CEE Relays Ltd

Tel:   +44 1753 576477    Fax: +44 1753 825661
FAQs: Using V3.8 Libraries in V4.0 and Higher
In V3.8 of PTW (and earlier versions), PTW's cable libraries and transformer libraries were stored in separate files (METRIC.CBL and IEC.XFR for example) from the rest of the PTW libraries (which were stored in, for example, PTW.LIB). In V4.0 and later, the cable and transformer libraries have been incorporated into the main library file. 
Also in V3.8, separate libraries were used for 50Hz and 60Hz networks. However, in V4.0 and later PTW automatically converts from the library frequency to the project frequency. 
Existing cable and transformer library files must be imported into the main PTW library using the V3.x import program (please contact us). It is important to ensure that the units (metric or imperial) and frequency (normally 50Hz or 60Hz) are entered correctly into the import program, or the data will be imported incorrectly. 
If you open a V3.8 project in V4.0 without running the import program, then the project and existing library files will be converted into the V4.0 format correctly, but the main library file will contain no cables or transformers.