Fuse Between Battery And Inverter (Do This)

Fuses are an integral and essential component in most electrical installations, and they play a vital safety role. The ensure that any excessive current traveling through the wire that could damage the system does not reach critical equipment.

You would need a fuse between the battery and the inverter. This protects the wire and the inverter from overload, potential damage, and fire. Depending on the size inverter you have, you will require different fuses, like 12V, 24V, and 48V inverters would require different size fuses.

To get a better understanding of why you would need a fuse between a battery and inverter, we need to understand the following:

  • What function fuses perform between the battery and inverter
  • How to determine what size fuse you would need for your inverter
  • What happens to the inverter when a fuse blows

Understanding how and why fuses work and why they should always be installed between the battery and the inverter regardless of the inverter size will give you the information you need to ensure your inverter system is protected.

Solar Fuses On A Wall
Solar Fuses On A Wall

What Does A Fuse Do Between The Battery And Inverter?

The fuse connected between the battery and the inverter will protect the inverter and the wiring from a power surge or short circuit damage.

A fuse connected between the battery and the inverter is probably the most critical fuse of all, as this is where the most current would be flowing in the system. There are often other fuses within the system, and most inverters have a built-in fuse.

The current generation in a PV system can fluctuate, and the fuse between the battery and the inverter will protect the inverter and the wire in the event of a power surge.

The Function Of A Fuse In A Circuit

Fuses and circuit breakers are designed to fulfill a single purpose: to prevent overheating and damage caused by short circuits or current surges to the connected electrical equipment.

You find fuses in almost every electrical device, from your car to home electronics. They are an essential safety feature, whether installed in the device itself like an amplifier or between electrical power sources and the distribution devices like a power inverter.

Connection Load

A fuse works by having a specific current rating. If that current maximum is exceeded, the fuse will blow and prevent the higher electrical energy from traveling through the wire and reaching the connected load.

The fuse will blow when the fuse element overheats due to excessive current, and this causes the element to melt and break the current flow between the battery and the inverter.

While some people view blown fuses as an inconvenience, they are, in fact, critical indicators of a problem in the circuit.

If they are blowing consistently, that signals that an investigation into the issue is warranted.

What Size Fuse Would You Need For Your Inverter?

The size of the inverter you have and what voltage the inverter is running will determine the size of the fuse your system will require.

The general rule when it comes to sizing fuses is to use the following formula:

Continuous Wattage / Battery Voltage X 1.25. The 1.25 is a safety factor incorporated, so your fuse can handle slightly more than the capacity but not too much over-capacity to cause damage in short or surge.

As an example:

  • If your inverter is rated at 2000W and your battery bank is 12v, the equation would be as follows:
  • 2000W/12V = 167A X 1.25 = 208 Amp, so a 220A /250A fuse would be recommended in for this system.

The Importance Of Cable Thickness

Another factor when calculating what size fuse you would need is the thickness or gauge of the cable that will connect the battery and the inverter. This is also dependent on the inverter’s wattage and the battery voltage.

Remember that the thinner the cable, the lower the fuse has to be, as the cable will not be able to accommodate a higher current running through it without overheating or burning.

When establishing what size fuse you need, use the correct gauge cable to match the current requirements, and your supplier or manufacturer will be able to advise on this.

What If Your Fuse Between The Battery And Inverter Blows?

If your inverter is running connected load appliances, when the fuse between the battery and the inverter blows, all connected devices will stop working immediately. There is no risk of damage to the connected load if this happens.

The inverter will shut down as the current flow is broken, and to restore the electrical current, the fuse will have to be replaced to restore the current flow.

When replacing the fuse, switch the inverter off or disconnect the load so you don’t create a power surge when reconnecting the fuse and circuit.

Remember that if you have appliances connected that require a start-up load like air conditioners or fridges, it is better to reconnect them one at a time.

Power Surge

A power surge will occur when the connected load draws more than the inverter’s rated power, and this can cause the fuse to fail again as it protects the inverter from over-demand as would save the connected load from too much current flowing to it.

Suppose it happens that your fuse is constantly blowing. In that case, you need to check the connected load devices for short circuits or see whether you have connected another appliance that may be overloading the circuit and causing the fuse to blow.

Another cause is that the inverter itself may have developed a fault. You can quickly check this by disconnecting all the connected devices and then switching the inverter on.

If it still trips or blows a fuse, there is an issue with the inverter itself, and your supplier or manufacturer should check it.

If the inverter checks out, you need to check the batteries to ensure that they are charged and discharging the correct voltage and current.

Always check the wiring to ensure that the connections are tight on the battery terminals and the inverter connections.

Resources

General Solar Panel FAQ

What Problems Do Solar Panels Solve?

In environmental terms, solar panels can potentially solve a handful of problems, including;
1. Air pollution
2. Water pollution
3. Greenhouse gases
4. Reduction in fossil fuel use

For individuals, solar energy allows you to become completely self-sufficient when it comes to your electricity needs and can save you a lot of money in the long run.

What Are 3 Important Uses Of Solar Panels?

The three most important uses of solar panels are;
1. Solar electricity. This can be used to power almost any appliance in your home, including TVs, computers, and fridges.
2. Lighting. In addition to the use of low-power, LED lightbulbs, solar panels can provide an efficient, low-cost, and environmentally friendly way to provide lighting to homes. 
3. Portable solar. In our modern, always-connected lives, our phones, tablets, and computers are almost always with us, and all run on batteries. Portable PV chargers can help keep our batteries topped up no matter where we are, as long as there is some sun to charge them.

Do solar panels give you free electricity?

Once the cost of the array is paid in full, the energy it produces is free. There are ongoing maintenance costs, too, such as annual panel cleaning, etc. 

How much will my electric bill be with solar panels?

Suppose your solar array includes a solar battery backup system, and it is large enough to fully cover your energy usage per day. In that case, your monthly electric bill will be next to zero dollars, even with a grid-tied system. 

If your solar array does not include a solar battery backup system, then at night, your house or business will use grid electricity. That cost will vary but expect to pay from 1/3-2/3 of your average electric bill, and that cost will fluctuate seasonally. 

Do you save money with solar panels?

The simple answer is, Yes, you save money with solar panels. There is an initial upfront cost, but since solar panels are warrantied for 25 years, you will save money over time. You will also begin to see monthly savings in energy bills, but there are other ways that solar panels pay you back. Those include:
1. Adding value to your home or commercial building 
2. Monthly decreases in energy costs
3. The ability to add more energy appliances without increased monthly costs
4. The potential for tax credits for going solar

Can solar panels power a house 24-7?

Most definitely! Solar panels can certainly power a house 24-7, with the addition of a high-quality inverter and a suitable battery bank, of course. To power, a house under normal usage will require a massive solar array, though, and there will be a very expensive initial financial outlay.

Do I need to tell my energy supplier I have solar panels?

This depends on where you live, but in most cases, it’s not necessary to inform your energy supplier that you have solar panels. That said, you may be producing excess power with your solar system, in which case you may be able to sell that excess power back to energy companies.

In this case, you’ll naturally need to be in contact with them. 

What Are Solar Cells Known as and Why?

Solar cells are also called photovoltaic (PV) cells. They are called so because the term ‘photovoltaic’ literally means light i.e. photo and electricity i.e. voltaic.

These cells generate electricity through the photovoltaic effect. This effect basically causes the generation of free electrons from the semiconducting silicon material of the solar panel when sunlight hits its surface.

What Type of Solar Panels Are Most Efficient and Why?

There are currently three types of solar panels available in the market that are:
1. Monocrystalline
2. Polycrystalline
3. Thin-filmed

Among these, monocrystalline solar panels are known to be the most efficient among all others.

Does heat enter your home through the roof?

Absolutely. Heat enters your home through your roof, and on a hot day your attic can get up to 150 degrees Fahrenheit or more. Through conduction, heat from the sun warms your roof which then warms your attic and the rest of your home.

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