Busbars, although simple-looking pieces of copper and aluminum, serve a more specific function. They have holes, slots, bends, cut-outs, and offsets added to make the busbars capable of meeting specific electrical, mechanical, or assembly requirements.
Depending on the electrical cabinets, switchgear, EV battery pack, or energy storage systems, the design of the busbars provides information about its fitting and function in the assembly. Therefore, in order to design the best busbars, it is essential to understand what role each of the components plays.
Why do busbars have holes?
Holes are perhaps the biggest common feature found in copper and aluminum busbars. Holes are made to ensure that the busbars and other conductive contact points can be joined together using bolts.
Holes are, for instance, used to make a connection between busbars and:
- Terminals or electrical studs
- Busbars
- Switchgear equipment
- Cable lugs
- Battery terminals
- Power distribution connections
Hole orientation and size are chosen carefully. They must meet the specifications for the fastener being used, terminal geometry, clearance needs, and assembly method.
Hole spacing must also be considered. Any deviation of even 1% in the dimensions involved can make it impossible to do the installation.
What Can Slots Be Used For?
Slots serve a purpose of providing flexibility that round holes could not achieve. A long slot allows for some movement at the time of assembly when the position of the mating piece could vary. Slots can also be beneficial in situations when it is necessary to fit the busbar into a certain mounting/positioning consideration. Nevertheless, implementing a slot just because it offers flexibility is sometimes not a right design decision. The dimensions, directions, distance to edges, and surrounding material should be carefully evaluated.
It is important that in the case of drawing-supported manufacturing the above-mentioned characteristics are clearly specified for making sure the final product is obtained correctly.
What Is The Importance Of Bending Busbars?
Bending busbars is important in the electrical system layout of the components in the circuit, as it allows the busbars to fit the system layout. There are several reasons for the use of bent busbars.
- change the height of connection points
- Avoid the intrusion of other components.
- Follow the compact design of devices.
- Establish connections between terminals located at different heights.
- effectively utilize the available area
- Protect the circuitry from other objects.
Such processes are especially relevant for compact devices and battery packs that have different components placed in limited space.
When making a bent busbar, many parameters must be taken into account, such as the angle of bending, place of bending, internal circle diameter, and metal thickness. The change of position of the bent section might worsen the whole structure of the busbar.
Holes, Slots, and Bends Must Be Designed Together
It is important to consider the busbar features as a group.
Take, for example, a busbar with two mounting holes separated by a 90-degree curve. Moving the curve by a few millimeters can result in moving one connection point. Similarly, the thickness of the material may influence the geometry of the shape created.
Thus, custom copper and aluminum busbars are generally manufactured according to application-specific drawings rather than a single shape standard.
For battery applications, busbar geometry is especially important because a busbar can be formed in such a way that it matches the position of the terminals of the cells.
For complex designs involving holes, slots, bends, and specific tolerances, Adinath Enterprises manufactures busbars as per custom drawings, allowing the required geometry to be defined according to the application's physical and electrical requirements.
Manufacturing Considerations
Manufacturing is necessary once the design is approved. This step involves the reproduction of the desired shape.
Standard manufacturing operations include precise cutting and drilling, punching and bending, and designing and finishing.
All the vital measurements should be indicated on the drawing, including hole diameter, hole spacing, overall dimensions, bending position, angle, thickness, and other tolerances.
All the sharp edges and burrs should be eliminated, since they can cause problems during the assembly or can interfere with insulation.
There might be cases in which surface finishing is conducted based on how connections are made, such as in applications where copper busbars are plated with tin or nickel.
Common Busbar Design Mistakes
There are a number of typical issues that can be avoided at the very beginning:
- Incorrect positioning of holes
- Inability to adjust slots
- Too close bends in reference to the holes
- Insufficient distance from neighboring elements
- Poorly defined parameters
- Sharp edges after punching and cutting
- Designing busbars without considering assembly issues in the project
A great drawing should show not only the busbar size but also some relevant features.
Practical Design Methodology
Go with electrical connections and installations as part of your design process. The next step is to determine the material, the thickness, the hole pattern, the slots, the bends, the clearances, and the tolerances.
Testing the prototype against the actual mating parts will help identify potential issues before commencing regular production.
Final Thoughts
Holes are the anchor points, while slots allow adjustments, and bends give the busbars the opportunity to comply with complicated physical designs. Each point has a unique functionality, and it is important to consider all requirements concerning the electrical, mechanical, production, and assembly processes in the development of any product.
In order to eliminate unanticipated problems, it is appropriate for engineers and producers to treat busbar geometry as the functionality of the system rather than just a metal piece.