What is Busbar? How to do Busbar Calculation?

A busbar is a type of copper or aluminum conductive sheet or rod that collects and distributes electrical energy from one or more circuits. Many connections in various organizations, factories, mill-factory electrical wiring are taken from Busbar.

The bus is drilled with a drill machine and the wire is read and connected through a nut. Just as people use bridges to cross rivers or lakes, they can use electricity and electricity from one system to another.

Electrical substation

In the industry, electricity from the HT side can enter the LT side through this bus connection. Also, if there is an error in any part of the system, the active part can be separated from the faulty part through the busbar. Even if one system shuts down, the work of the other system is driven by the bus.

The standardBusbar features are

The material of the busbar is less resistant
The resistance of the busbar varies very little with the temperature
High mechanical strength.

Use of Busbar

It is very easy to give electricity to one or more places.
Even if one system is turned off, the rest of the system can be run with the help of a busbar.
In the case of maintenance, the other part can be maintained with the help of a busbar without shutting down the entire system.
If there is a fault in any part of the system, that part can be separated from the active part through the busbar.

Busbars are usually of different sizes. Busbars vary in size depending on the load or current capacity. The busbar sheets can usually be up to 1/2 ”, 3/4”, 1 ”, 1.5” or 2 ”wide and the thickness can be 1/6” to 1/2 ”or more depending on the current-carrying capacity.

Basbar needsto have all the features

In the case of a bus, low resistance material should be used.
Resistance will not increase or decrease with temperature and time change.
There should be a sufficient gap between the busbars for insulation as required.
Must use materials with high mechanical strength.
Any future changes to the system will need to be augmented.

Types of Busbar.

Copper Busbar
Aluminum housing

There can also be two types of accommodation depending on the setup. Such as:

Indoor Busbar
Outdoor Busbar

Busbar Calculation

Busbar Calculation: The busbar can be much larger or smaller. How big the busbar is and how thick it is will depend on the current ampere of the busbar. One thing to keep in mind is that height and cross-section are very important in Busbar calculations. Housing measurements need to be calculated in millimeters.

Suppose we have a 450 kVA transformer with a line voltage VL= 400 volts,

If current, I (A) = 1000 × S (kVA) ÷ (√3 × VL) = 1000 × 450 ÷ 1.732 × 400 = 649.519 A 01) then, the total ampere + 25% extra must be taken. (849 amp coming from transformer .. and 649 amp will not be available all the time. It may be more or less so 25% extra has been taken.

Damage if you take fewer buses. No, you have to take 25% more as mentioned above. Does that mean more than 749. If you want to take more, you don’t have to multiply by 0.25, so you have to multiply below 1.25?)

Then, (649.519 x 1.25) = 811.89A
Then the required 812A bus formula
2A = 1mm ^ 1A = 1/2 mm
812A = 406mm ^

Note: It is better to say here that you can hold copper density (1.6 ~ 2) up to 1.8, then you do not need to add an extra 25%. It is better to say here that the height x thickness should be multiplied by 406mm.
Now we can take 80 × 5 = 400.

Busbar size:

Size	Amps
19.05 MM × 6.35MM	100A
25.4MM × 6.5MM	200A / 250A
30MM × 10MM	400A
40MM × 10MM	600A
44.45MM12.7MM	800A
50.8MM × 12.7MM	1000A
2 × 63.5MM × 9.525MM	1600A
2 × 80MM × 10MM	2500A

Busbar Calculation 2

Suppose I have an 11/44 KV transformer of three-phase 500KVA in my industry. Now I will select the busbar for the current of its outgoing side which I will set up in my LT panel. Let’s calculate.

Current I (secondary)
= 500 x 1000 (1.732 x 440)
= 656 Ampere

Now for added security, I need to add 25% extra. So = 656 x1.25 = 820 A Now if I use a copper busbar, 0.5 sqm busbar should be used for every 1A. And 1.2 sqmm per ampere for aluminum.

So if I use copper, I should use a 410 sqmm busbars for 820amps load. But you have to keep an eye on whether this accurate size housing is available in the market ??

The sizesthat are usually available in the market

25 x 5, 25 x 8, 25 x 10, 30 x 5, 30 x 8, 30 x 10, 40 x 5, 40 x 8, 50 x 5, 50 x 8, 50 x 10, 80 x 5, 80 x 8, 80 x 10, 100 x 20, 110 x 10 sqmm etc so for our load 80 x 5 or 40 x 10 or 50 x 8 sqmm busbar is enough

What is Busbar? How to do Busbar Calculation?