How to Properly Caculate Demand Load

[ASG]

I've worked on many renovations from retail to office space jobs (NYC mostly) but a comment I just got on a recent job is making my head explode

Basically he's saying regardless of me knowing the exact wattage of every lighting fixture, I should be using table 220.12 to determine my lighting demand.

Besides that seeming just dumb on its face (why would I use a generic number when I know the what the largest lighting load would be?), these loads wouldn't even meet the Energy Code without a lot of exceptions being applied (which I guess wouldn't even count because that wouldn't be "general lighting").

 

[dkidd]

Exception: 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 the 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.
(3) The demand factors specified in 220.42 are not applied
to the general lighting load.

2014

 

[ASG]

Exception: 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 the 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.
(3) The demand factors specified in 220.42 are not applied
to the general lighting load.

2014

1) In NYC, we are still on 2008 NEC.
2) That would still mean I'd have to use the energy code and not the load of the actual fixtures.

 

[iwire]

1) In NYC, we are still on 2008 NEC.
2) That would still mean I'd have to use the energy code and not the load of the actual fixtures.

No, that would mean your service and feeder calculation would be based on article 220 but you could not install that much load.

You are right, it makes little sense, I suspect that is why in the 2014 they provide relief.