Greeting,
We have a plane for a distribution substation 34.5kV. We got two proposals as follow:
1) To use single bus (no sections), and all CBs will be double due to high current demand that normally will exceed 4000A. the max widely used CB found in the market for this level is 3150A. This bus will be loaded up to 250MVA, and this option has been provided as cost effective solution.
2) To increase the number of buses, and hence the number of incomming lines and transformers feding these buses will also increase. Therefore, there will be no need for the double CB’s as a 3150A CB scheme can handle.
From the above, I need your input to evaluate the followings:
1) The impact on safety, and the IEC/safety standard call or objections.
2) Is there any MTBF statistics for 34.5kV double scheme vs. single scheme?
3) Impact on short circuit current, and arc flash.
I would appreciate you support and help for having the right/accepted option.
We have a plane for a distribution substation 34.5kV. We got two proposals as follow:
1) To use single bus (no sections), and all CBs will be double due to high current demand that normally will exceed 4000A. the max widely used CB found in the market for this level is 3150A. This bus will be loaded up to 250MVA, and this option has been provided as cost effective solution.
2) To increase the number of buses, and hence the number of incomming lines and transformers feding these buses will also increase. Therefore, there will be no need for the double CB’s as a 3150A CB scheme can handle.
From the above, I need your input to evaluate the followings:
1) The impact on safety, and the IEC/safety standard call or objections.
2) Is there any MTBF statistics for 34.5kV double scheme vs. single scheme?
3) Impact on short circuit current, and arc flash.
I would appreciate you support and help for having the right/accepted option.
