Lighting Load and Service Sizing - Table 220.12 (2011 NEC)

Status
Not open for further replies.
S

Steamdonkey2011

Member
Location
Boise, Id
The older and wiser engineers at my firm say I don't need to worry about Table 220.12 when sizing the service for an office building. They're telling me the connected lighting load is what I should base my calculations on. Is this stated somewhere in the Code? Thanks...
 
Steamdonkey2011 said:
The older and wiser engineers at my firm say I don't need to worry about Table 220.12 when sizing the service for an office building. They're telling me the connected lighting load is what I should base my calculations on. Is this stated somewhere in the Code? Thanks...
Click to expand...

It depends on which is the larger load.

220.12 Lighting Load for Specified Occupancies. A unit
load of not less than that specified in Table 220.12 for
occupancies specified therein shall constitute 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.
Informational Note: The unit values herein are based on
minimum load conditions and 100 percent power factor and
may not provide sufficient capacity for the installation
contemplated.
 
NEC wins...

NEC wins...

Unless specifically exempted by your local or state's adopted electrical code, the NEC prevails for minimum lighting loads.

The City of Los Angeles plan check office allows our plans to show the actual connected lighting load in our lighting panel schedule as long as we show the minimum load per the NEC in our overall load summary of the facility.

The State of CA's energy compliance is also far below the minimum load amount in the NEC.
 
The NEC doesn't win here. Washington State administrative codes allow us (require us, actually) to calculate lighting load on the basis of energy code requirements, even though those are lower than the NEC lighting allowances.
 
Steamdonkey2011 said:
The older and wiser engineers at my firm say I don't need to worry about Table 220.12 when sizing the service for an office building. They're telling me the connected lighting load is what I should base my calculations on. Is this stated somewhere in the Code? Thanks...
Click to expand...

The NEC does not include energy management requirements such as imposed in both CA (Title 24) and WA (WAC 51). Check the State Energy codes that regulate lighting strategies in your local AHJ conservation requirements. (I.e. Fenestration incident light can offset controlled illumination requirements.)
 
Status
Not open for further replies.
Top