Fluorescent ballasts

Using Arduino General Electronics
2

They don't make a model for 3x15W T8 bulbs so I assume your bulbs are T5 style (thinner than T8).

For T5 bulbs use:
Type: PC 3/4/14 T5 PRO lp
Model: 22176315

Full catalog:
http://www.tridonic.com/com/en/download/Product_catalogue_2010_ENG.pdf