Bus Wire Design

• Buss wire or bus wire is copper wire coated in tin to protect from corrosion. Buss wire can be further shielded by plastic, rubber, or metal layers. According to "Powerboater's Guide to Electrical Systems, Second Edition" by Edwin Sherman, "tinning does a great job at resisting corrosion at terminals as well as preventing oxidation from migrating up the wire under insulation, a common problem with untinned wire". Buss wire is available in standard American Wire Gauge (AWG) sizes. According to "Electrical Power Cable Engineering" by William Thue, "the wire of the concentric neutral shall be applied directly over the insulation shield with a lay of not less than six or more than ten times the diameter of the concentric wires". ASTM has standards for tin copper bus wire based on the intended application and whether the tin copper wire has a steel core.
  
  

ASTM B33

• ASTM B33 is the standard specification for tin-coated soft or annealed copper wire when it is for electrical purposes. The tin coating on the wire must not have any interruptions. This is verified using a hydrochloric acid-sodium polysulfide test. Wire diameter is measured via a micrometer caliper equipped with a vernier according to ASTM standard B258.
  
  

ASTM B520

• ASTM standard B520 is the specification for tin-coated, copper-clad steel wire for use in electronics. Electrical resistivity for this type of wire is measured according to ASTM standard B193, the test method for resistivity of electrical conductor materials. The copper core of the bus wire must meet ASTM standard B49.
  
  

ASTM B965

• ASTM standard B965 gives the specifications for high performance tin-coated annealed copper wire that is both electrically conductive and can be soldered. ASTM 965 applies to class T30HS, T30A, T40HS and T40A steel wires. The steel wire must have nominal conductivity between 30 and 40 percent. The tin coated copper clad wire can be hard drawn or annealed. The copper clad steel wire inside the tin coating must meet ASTM standard B452.
  
  

IEC 11801

• Tin copper bus wire can be used for grounding cables to prevent electrocution.Hemera Technologies/AbleStock.com/Getty Images
  
  The International Electrotechnical Commission (IEC) has design standards for cabling. A drain wire is required by IEC standard 11801. The drain wire grounds the cable so that accidental contact does not cause electrocution. Tin copper bus wire can be a drain wire. IEC standard 11801 is shared with the International Standards Organization (ISO).