ElumTools can only calculate luminaires that are Lighting Fixture families. If you have Lighting Fixture families that are nested in non-Lighting Fixture host families, ElumTools cannot detect these as a luminaire by default.

Solution:

ElumTools can recognize the Lighting Fixture family if the Nested family is Shared with the Host family. 

1. Open the Host Family in Family Editor.

2. Select the Nested Lighting Fixture family, and open that in Family Editor.

3. Set the Lighting Fixture Family as Shared in the Properties as shown below.

4. Load the Nested Family into the Host family, and select "Overwrite the existing version and its parameter values".

5. Load the Host family into the project, and once again select "Overwrite the existing version and its parameter values".

If done correctly, ElumTools should now be able to calculate the nested Lighting Fixture family, and it should be visible in Luminaire Manager.