Silver plated copper busbar

Dear sir,
Please advise me, what is the purposed of silver plated for electrical busbar and where is to plated on the bar, just a connecting point or full length?

Thank you so much in advance.

Best Regards,

Silver has the highest electrical conductivity of any other metal. Low contact resistance is also a factor to consider. The only problem I see with silver plated buss bars is that silver is soft and would wear down easily especially if you are rack plating. Like any buss bar you have to remove chemical residue build-up and oxidation to maintain good electrical contact. This scrubbing will wear down the silver plate as well. If you have to use plated silver the thickness should be heavy enough so you don't have to replate the bar once per week. The whole bar should be plated in silver, including the edges. This will eliminate current fluctuation across the surface of the bar. Good Luck!