Bus-Bar SC rating

Short circuit currents are governed by, firstly OMHs Law: Volts = Current x Resistance, second the energy to melt the material of the bus bar.

Your total power disipated over the second must be less than what would cause deformation of the bus bar. A safety factor, which I don't know, would then be added to prevent damage or danger.

can you please guide me to calculate the the total power dissipation as well as power that will cause the deformation of bus bar?

Ohms law is only one aspect of designing bus bar to withstand desired short circuit current.

Another equally important factor is bus bar bracing, which prevents bus bars from being ripped free of their supports as a result of attraction/repulsion during short circuit conditions.

Dear Sir,

Can u give me the details of the calculation for 50KA short circuit level

I f you are looking for SC of Panel there are no of factors,

1. Cross section of busbar

2. busbar material (cu/al)

3. distance between supports.

4. support strength.

etc.

Contact www.termate.com who have much information on this.

NEMA has a chart showing bus bar support spacing vs. cross section for various withstand ratings

will you please forward those NEMA Standard or link, so that I can go through it??

www.nema.org

Lot of factors come into play like configuration, spacing between supports .You can refer to any good electrical hand book