Electrical Busbar


Purpose of Electrical Busbar

  1. Provide a common path along the panel so as to limit number of wiring considerably
  2. Easy of maintenance

Types of material using

A. Copper(Cu)

Current carrying Capacity for 1 Sq.mm Cu busbar = 1.6 Amps are mostly considering for the calculation ,its okey even with 1.2,1.4 Amps values as well.




fig : Cu busbar


B. Aluminum (Al)

Current carrying capacity for 1 Sq.mm Al busbar = 0.8 Amps are considered for calculation ,it okey for 0.7 values as well.

Fig : Al busbar

Standard size available on market:

20 x 6 mm
20 x 10 mm
30 x 10 mm

40 x 10 mm

63 x 10mm

80 x 10 mm

100 x 10 mm … etc

Note : Mostly 10 mm width are choosing for power wiring so as to get rigidity
6 mm are using for earthing and Neutral purpose

Example 1 :

          Total load current = 316 Amps

  Cu.BusBar =316/1.6

                =197.5  Sq.mm

Area =Width * Thickness

Width =Area/Thickness

=197.5/10                           Note : Here we took 10 mm for power wiring  

=19.75 mm

19.75 mm approximately equal to 20 mm

i.e,Cu basbar required = Quantity Number∶ Dimension

                                         =  1∶ 20 x 10 mm can bear the 316 Amps load

  For Al busbar =316/0.8

                           =395  Sq.mm

Area=width*thickness

width=Area/Thickness”

=395/10

=39.5 mm

39.5 mm would approximately equal to 40 mm

i.e,Al busbar required=Quantity Number ∶ Dimensions

= 1∶ 40 x 10 mm can be bear a load of 316 Amps


Example 2 :

For Higher Amps ,
Total load current = 1600 Amps

For Al busbar =1600/0.8
= 2000 Sq.mm

Area= width * thickness

width= Area/Thickness
= 2000/10
= 200 mm
= 200/2
= 100 mm

Note : 1. Busbar with size of 200 mm are not available so that 2 number of 100 mm are being used here ,that’s why its divided by 2.Suppose 300 mm is the calculated busbar size then it could be divided into 3 number of 100 mm.

2. Those two busbars are being tightly parallelly connected






For, 1600 Amps Al busbar required = Quantity Number : Dimensions
= 2 : 100 x 10 mm can bear a load of 1600 Amps

Suitable Cu busbar can be implemented as well !

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