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Why must Copper Bus Bar be Tin Plated?
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Sir,
Why we need Tin Plated Copper bar to be used in 6.9 KV busbar interconnection. My question is What is special with Tin Coating for copper bar?
Thanks and Regards,
Oil Co. - Abu Dhabi, UAE
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Copper oxidizes and the oxides do not stay on the copper well. When they come off there is more copper exposed, which in turn oxidizes, and so-on. Also the oxides do not conduct well. This causes poor electrical contact, which then gets hot and increases the oxidation rate. The oxides, because of their poor conductivity, also cause arcing at the electrical contacts, eroding the copper.
Tom Gallant- Long Beach, California, USA
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Tin plating has two main technical advantages:
1. The thin tin oxide film (10-30 nm) forms on the surface of the tin coating could act as a shield, inhibiting further oxidation; and
2. Being a relatively soft metal, tin provides a low constriction resistance.
T.S.N. Sankara Narayanan
- Chennai, Tamilnadu, India
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Tin plate works well to prevent corrosion and provide a good, clean contact surface. However, I prefer to heat the end of the copper end of the part to be coated, apply flux and then melt solder onto the surface, which I smooth out with a solder brush. Use lots of flux(soldering paste). The final step is to smooth our the coating and eliminate lumps and drips with a wet rag, wiping quickly to remove excess material.
Come to think of it, it might be easier to tin plate! Why didn't I think of that?
The advantage of soldering the connection surface is the heavy coating that results.
Daryl P. Spindler, Sr., CEF
- Greenbrier, Tennessee
November 4, 2009
we are manufacturing different types of Copper/Aluminium Busduct as well as panels; in these systems we use lot of copper, we inquire the effect of tinning on Copper Bus & Aluminium Bus (meaning Current Capacity ie how many percent increase in current )
Jagdishpower systems - Nashik, Maharastra, India
April 22, 2010
Why bare copper bus bar turns black colour in power control panel?
Samirendu Ray- Indore, M.P, India.
November 18, 2010
Why black colour marks are formed on the tin coated busbars of the new panel board which not yet energized
krishna rajstudent - Mumbai, India
November 18, 2010
Hi.
Black discoloration of metals is often a sign of the presence of sulphides. But if you send a photo of the marks, people may be able to help you more.
Regards,
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 Ted Mooney, P.E. finishing.com Brick, New Jersey |
December 22, 2011
Q. Dear sir,
I am studying types of plating used for industrial application and to get more information, I went through website, visited a small industry (who does plating on conductors), and I have some queries.
Which plating is best for copper-copper and copper-aluminium and aluminium-aluminium contacts.
Most of the companies do silver plating, tin plating, nickel plating, etc.
How should we make difference between these types of plating, and what factors we should consider?
thanking you
Sanj
- Mumbai, India
December 26, 2011
Hi, Sanj. May we assume you are referring to plating of bus bars? If you are talking about other kinds of contacts, this becomes an electrical engineering project to look at the voltages, currents, arcing, durability, contact pressure, required reliability, etc., etc.
For bus bar the standard would be to plate any aluminum completely with copper first, and then to plate the copper contact surfaces with tin. It is possible, however, to more directly plate aluminum with tin.
Regards,
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Ted Mooney, P.E. finishing.com Brick, New Jersey |
December 30, 2011
By theory, normally for joints we do plating, and silver plating has less resistivity than tin and nickel plating so joint resistance will be good in case of silver plating.
But is it really practically possible to plate aluminium with copper and then plate it with tin?
Whether it will not affect the current carrying capacity and will not create any chemical reaction (copper + aluminum + tin plating)
and I want to know that what will be the basic factor to select one plating from these three types of platings.
Specially, how current density will be affected?
regards
sanj
- india, mumbai
December 30, 2011
Hi, Sanj.
Yes, entire manufacturing plants have been devoted to making aluminum bus bar and plating it with copper. Atotech used to offer, and may still offer, their Alstan process for plating aluminum directly with tin, skipping the copper plating step.
Certainly galvanic corrosion is possible any time any object is partially covered in one metal and partially covered with another metal, such as is the case with copper bus with tinned or silvered ends, but exposure conditions determine whether this is an actual problem or simply a potential concern.
Nickel plating tends to be hard, and it is used for contact surfaces such as battery chargers. Tin is significantly less expensive than silver, but the conductivity is lower and in some cases tin whiskers could be a problem.
Regards,
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Ted Mooney, P.E. finishing.com Brick, New Jersey |