15 MVA Power Transformer

Hello,

1. Can u guide me which is the preferred vector group for 132KV/33 KV Power transformer ? its rating is 15 MVA and application is Industrial ,this trafo will feed power at 33 KV to 1 no. of 10 MVA furnace Transformer and 2 Nos of 2.5 MVA Auxiliary Transformers

2. If Ynyn0 is selected then can the both side(132 KV and 33 KV) Neutral connected to common Substation Earth Grid??