In almost every submersible installation we use three-phase power to run the down hole motors and you add the three transformers KVA together to get the total full load capability.
• KVA = (SV x NPA x 1.732) / 1000
• Let’s assume that we have a 225-HP, 57-amp motor with a required surface voltage of 2617 volts. Then:
KVA = (2617 x 57 x 1.732) / 1000 = 258
• Now we want to size our transformers equal to or greater than the required KVA.
• Never undersize the transformer bank because you can burn up the transformers and motor.
• The WG ESP catalog has a listing of transformers (reference Figure 6.2).
• Transformers come only in standard sizes.