Aluminum Bus Bar Current Carrying Capacity

Let s have a simple example of 4 sqmm bus bar.

Aluminum bus bar current carrying capacity.

Free air conditions assume some air movement other than convection currents and may be applicable for outside installations. What is an ampacity chart. Generally current carrying capacity of al. Copper has excellent mechanical and electrical characteristics and for many years was the metal of choice for use as bus conductor.

Ratings are for frequencies up to 60 hz. However the trend has been toward wider use of aluminum for all types of bus installa tion. The aluminium bus bar widely used and most popular than copper busbar. The aluminium bus bar is cheaper than copper busbar but the resistivity of the aluminium busbar is high as compared with copper busbar.

These standards give maximum temperature rises as well as maximum ambient temperatures. Aluminium busbar current carrying capacity 0 8 busbar width thickness in amps. Ratings apply for single bars on edge operating in a 40 c ambient temperature with 50 c temperature rise. Aluminium current carrying is equal to 0 8 times the total volume of the aluminium lenth breath thickness.

Also aluminium has the less current carrying capacity. Is 0 8a per sqmm and copper is 1 6a per sqmm. Apply our equation current carry capacity of 35 sqmm bar 0 8 35 28 amps. For tpn 3 5 x80x10 if we are going with copper.

Aluminum and aluminum steel combinations fig. According to the formula as per iec 62271 i. Bus bar ampacity table ampacities of copper bus bars alloy uns c11000 3 8 x 3 4 281 358 1 09 29 3 1 02 415 1 02 550 1 02 630 3 8 x 1 375 477 1 45 21 9 1 03 510 1 03 680 1 03 790. The current carrying capacity of a busbar is usually determined by the maximum temperature at which the bar is permitted to operate as defined by national and international standards such as british standard bs 159 american standard ansi c37 20 etc.

Suppose we need bus bar for 630a and we are going with aluminium bus bar 80 10 8 640a where 80 10 is size if bus bar usually available is the market. 13 5 m and n. How to calculate aluminium bus bar current carrying capacity. An ampere is a unit that describes the level of electrical current carried by the conductor material.

It turns out that ampacity is a combination of the words ampere and capacity. So we can use 80x10sqmm al. For reference please see ampacities of copper alloy c11000 bus bars or aluminum to copper ampacity comparison chart.