Backfeed an Electrical Panel with a Generator (Explained)

When the power goes out within your home, you will want a generator to keep electricity working, even the bare minimum. 

However, sometimes you might need appliances to work continuously, like the refrigerator or doing laundry. In that case, you find a term called “back feeding.” Well, what is it, and how does it work?

Backfeeding is the movement of electric power in the opposite direction to that usually assumed or conventional. This reverse flow might be intentional or unintentional, depending on the source of power.

Backfeeding can lead to unanticipated problems for electrical grid equipment and service personnel if it is not avoided (in the case of unintentional back feeding) or carried out correctly (in the case of intentional back feeding).

Backfeeding with a generator is how you power your house in the event of an outage. A generator located outside connects to your home through a backfeed cable plugged into a 240-volt outlet. When done correctly (with a bypass switch) backfeeding is safe.

Attempting to backfeed without a transfer switch can cause electric power to flow in reverse through the utility service, causing damage to the electrical grid, or worse, killing a lineman working to restore power.

This article speaks on many subjects about backfeeding, like how it works and some severe repercussions for doing this method. 

After all, working on anything dealing with electricity, especially a DIY scenario, can potentially cause a risk. In that case, keep reading to find out all there is to know on backfeeding! 

What is a Breaker Panel?

Firstly, it is essential to know what a breaker panel is to gain more knowledge.

Simply put, a breaker panel is what controls the entire electricity from within your home. It contains multiple wires on a board that divides up electricity within the home. 

The panel also has a fuse protector for every circuit within a specific vicinity, meaning that if you use too much power, a portion within your home goes out, making you have to go down to where the panel is to reset the circuit breaker.

Although a breaker panel is often called that name, many other names get taken into account, so it is not a one-size-fits-all when it comes to the word. These words are as follows;

  • Electric panel
  • Panelboard
  • Distribution board
  • DB board
  • DB box 

Moving along with how a breaker box works, it has two columns on either side in the USA. The numbers run left to right going from the top to the bottom. Overall, the numbering system is universal with many different brands.

Other electric panels involve using an A, B, and C for the rows instead of two columns, allowing two or three trip breakers. In return, each phase will get a pole. 

In North America, you will have a wire going line to line for large equipment perpetually installed there, taking up 2-pole or 3-slots in the panel. 

The panel uses 3-phrase power and 208 voltage, and each split-phase electric power uses 240 voltages.

What is Backfeeding an Electrical Panel with a Generator?

As you already know, when the electricity goes into your home, you are powering all of your appliances, lighting your home, and using the outlets as a power source to charge everything you desire (phones, TVs, tablets, etc.)

When backfeeding, electricity from a generator flows from the house back through the power grid, damaging the power grid or killing linesmen working on power outages.

A generator connects to the house through a backfeed cable connected to a 240-volt exterior outlet. To prevent backfeeding, a transfer switch is needed, which shuts off the power flow to the meter base and out to the power grid.

Without a transfer switch, the electric power the generator creates passes through the main breaker and back to the meter base panel, to the transformer, and then energizing utility lines from within your neighborhood. 

To prevent backfeeding the public grid, a transfer switch is critical to bypass the meter base. It’s best to call a licensed electrician to install a transfer switch before connecting a generator.

As you can tell in the video above, when people backfeed their homes, they will make a backfeed cord with 2-male plugs connected to the generator. Electricity enters the main breaker by the branch circuit breaker of the outlet. 

It should be relatively easy if you have ever replaced an end on an extension cord. However, the cables are much larger and challenging to work with. 

Make sure to strip them down like usual, take apart the male end of the plug then make the connections. Make sure the red and black cords are on either side, the ground is at the top, and white on the bottom.

Note: If you do not know what you are doing for plugs, do not do it. It is better to be safe than sorry.

What Risks Are Involved with Back Feeding?

It is crucial to know what you are getting yourself into when dealing with anything electrical. 

1. You Have a Lack of Experience

Many people try to do things within their homes, including electrical work or projects requiring a permit. 

Although some DIY projects are reasonable, such as making furniture or other tasks, some things need to be left to the professionals. 

In this case, having a professional come and help you with correctly installing the generator hookups is best to ensure it’s done correctly. 

2. It is Illegal in Many Places

Not only is it not for inexperienced people, but when you deal with utility lines and electrifying them to get what you desire, back feeding is illegal in many states, countries, and neighborhoods. 

If you are unsure about the legalities within your area, make sure to look it up. 

It is illegal because it can potentially cause death, injury, and property damage.

On top of that, backfeeding can pose a severe threat to utility workers who work on the line year-round. 

If they get injured or killed due to your back feeding, it is a liability issue, and you may be charged with criminal prosecution. 

Suppose your Internet goes out, which happens more frequently in certain areas than others. 

In that case, someone who works on the line may get severely injured with the energy surging through the utility lines through the neighborhood. 

3. Disconnection of Power of Fines Charged

Furthermore, even not injuring someone has its consequences too. These consequences include multiple fines or the utility company disconnecting power from your home. 

Keep in mind that 240 volts of power can quickly kill someone instantly. It is not a question of whether you can do it, but if you’re willing to risk yourself and others for something that you can easily avoid. 

If you wish to reduce the risk of this happening, you must shut the main breaker off. However, it is essential to know that there is no 100% guarantee against any threats involved. 

4. Tripping Over the Backfeed Cable

Leading to our next point, if someone happened to stumble or trip over the backfeed cable, it could pull loose, leading to electrocution for that person. Sometimes the breaker back feed cord is called a “suicide cord.”

Say you live with an older person, have young children, or even have little furry friends wandering around. If it is dark or someone is not paying attention, this can be a massive risk factor. 

5. Not Being Able to Balance the Loads

Lastly, the electric panel gets electricity from the generator, which powers the entire home when you are backfeeding. However, a large portable generator has limitations to its output. Running too many circuits can cause a significant voltage drop leading to unbalancing the loads.

Given that information, a generator can supply 240 volts of energy between 2-lines of 120 voltages, meaning each line delivers half the generator’s capacity. The more circuits you run, the more unbalanced the load becomes.

Why Do People Backfeed if it is Illegal?

Since we now know that back feeding is illegal in many places, why do people still do it? What is the point?

People backfeed because it puts energy into the power outlets during a power outage, giving people electricity to run their appliances.

For example, if there is a massive storm in the area, and all households get out of power after you just went grocery shopping, then those perishable items are at risk. 

Another example to backfeed is so that you can continue to cook your dinner or do all that pile of laundry you have neglected for a week straight.

Some Solutions for Back Feeding

Not everyone will want to back feed their homes due to not wanting to risk the safety of themselves or others within the home or surrounding them. In that case, there are a few solutions you can use for 

1. Washing Machine Solution

When it comes to washing your clothes, you can purchase a manual washing machine, like this one, which is extremely easy to use. 

Not only is it good to use a generator for emergency preparedness, but you can use a manual washing machine for RV’s, camping, small apartments, and dorm rooms. 

After the cycle finishes, air-drying your clothes might be the best choice.

2. Cooking Option

An excellent option for cooking is to have a camping stove within your home, so you do not need to worry about electricity. 

3. Refrigerator 

Perishable items are a little more tricky. Unless you have a massive tub of dry ice, the best option may be not to open the fridge or put refrigerated items inside a giant freezer until the electricity comes back on. 

What Are the Different Kinds of Backfeeding?

There are a few different types of backfeeding that you should know about. These are:

  • Intentional
  • Unintentional 
  • Intrinsic 

1. Intentional Backfeeding

Over the last few years, many commercial products have finally made their way to individuals wishing to purchase them for their homes. 

Great examples of the demand for commercial products are wind turbines and solar panels. In that case, generated electrical power is no exception.

During excellent power-generating conditions, a generator is required. If the electric utility provider cannot support more power generation, the power grid systems get fed with electrical power. A utility meter shows how much energy you have consumed.

Due to backfeeding, the power generator gets used for a short time, and electricity stays in reverse mode as long as the generator is on. 

2. Unintentional Back Feeding

Many homeowners or consumers may not realize they are backfeeding, which can be unintentional. It typically happens when the portable generator is in use and incorrectly plugged in. 

When a power outage happens, and a homeowner needs to power the home to use their appliances, the energy then flows over the electrical power lines in a reverse direction, which re-energizes it. 

However, plugging the generator directly into an appliance outlet within their homes can cause a significant issue. Although your appliances are powered up, electricity flows back into the power lines, and you are taking a risk. 

3. Intrinsic Backfeeding

Lastly, we will discuss intrinsic back feeding, where the generator does not produce more electrical power than it can handle. The generator then becomes the consumer. 

It is commonly shown when the generator shuts down or operates at a smaller capacity. The parasitic load (or power consumed when the appliance shuts down) is greater than the generator power. 

When there is a power outage, the generator needs to continue supplying power to appliances and other systems to stay active with standby power or with a power unit of their own. These appliances include pumps, lighting, HVAC systems, etc.

Given that information, when the power has more than what the commercial generator has, then intrinsic backfeeding occurs. 

However, if you wish to reduce this and increase efficiency, then make sure to keep the electrical utilities on standby power or reduce the parasitic load.

How to Stop Your Generator from Backfeeding?

You can use a transfer switch to stop your portable generator from backfeeding to the power lines. Without a transfer switch, things can spin out of control relatively quickly. 

A transfer switch will flip the switch manually on and off, isolating the home’s electrical system from the utility lines. 

Not only is this the safest option, but the switch itself allows electric power through specific circuits within your home. 

Can You Backfeed an Electrical Panel with a Generator? (The Best Solution)

According to the National Electric Code [700.5(B) and 701.5(B)], emergency systems have to provide a means to bypass and isolate transfer equipment. In this case, it is safest to provide a transfer switch to use the generator. 

It is not required, but the provision is allowed. It depends on several engineering decisions and operational parameters whether you use this or not. 

Connecting a generator to the breaker box is safer if you have an outage. Because of this, you need to wire it through a manual or automatic backfeeder breaker or manually transfer the switch with an interlock. 

A manual transfer switch is not available for portable generators, whereas most other generators have this option. In that case, you will need to connect the transfer switch yourself. 

You will not need an extension cord after the transfer switch is appropriately installed because the home’s circuits can be directly connected to the portable generator.

How to Determine the Manual Transfer Switch Size

To determine which size you need the transfer switch to be, you need to look at the maximum current in amps. Typically, you will find that the sizes for residential use range from 30 to 200 amps. 

Figuring out what size you need is relatively easy. Make sure to chart the home appliances that have to be used during an outage (washing machine, fridge, oven, etc.). 

Afterward, add up the total numbers, and you’ll have the size of the amp. If you need more help, ask an electrician or someone you know who has definite knowledge.

Conclusion

To conclude everything, backfeeding redistributes electricity inside your home by moving the power backward. A generator then connects inside your home, which reverses powering it up and attaches the generator to any appliance.

However, whether it is safe or not is a different question. Although many homeowners insist on this happening, it may not be the wisest choice to make. Make sure to ask yourself all the safety questions before doing something you might regret.

Sources

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Hubert Miles

I've been conducting home inspections for 17 years. I'm a licensed Home Inspector, Certified Master Inspector (CMI), and FHA 203k Consultant. I started HomeInspectionInsider.com to help people better understand the home inspection process and answer questions about homeownership and home maintenance.
DISCLAIMER: The content published on HomeInspectionInsider.com is not professional advice. You should consult with a licensed professional and check local permit requirements before starting any project.
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