall be calculated based on the ampere rating
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of the appliance or load served.
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#### 220.14(B) Electric Dryers and Electric Cooking Appliances in Dwellings and Household Cooking Appliances Used in Instructional Programs.
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Load calculations shall be permitted
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as specified in 220.54 for electric dryers
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and in 220.55 for electric ranges and other cooking appliances.
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#### 220.14(C) Motor Outlets.
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Loads for motor outlets shall be calculated
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in accordance with the requirements in 430.22, 430.24, and 440.6.
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#### 220.14(D) Luminaires.
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An outlet supplying luminaire(s) shall be calculated
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based on the maximum volt-ampere rating of the equipment
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and lamps for which the luminaire(s) is rated.
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#### 220.14(E) Heavy-Duty Lampholders.
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Outlets for heavy-duty lampholders
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shall be calculated at a minimum of 600 volt-amperes.
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#### 220.14(F) Sign and Outline Lighting.
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Sign and outline lighting outlets
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shall be calculated at a minimum of 1200 volt-amperes
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for each required branch circuit specified in 600.5(A).
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#### 220.14(G) Show Windows.
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Show windows shall be calculated
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in accordance with either of the following:
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* (1) The unit load per outlet as required in other provisions of this section
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* (2) At 200 volt-amperes per linear 300 mm (1 ft) of show window
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#### 220.14(H) Fixed Multioutlet Assemblies.
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Fixed multioutlet assemblies used in other than dwelling units
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or the guest rooms or guest suites of hotels or motels
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shall be calculated in accordance with (H)(1) or (H)(2).
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For the purposes of this section,
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the calculation shall be permitted
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to be based on the portion that contains receptacle outlets.
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* (1) Where appliances are unlikely to be used simultaneously,
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each 1.5 m (5 ft) or fraction thereof
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of each separate and continuous length
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shall be considered as one outlet of not less than 180 volt-amperes.
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* (2) Where appliances are likely to be used simultaneously,
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each 300 mm (1 ft) or fraction thereof
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shall be considered as an outlet of not less than 180 volt-amperes.
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#### 220.14(I) Receptacle Outlets.
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Except as covered in 220.14(J) and (K),
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receptacle outlets shall be calculated at not less than 180 volt-amperes
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for each single or for each multiple receptacle on one yoke.
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A single piece of equipment consisting of a multiple receptacle
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comprised of four or more receptacles
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shall be calculated at not less than 90 volt-amperes per receptacle.
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This provision shall not be applicable to the receptacle outlets
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specified in [[nfpa-70_210_branch-circuits#210.11(C)(1) Small-Appliance Branch Circuits.|210.11(C)(1)]]
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and [[nfpa-70_210_branch-circuits#210.11(C)(2) Laundry Branch Circuits.|(C)(2)]].
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#### 220.14(J) Dwelling Units.
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In one-family, two-family, and multifamily dwellings,
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the minimum unit load shall be not less than 33 volt-amperes/m$^2$ (3 volt-amperes/ft$^2$).
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The lighting and receptacle outlets specified in 220.14(J)(1), (J)(2), and (J)(3)
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are included in the minimum unit load.
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No additional load calculations shall be required for such outlets.
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The minimum lighting load shall be determined using the minimum unit load
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and the floor area as determined in 220.11 for dwelling occupancies.
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Motors rated less than 1⁄8 hp and connected to a lighting circuit
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shall be considered part of the minimum lighting load.
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* (1) All general-use receptacle outlets of 20-ampere rating or less,
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including receptacles connected to the circuits in 210.11(C)(3) and 210.11(C)(4)
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* (2) The receptacle outlets specified in 210.52(E) and (G)
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* (3) The lighting outlets specified in 210.70
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#### 220.14(K) Office Buildings.
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In office buildings, the receptacle loads
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shall be calculated to be the larger of (1) or (2):
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* (1) The calculated load from 220.14(I)
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after all demand factors have been applied
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* (2) 11 volt-amperes/m$^2$ or 1 volt-ampere/ft$^2$
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#### 220.14(L) Other Outlets.
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Other outlets not covered in 220.14(A) through (K)
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shall be calculated based on 180 volt-amperes per outlet.
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<!-- TODO: TEXT OMITTED -->
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