Wattage Parameter for Lighting Fixtures

[Anonymous]

I've noticed that when making a Lighting Fixture Schedule there is a built-in parameter for Wattage that can be included as a field. This Wattage Parameter can be applied to any family that has a light source but when I search through the family I can't find the corresponding built-in parameter. It's not in the project Properties panel, project Type Properties Menu, or the Family Types Menu in the family. Nor is it found in the properties of the actually light source. I know that the parameter is in the family because it can be used in formulas for parameters. Does anyone know where to locate this parameter and if it is actually hidden for a reason, does anyone know the reason why? Thanks.

[Anonymous]

More information to the puzzle.

The Wattage built in parameter directly influences the light source. As can be seen by the attached two images. In the schedule I set the Apparent Power to 30 VA and the Wattage to 50 W. In the Initial Intensity field it shows that Wattage for the light source is 50 W. As can be seen, I am able to change the Apparent Power with the Wattage Parameter but in my application I want to be able to influence the Wattage with the Apparent Power Parameter. But since I can't find the Wattage Parameter I'm guessing that this might not be possible. 

[MuirEng]

Hi,

Wattage is a portion of one representation of the Initial Intensity parameter. Revit lets you enter the parameter in a few ways (Wattage + efficacy, flux, intensity, illuminance + distance) but in the end it is just one thing that drives out to a bunch of read only versions. This parameter cannot be set by formula. 

As I am sure you know the idea is that this field represents how much light you get from the fixture. 

The apparent power parameter deals with power input. Yes, there is a relationship between the watts in and watts out + efficacy but you can only work it in one direction, as you have discovered.

Do you need to schedule both power in and intensity?

We create separate family types for all the different power model fixtures in a line, and our schedules show (titles in "") apparent power ("Load") and luminous flux ("Lumens"). Could that work for you?

Perhaps if I understood why you are trying to do this I could make a suggestion.