Hello,
imagine to have a switchgear with a double busbar and a bus tie NC. Connected to it, there are 4 generators each capable of generating 100 amps, working in parallel, and 8 motors whose FLC is 50A. In normal condition every section of the busbar is crossed maximum from 50A (in green in the attached picture); in worst case scenario, i.e. all generators on one side and all the loads on the other side, the maximum current that crosses a busbar section is 200A. So to me looks reasonable that this should be the sizing current; instead, normally the busbars are sized on the sum of the loads (+ a spare %) or the sum of the generators' currents. Is there any standards reference for this? What is your opinion?
imagine to have a switchgear with a double busbar and a bus tie NC. Connected to it, there are 4 generators each capable of generating 100 amps, working in parallel, and 8 motors whose FLC is 50A. In normal condition every section of the busbar is crossed maximum from 50A (in green in the attached picture); in worst case scenario, i.e. all generators on one side and all the loads on the other side, the maximum current that crosses a busbar section is 200A. So to me looks reasonable that this should be the sizing current; instead, normally the busbars are sized on the sum of the loads (+ a spare %) or the sum of the generators' currents. Is there any standards reference for this? What is your opinion?
