19) Calculation Example

19) Calculation Example

Up till now we have seen all the theoretical part of bus bar design & all the formulae which are required for calculating short ckt forces & stress.
Now will take one practical example for busbar calculation for better understanding.

The example is divided in three steps

Step 1) In this we are going to collect the system data for which busbar system is to be designed & then calculate derating factors for ambient temperature, ventilation& proximity effect. Then we will calculate effective derating factor & calculate the busbar size.

Step 2) After selecting the busbar calculate the value of “as” this is used to calculate peak electromagnetic short ckt forces between phase & between sub conductors. Then calculate peak electromagnetic short ckt forces between phase & between sub conductors. Then calculate total stress on busbar.

Step3) Adjustment should be carried out to maintain the stress within limit of busbar; accordingly busbar support must be selected.