33 KV system

You have to change the Transformer and the switchgears. May not be worth it.

If you are sure of future expansion in load, you can retain the 33kV Switchgear already procured & installed and extend 11kV supply to the same for the time being. Nothing will happen.

But, the same cannot be told of the transformer. If you have a 33kV/415V Transformer and extend only 11kV to it, the LV side voltage will only be 1/3rd of 415V. So, you MUST replace the transformer with a 11kV/415V one.

Buy a 33/11/415 Volts transformer.So u can change over easily.This is a standard method we have used in Many places.

You will have to change your transformer(s) and may have a problem on capacity. 33kv system tranlates to a small amperage capability; so for lower voltage, the amperage goes up for the same total KVA. Your switchgear may not take it; the higher amperage, and perhaps your controls and protection schemes change alot. Long story, short ending, take service at 33 KV, the cost of conversion would be excessive and a waste of money considering your statement of load increases may eventually require 33 kv service anyway.