How do I determine busbar junction resistance?
How do I determine busbar junction resistance?
(OP)
I am looking for advice on determining 'tyupical' busbar junction resistances. My applications run up to 50kADC. Usually minor losses aren't critical to me, but sometimes I need to be able to estimate what's going to happen every 12 feet when I bolt all that copper together. Any advice?
Paul Matejcek
Paul Matejcek






RE: How do I determine busbar junction resistance?
For a good connection (suitable area, flat, free of oxide and bolted with hardware giving the right force in the whole temperature range) the loss is usually negliable.
RE: How do I determine busbar junction resistance?
Thanks for the lead. I didn't find that document on the US CDA page. I briefly browsed the article on joints at the UK site, and it looks as though it will be helpful.
Regards,
Paul Matejcek
RE: How do I determine busbar junction resistance?
RE: How do I determine busbar junction resistance?
Thanks -- I understand Ohm's Law, and how to get the data empirically. My questions was about predicting the resistance. Based on what I have learned today, it seems not to matter, because a well-made overlap joint (the sort I'm using) has a lower resistance than a similar length of bus.
Thanks again,
Paul Matejcek
RE: How do I determine busbar junction resistance?
Run 100Amps DC from a current generator and read the voltage drop on the contact. The higher the temperature the higher the drop voltage.
That means resistance is not constant!!!
Traian
RE: How do I determine busbar junction resistance?
But I wanted to mention that Busbar's point was not simply a statement of ohm's law. He was explaining the 4-wire resistance measurement principle which almost entirely eliminates errors from lead resistance and probe contact resistance. Simple resistance measurements with 2-lead multimeter/ohmmeter are not nearly as accurate when measuring low resistances. Also a good discussion by Traian.
RE: How do I determine busbar junction resistance?
Paul