Can you replace DY11 by DYN11 transformer?

Yes, you can replace a DY11 transformer with a DYN11 transformer, but it is important to consider the differences in their winding configurations and phase shifts. The DY11 transformer has a wye (star) connection on the primary side and a delta connection on the secondary side, while the DYN11 transformer has a delta connection on the primary side and a wye connection on the secondary. This change in configuration may affect voltage levels and phase relationships in your system, so it's essential to ensure compatibility with existing equipment and load requirements. Always consult with an electrical engineer before making such a replacement.