220 – Branch-Circuit, Feeder, and Service Load Calculations
220.12 and Table 220.12 – Lighting Load for Non-Dwelling Occupancies
Change at a Glance:
Section 220.12 and Table 220.12 has been extensively revised. Reduced lighting loads in most occupancies was achieved. Dwelling and multi-family dwelling units were moved out of Table 220.12 and referenced in revised 220.14(J).
220.12 Lighting Load for Specified Non-Dwelling Occupancies.
(A) General. A unit load of not less than that specified in Table 220.12 for occupancies specified shall constitute non-dwelling occupancies and the floor area determined in 220.11shall be used to calculate the minimum lighting load. The floor area for each floor shall be calculated from the outside dimensions of the building, dwelling unit, or other area involved. For dwelling units, the calculated floor area shall not include open porches, garages, or unused or unfinished spaces not adaptable for future use. Motors rated less than 1⁄8 HP and connected to a lighting circuit shall be considered general lighting load.
Informational Note: The unit values of Table 220.12 are based on minimum load conditions and 100 percent power factor and may not provide sufficient capacity for the installation contemplated.
(B) Energy Code. Exception No. 1: Where the building is designed and constructed to comply with an energy code adopted by the local authority, the lighting load shall be permitted to be calculated at using the unit values specified in the energy code where the following conditions are met:
(1) A power monitoring system is installed that will provide continuous information regarding the total general lighting load of the building.
(2) The power monitoring system will be set with alarm values to alert the building owner or manager if the lighting load exceeds the values set by the energy code. Automatic means to take action to reduce the connected load shall be permitted.
(3) The demand factors specified in 220.42 are not applied to the general lighting load.
(4) The continuous load multiplier of 125 percent shall be applied.
Exception No. 2 Where a building is designed and constructed to comply with an energy code adopted by the local authority and specifying an overall lighting density of less than 13.5 volt-amperes/m2 (1.2 volt-amperes/ft2), the unit lighting loads in Table 220.12 for office and bank areas within the building shall be permitted to be reduced by 11 volt-amperes/ m2 (1 volt-amperes/ft2).
Table 220.12 General Lighting Loads by Non-Dwelling Occupancy
(See NEC and Table 220.12 provided in this text)
220.14(J) – Unit Loads for Dwelling Units
Change at a Glance:
The NEC calculation of 3.0 watts per square foot for dwelling units was moved from Table 220.12 to 220.14(J) and reference to Table 220.12 was removed from 220.14(J).
220.14 Other Loads – All Occupancies
(J) Dwelling Occupancies Units. In one-family, two-family, and multifamily dwellings and in guest rooms or guest suites of hotels and motels, the minimum unit load shall be not less than 33 VA volt-amperes/m2 (3 VA volt-amperes/ft2). The lighting and receptacle outlets specified in 220.14(J)(1), (J)(2), and (J)(3) are included in the minimum general lighting load calculations of 20.12 unit load. No additional load calculations shall be required for such outlets. The minimum lighting load shall be determined using the minimum unit load and the floor area as determined in 220.11 for dwelling occupancies. Motors rated less than 1⁄8 hp and connected to a lighting circuit shall be considered part of the minimum lighting load.
(1) All general-use receptacle outlets of 20-ampere rating or less, including receptacles connected to the circuits in 210.11(C)(3) and 210.11(C)(4)
(2) The receptacle outlets specified in 210.52(E) and (G)
(3) The lighting outlets specified in 210.70(A) and (B)
220.42 – Lighting Load Demand Factors
Change at a Glance:
Hospitals were deleted from Table 220.42 and is now required to include 100 percent of the total VA of the calculated lighting load.
220.42 General Lighting.
The demand factors specified in Table 220.42 shall apply to that portion of the total branch-circuit load calculated for general illumination. They shall not be applied in determining the number of branch circuits for general illumination.
Table 220.42 Lighting Load Demand Factors
(See NEC and supplied table for complete NEC text of table)
220.53 – Appliance Load — Dwelling Unit
Change at a Glance:
All household electric cooking equipment that is fastened in place (not just an electric range) has been added to the list of appliances that cannot be included in the four or more appliances eligible for a 75% derating demand factor.
220.53 Appliance Load — Dwelling Unit(s).
It shall be permissible to apply a demand factor of 75 percent to the nameplate rating load of four or more appliances rated 1/4 hp or greater, or 500 watts or greater, that are fastened in place, other than electric ranges, clothes dryers, space-heating equipment, or air-conditioning equipment, and that are served by the same feeder or service in a one-family, two-family, or multifamily dwelling. This demand factor shall not apply to:
(1) Household electric cooking equipment that is fastened in place
(2) Clothes dryers
(3) Space heating equipment
(4) Air-conditioning equipment