Busbars are made up of highly electrically conductive metals and they distribute & carry power from a source to a destination or multiple destinations.
What are Busbars?
Busbars are made up of highly electrically conductive sheet metal and they distribute and carry power
from source to a destination or multiple destinations. They can be used in all kinds of Factories,
Buildings, Malls, Airports etc.
Busbars come in a variety of configurations, shapes, sizes, materials and current carrying capacity.
When you need to conduct a significant amount of current, busbars are your best bet.
For example, if you want to power many of your heavy duty cranes in one bay, you use a system of busbars.
The efficiency of a busbar will depend upon the Ratio of the Input Power to the Power Output.
In Low Power Systems Such as a ‘pcb’ in a household or industrial appliance,the ground or Power plane can be thought of as a bus bar.Current in these low power systems tend to be in the milli ampere range.
In High Power Systems, where you have to transfer 1000 Amperes of Current through a three phase busbar system, it is a different game. The design, Installation, Safety during such an installation become critical factors.
What is the Need for Busbars?
They are a very efficient system to carry significant amounts of current between different electrical subsystems.
Where are Busbars used?
A busbar is not the only solution to deliver power to your machinery but it can be used in many different configurations.
What is the Current carrying capacity of Busbars?
The Current carrying capacity of the busbar are highly dependent on the operating temperature. In an Industrial environment, most of the heat lost by the busbar will be due to Convection. Current carrying capacity of a busbar can range from 1 Ampere to 1200 Amperes.
40 Ampere Busbar
60 Ampere Busbar
100 Ampere Busbar
140 Ampere Busbar
200 Ampere Busbar
250 Ampere Busbar
300 Ampere Busbar
400 Ampere Busbar
500 Ampere Busbar
600 Ampere Busbar
700 Ampere Busbar
800 Ampere Busbar
900 Ampere Busbar
1000 Ampere Busbar
1200 Ampere Busbar
Does the Resistance of a Busbar Matter?
Yes, it matters.
Heat generated by the busbar = I2R
Where I = Current Carried By the Busbar
R = Resistance of the busbar
Increase in resistance of the busbar, produces more heat which in turn reduces the total power efficiency of the busbar system decreases.
Which Busbar Should I choose for my application?
- – Energy Efficiency Required
- – Current Carrying Capacity Required
- – Life Time Cost
- – Length of Busbar Installation
- – Maintenance Procedures of Different Busbars
- – Cooling Method Provided to the Busbar
- – Inductance & Capacitance of Longer Busbars
- – Space Constraints
- – Cost Constraints
Used in corrosive atmosphere, chemical plants, 60 Amps in W type.
Let's go through the important technical parameters of Iron as a metal:
Melting point of Iron: 1538 °C
Boiling Point of Iron: 2862 °C
Density of Iron: 7.874 g/cm 3
Electrical Resistivity of Iron: 96.1 nΩm
Applications of Iron Busbars are in trolleys, over head cranes, hoists.
Let's go through the important technical parameters of Aluminium as a metal:
Melting point of Aluminium: 660.32 °C
Boiling Point of Aluminium: 2470 °C
Density of Aluminium: 2.7 g/cm 3
Electrical Resistivity of Aluminium: 26.5 nΩm
Properties of Aluminium:
Aluminium is ready available because it makes up almost 10 percent of the earths’ crust. Aluminium has
almost 33% density of copper or Steel. When exposed to air, aluminiums’ outer layer oxidizes and helps in
making aluminium excellent at corrosion resistance and hence aluminium maintains a good silvery finish at
Aluminium is a good material for busbars because of its very High electrical and thermal conductivity, low Density, excellent corrosion resistance and high mechanical strength.
Aluminium busbars are cheaper than copper busbars but offer about 60 % of coppers electrical conductivity. Aluminium also weighs almost half of copper busbars. Since Aluminium is a soft metal, Aluminium busbars can be made with the help of rolling machines or extrusion machines.
First lets go through the important technical parameters of Copper as a metal:
Melting point of Copper: 1082 Degrees
Boiling Point of Copper: 2564 Degrees
Density of Copper: 8.96 g/cm 3
Electrical Resistivity of Copper: 16.78 nΩMeter
Since Copper is malleable and Ductile it can be formed into many different kinds of shapes. It also has a high thermal conductivity to spread out the heat evenly. Due to all these parameters, copper is the most favoured material to be used in Busbars.
Copper Busbars are much superior to aluminium busbars in terms of conductivity but the trade off here is cost and weight. Since the density of copper is high, it is more robust to external mechanical disturbances and damage.
Copper Busbars will transfer significant amounts of current, hence, there will be a small percentage of power lost in transmission and converted into heat. This heat will be lost to the external environment through convection and radiation.
Cost Comparison of Busbars For Overhead Cranes
Electrical performance of Busbars for Overhead Cranes
Different types of Joints for Busbars
Bolt Type Joint
Pin Type Joint
Weld Type Joint
Rivet Type Joint
Protection from Short Circuits
In a three phase power delivery system, a minimum of three parallel busbars will be used to deliver power to the crane machinery. The gap between the busbars is an important parameter to avoid short circuits.
If there is a short circuit, the current will rise until the protection device kicks in. This very high current will heat the busbars and will cause mechanical stress to the busbar as well as its support units.
Protection from Human Touch
We only recommend insulated busbars, because like every other
electrical circuit, busbars need to be protection from human touch. No live or HOT sections are exposed
to the external environment.
Safe distance should also be maintained between two parallel busbars. Insulation will also help in prevention of short circuit in the presence of foreign material touching two busbars.
Lifetime cost of Busbar
The design of the electrical system will play a major role in the installation price. The design of installation should focus on minimizing the time required to install the busbar and all its supporting components ,should minimize maintenance time,should provide easy and safe access to the maintenance and installation personnel. A well designed electrical system ,will allow for connections and disconnections in the future without stopping the production of a factory. The design should also allow for extensions to the busbar if required.
Cost of Installation
Cost to erect the busbar to the particular height, complexity of the busbar installation. Time to install all the number of supporting components such as joints, brackets,pins,etc play a major role in installation cost.
Maintenance cost of a busbar will be reduced if the busbar is used correctly. Using the busbar at lower working temperatures and not overstressing the busbars will cause the busbars to increase their life and reduce the maintenance costs.
The amount of voltage drop in a busbar will affect the cost of energy you pay . Selecting the right conductor size will greatly minimize the voltage drop.As the weight of material increases the cost of the busbar increases, and the cost of energy decreases.
End of Life Cost
At the End of Life of the system, the busbars and its supporting components have to be removed.The cost of material used for the busbars will be of significant value. As the cost of metal increases the cost of material used for the busbar might appreciate. All other supporting plastic components will have to be recycled.Keeping all these points in mind, you can get a very practical view of the overall cost of a busbar system.