Hi all, i want to know what happen if 250 - 500 kW motor and I connect it to 380V or 660V, what happen to the power consumption. what i think is
- using 660V will save money for the material?
- power consumption is still the same?

and what is the difference and which is more efficient by using delta or wye connection?


Thanks

To calculate power consumption for three phase:
P=3^?* E * I * cos theta, usually p.f.=0.8
use the highest amp reading for variable "E".
this will allow you to determine the cost benefit of operating in 380V or 660V. there are other factors to which to consider such as power source, ie. transformers necessary, application, and maintenance factor, etc. which can drive up your cost.

The voltage used will depend on the HP you need to perform the work.
Using Delta or a wye connection will depend on the motor application whether its for speed or torque applications.
There are many Wye-delta switching motor starters to consider.

power consumption is depends on the load torque at rated RPM, not depend on rated voltage, you can slect the size of the motor / rating of the motor depends on your load requirement. power consumtion would be nearly the same for any voltages, since finally the current through individul winding is the factor for losses.