Monument-Solar
Power Management Systems
What do I need to know about power management systems?
The power management system is a critical sub-system of your off-grid system. It handles the transformation, monitoring, and safe transportation of the power you both collect and consume. It includes components like the inverters, converters, charge controllers, bus bars, monitoring devices, shutoffs, wiring and fusing. Without a properly designed power management system, energy can be lost, batteries and other components can be damaged, and cables can melt or ignite on fire. Having a properly designed system is an essential part of building a robust off-grid system.
Continue reading to learn more about the components of a power management system or click the link below to navigate to our store.
Inverters and Converters
DC power is a constant or “direct” form of power. It is the type of power that is stored within the batteries or which comes from the solar panels. AC power intermittent or “Alternating” power and is the power which is fed to the 120 volt outlets within your RV.
But how does the DC power within the batteries turn into AC power at the microwave or air conditioning units? That is where the inverter comes in. This component transforms the power from DC to AC power. This power is then sent to your breaker distribution panel which then feeds the outlets in your RV.
What about charging my batteries using AC power, how does that work? That is where the converter comes into play. The converter will transform the AC power into DC power so that the batteries can store it for later use.
At Monument Solar, we typically use an inverter/converter which encompasses both of these components in one. These come with various rating which should be considered when designing your system. This includes consumable power (both continuous and peak), charging amps, connectivity options, and form factor.
Charge Controllers
Too much power flowing into a system can be harmful to the batteries and other components. This power also may need to be altered so that the voltage is within an appropriate charging range for your battery bank.
So how do we alter that voltage and stop the power from entering the system if it is not needed? This is where the charge controllers come into play. They both change the power to the correct charging voltage of the system and they act as a “gate keeper” who only allows the power to flow into the system when there is a draw on the system or the batteries need power.
These come with two limits which need to be considered. The first is the voltage flowing in. This rating is a hard cutoff and. if exceeded, the component will likely fail and the warranty will be voided. The second is the rated amps which can flow out of the component. This is not a hard limit but it can be viewed as a bottleneck. If the charge controller is rated at 60 amps and you are trying to push 70 amps, you will loose 10 amps of potential power production. This is called “over sizing” your system and is often done with ground mount systems when power in low light conditions is a priority over land utilization. Keep in mind that the amp rating does not change when the system voltage is changed. Because of this, when running a higher voltage system, fewer and/or more affordable charge controllers can be used to handle the power coming into the system.
Shutoffs and Fuses
When an electrical system is built properly and the components never fail, fusing and shutoffs could be considered redundant… but electrical systems do have components that need to be serviced or replaced and there are times when the components or wiring fail. In these situations, it is important to have the proper safe guards in place to keep you safe and your system functioning properly.
Something to keep in mind is that fusing is sized to protect the connections between the components and not necessarily the components themselves. So a fuse will often be rated higher than the potential draw of the component it is feeding.
You also want to be mindful that you are using properly rated shutoffs when using AC and DC power. Some are rated for either AC or DC and others are rated for just one of the two. This is important because using an AC shutoff to cut power to a DC load can cause arching which can lead to the ignition of the unit and a fire.
Having the proper fusing and shutoffs incorporated into your off-grid system will help keep you safe and increase serviceability.
Communication, monitoring, and control
It is important that your off-grid system monitors for errors and reports them to you in a quick and effective manner. It is convenient when that monitoring is unified and robust. To better improve the performance of your system, it is essential to track the performance of the system.
This is where the Cerbo GX, touch screens, bluetooth/cable communication, and sensors come into play. These components work together to provide you with a comprehensive overview of how your system is performing and will notify you when something is not going wrong. In addition to this, when paired with an internet connection, the Cerbo GX allows remote access and monitoring of your system. That way, if your system ever fails or needs the programming changed, doing so can be done remotely by our team.
Cabling
Cables have limits to how many volts and amps that can be safely sent through them. Building a system where the cables are properly sized and rated for their purposes is essential for both the performance of your system and your safety.
Something to keep in mind is that the amp load flowing through the cable will greatly determine the thickness of the cable. This amp load increases as the distance the power has to travel increases. For example, a cable may be rated to handle a given load safely at 5 feet cable length but not at 20 feet. In addition, as the amp limits are pushed with the cables, power will be lost in the form of heat and the system will not run as efficiently.
customization
A Victron electrical system offers a high level of customization to suit various off-grid and mobile power needs. Users can configure components like inverters, solar charge controllers, battery monitors, and smart shunts to match their specific setup. With Victron’s GX devices and the VRM (Victron Remote Management) portal, you can remotely monitor and adjust system performance in real time. Custom settings for charging profiles, load priorities, and generator integration allow for efficient energy use and seamless system control, making it ideal for everything from RVs to full off-grid homes.
important components
2 of the most important components to decide on are you’re inverters and your charge controllers. these are dependent on a few things. for the inverters you need to decide based on the amount of power you will use and need. for a larger system you will need 2 5000W inverters. for small er you might be fine with only 1 5000W inverter or maybe 2 3000W are what you need. the other components you need to decide on are charge controllers those are mainly dependent on how many panels you have on your roof.