With a 6 lead, dual voltage motor, you connect it in wye for the higher voltage and in delta for the lower voltage. In this case your motor will have windings rated at 2300 volts and when connected in delta to a 2300 volt source each winding will see its rated voltage. When you connect the motor in a wye for the higher voltage each winding will see the supply voltage divided by the square root of 3. 4160/square root of 3 = 2400 volts.
The code only applies to T&M work....it does not apply to contract work.