How to choose the sizes of flat copper busbar?

05/21 admin 901

Standard Copper Bar Current Capacity

Estimation method:

Single copper bus bar current capacity= width(mm)*thickness coefficient

Double copper bus bar current capacity= width(mm)*thickness coefficient*1.5 (empirical coefficient)

Copper bar and aluminum bar can also be estimated as square terms, usually copper should be 5-8A/sq, Aluminum should be 3-5A/sq.


Common copper bar current capacity method:

Copper bar current capacity when 40℃ = bar width(mm)*thickness coefficient

(thickness coefficient is 20 when bar width is 12(mm);it is 18 when bar width is 10; it is successively: [12-20,10-18,8-16,6-14,5-13,4-12]

Double copper bars[40℃]=(1.56-1.58)*single copper bar[40℃] (according to the size of section)

Three layers copper bars[40℃]=2*single copper bar[40℃]

Four layers copper bars 40[℃]=2.45*single copper bar[40℃] (not suggested option,replacing with special bus bar is better.)

Copper bar[40℃]=0.85*copper bar[25℃]

Aluminum bar [40℃] =1.3*copper bar[25℃]

For example: To count the 100*10 section copper bar current capacity,

One layer:100*18=1800(A)

Two layers:Current Capacity of 2( 100*10) is :1860*1.58=2940(A)

Three layers:Current Capacity of 3( 100*10) is :1860*2=3720(A)


Common copper bar sizes and current capacity form:

  1. Rectangular copper bar

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