It is possible to use more than one project to complete larger designs. It is important to bear in mind, however, that separate projects will not be connected for functionality such as cross referencing, wire and device numbering, etc. so much of the advantage of using electrical CAD will usually be lost.
A possible strategy is to divide designs up into sub-systems, such as power and control, where cross referencing is not as critical. If you wish to continue to access the full benefits of electrical CAD but need more than 15 pages we are able to suggest some purchased solutions.
Please submit a support request with details of the number of pages that would meet your needs and advising your location.