What Are Busbars?
Bus bars (often called bus bars) are thick metal strips that connect various circuits to power or ground points. They are often used in electrical distribution systems (not just campers) to help transmit electricity efficiently. Rather than connecting every circuit directly to the battery, it’s easier to install the bus bars to the battery posts. Each circuit is then connected to a bus bar instead of a battery, making maintenance, installation, and future expansion easier. Because they act as an extension of the battery terminals, electrical systems may have positive and negative bus bars.
The higher the conductivity of the busbar, the more efficient it will work. Therefore, industry-standard bus bars are made of copper. You can find aluminum and even brass bus bars, but we recommend avoiding them as they are less efficient. Most busbar system is coated to protect the copper from oxidation and corrosion, usually tin.
What are the busbars used in camper refits, RVS, and motorhomes?
A camper’s recreational battery pack may be hidden under the bed, front seat, or cupboard. The vehicle’s grounding point may also be located under the driver’s seat. This makes them difficult to access for installation, maintenance and future expansion. The busbar is installed in an easily accessible location inside the camper. There’s no need to remove the driver’s seat or crawl under the platform bed, and you can access the system more easily with conveniently positioned bus bars.
Do I need a busbar in my camper?
The most concise answer is no. The traditional way to install a DC system is to connect the end of each circuit directly to the positive terminal of the battery pack (or, more likely, the battery disconnect switch) and ground. Even if you decide to use busbars, you don’t need to use both negative and positive busbars. Instead, you can use one or the other.
Advantages and disadvantages of using busbars
Bus bars have several benefits, especially for simplifying electrical installation in camper van conversions.
- Improved Accessibility: Vehicle manufacturers decide where to place earth spots, and their choices rarely take into account the RV owner or DIY camper manufacturer. Also, battery packs are often large, and for everyday life, the best location is out of the way. But of course, this doesn’t help when adding new circuits or initial installations. Bus bars allow you to overcome these inconveniences by installing them in the location that works best for you – most likely in your dedicated electrical cabinet.
- Easier to meet local regulations: Some regulations specify a maximum number of connections per stud. For example, ABYC regulations state that there should be no more than four connections on any terminal. This is a tough requirement for anything but small systems, so using a busbar system will allow you to comply with the strictest regulations.
- More circuits: In the absence of bus bars, the number of connections that can be added to a terminal is limited by the length of the binding posts. With busbars, you can simply add another busbar if you run out of termination points or risk exceeding the maximum continuous current rating.
- Improved Scalability: Busbars can be easily expanded to more circuits. Just connect the circuit to any available binding post (or screw) on the busbar and you’re done. If no studs are available, you can add another busbar quickly and efficiently at a relatively low cost.
The only real downside to using a properly installed busbar is the cost of additional components compared to the more traditional method of configuring a 12-volt wiring system using only a fuse box. The busbar configuration requires all the same components as well as the busbars.
However, the cost may be offset by the difference in cable cost. Without bus bars, each circuit would require a length of cable between the fuse box and the battery disconnect switch. This is usually a small cable and usually costs less per meter than thicker cables. When using a busbar configuration, you will need a larger cable depending on the distance between the battery and the ground point it is mounted on. But since you only need one length, it may cost less.
How are the busbars rated?
Some electrical regulators provide general guidance on busbar ratings, and they focus on the ambient temperature at the operating location. However, many unbranded busbars apparently meet these guidelines but are known to melt. This is a recipe for disaster in any environment, let alone your camper. High-end busbar brands go far beyond these guidelines. For example, Blue Sea busbars have a larger cross-sectional surface area at the same amp rating as some unbranded competitors, so they are more efficient at cooling. This is one of the reasons why we recommend always using high-end components.