Hi
Can anyone tell me if I can replace my three controllers for my 14w tubes with this product
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
No my tubes are T8 Or so I'm led to believe
http://www.arcadia-uk.info/product.php?pid=18&mid=12&lan=en&sub=&id=4
Using the fsu15 lamp
Using these controllers at present
http://www.arcadia-uk.info/product.php?pid=75&mid=12&lan=en&sub=&id=4
Using the acup15 controller
I was confused by your statement "my 14w tubes". 
Sorry
I did get it wrong they are 15w it's just the controller says 14/15w on its label. But 15 watt bulbs they are
CCFL power supplies are quite tricky. The characteristics of the lamp must match the characteristics of the inverter for proper operation. CCFLs are driven by current, not voltage. The inverter needs to supply enough voltage to start them up and then regulate the output current to the proper level. LT has a lot of appnotes on CCFL power supplies, something to look at to understand how they operate.