Re: How to Calculate the Bus Bar Size

Home Electrical Engineering Forum General Discussion How to Calculate the Bus Bar Size Re: How to Calculate the Bus Bar Size


Hi Abdul,

I was browsing net found out your concern might be helpful to solve your problem.

Smorkos is correct. You should have consider by calcualting the actual short circuit current on the system(sym & assym value) and the bus bar holder. This is the basis for calculating the mechanical strenght of the bus Bus bar calcualtion to be safe and protect for max. short circuit current (KA) during fault condiotn. The formula is not easy you have to consider the following items:

EMF between bus bar

Bus bar arrangement

Mechanical forace action supporters

mechanical force or tensile strength on bus bar

flexure of bus bar

Thermodyanmic consideration

Those mentioned above shall be consider in calcualting the bus bar

TIp: Vendor has data and formula of  bus bar size with respect to the total consumer Loas (amps)

As i can see and experience 35*4 is economically with a safe factor of 152% based on the Transformer rated current.

Hope this will help