Can you Plug a Generator into a Wall Socket?
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If you plug the generator into the wall socket, it may result in back feeding (or electrical current flowing in the wrong direction). The workers that are fixing an outage problem could get hurt or killed, this is why it is also illegal. Using a suicide cord is extremely dangerous as well!
Since there is no breaker on a typical wall socket, you are also risking your house catching on fire and if you forget to turn the main breaker off, your generator could catch on fire when electricity is restored.
The problem with undersized wires that could melt and cause shorts should not be overlooked as well. Doing it right (with a transfer switch) is the best option and the work should be done by a professional only!
Sorry, there is no quick and cheap way around it. Feel free to read this article on connecting a generator to a control panel WITHOUT transfer switch and ways to do it.
So, what are the risks associated with connecting your generator into the wall socket? Here are some reasons why you should NOT do so:
- You can kill a power line worker. Any engineer working on the main power lines is at risk of getting electrocuted as the generator power (without proper transfer switch installation) is being backfed into the grid. This is a life-threatening situation and isn’t something you want to be held accountable for.
- You can damage your neighbor’s property or cause harm. Since they are technically on the same utility transformer as you, they will get their “doze” of backfed power. Uncontrolled power, on their end, could damage some appliances or cause an electrical shock.
- Your home’s electrical system and appliances may get damaged. Without a breaker, nothing will stop the current from melting your wires in case the wire size is too small (and it probably is). If your wiring shorts, as a result, you are risking frying your appliances.
- It’s a fire hazard situation. Since no breakers will stop the generator from producing power and home electrical wires are not large enough to handle generator power, overheating inside your home electrical system may cause a fire. Yes, I know, generators have breakers. But there are cases that generators did not respond quickly enough and why would you risk something like that?
- The generator can blow up. Yes, this seems extreme (and dangerous), but it does happen. Here is a more detailed article on this one. The moral of the story is that the guy forgot to turn off the main circuit breaker and as the power came back, it was fed back to the generator (and in this case, it fried it, with blow up as a result).
- It’s illegal and for a good reason! You should also be aware that plugging a generator into a wall socket is prohibited by law and you can read about it in US National Electric Code. If you decide to do go ahead and do it anyway, you will be held liable for your actions. Here is some explanation of electrical codes.
- It is highly likely that your homeowner’s insurance will NOT cover the damages that result from backfeeding. What this means for you? Besides being in the situation where you are gambling with a law, you will have to pay all the repairs out of your own pocket if something happens.
You should NEVER connect a generator to a house electrical outlet. Also, it should NOT be connected to a circuit breaker panel without an automatic or manual transfer switch (also known as a two-way transfer switch).
Installation of your generator should be done according to the National Electric Code (700.6 and 702.6). This is why only qualified electricians with code knowledge should be installing your generator.
For those who are tempted to do the installation yourself, it is NOT worth it! If you think that using your wall outlet “just makes sense”, just realize that you are “playing with fire”, LITERALLY!
Most wiring of houses is not intended to be used with a generator, therefore making it undersized for this purpose. This means that it can easily get overloaded and overheated, eventually causing a fire…
So, here are three main reasons why you SHOULD NOT plug your generator into the wall outlet:
- You don’t want an unprotected circuit that is a fire hazard.
- You don’t want to be liable for people’s lives and injuries due to backfeeding.
- You want to be compliant with National Electric Code (NEC) rules.
Here is another good reason for not using your wall outlet. If you found one (and think it is totally isolated from the main breaker, even though this is still illegal), you will have to deal with something called a:
That many people believe should not exist in a first-place due to how dangerous it is! With a normal cord, when one side goes into the outlet, the other is protected by prongs being inside and hidden.
In the case of the “suicide cord” (which technically is a “male to male” cord, where prongs on both sides are outside), when you plug it, the prongs are not isolated, but power already flows through the plug! It is extremely easy to get an electric shock from the other side, anybody could grab it by accident!
This is what it looks like:
Since you have a male end with power that can touch you when you’re handling it or another conductive substance, this is potentially harmful. Do not just think of yourself, consider that there are people around you that could get hurt! It is NOT worth the risk!
Not to mention that using an already wired outlet for wrong purposes (generator) could burn up your house and be backed into utilities (if the outlet is not isolated) and that means you endanger the lives of lineman fixing the problem. Did I mention it was illegal?🤔
During a power outage, a generator’s back feed into power lines might result in “hot” power lines, instead of “dead”. When a generator is improperly connected to a home electrical system (whether through outlet or panel without transfer switch), you will have two main problems:
- Your house wiring will be likely overloaded and overheated, posing a serious fire danger.
- You might activate the de-energized power wires outside your home, posing a life-threatening situation to linemen who are unprepared for the lines to be “hot.”
Difference between an extension cord and suicide cord
So, what’s the difference between an extension cord and a suicide cord? An extension cord on one end has prongs, and on the other, it has a socket. NOT double prongs on each end! It looks like this:
Or like this:
Why it’s not as dangerous as a male-to-male plug? Because there is no way to touch live parts within the socket since they are hidden! Both ends of a suicide cable have prongs. That means if you touch it as it becomes live, you can easily get an electrical shock.
Dedicated generator outlet
Yes, you can have an outlet dedicated to your generator, as long as it is NOT connected to main house wiring and the wire is appropriately sized.
“It is NOT the same as using ANY outlet that you find in your house!”
Even if your electrician checked the existing outlet for the mains connection, he could make a mistake, and you will pay for it! So if you need an outlet (which is a good idea, since you probably don’t want doors and windows open during a power outage), get an electrician to install one.
This outlet will be an inlet (or male receptacle) on the outside and all you have to do is use a regular generator plug or extension to use it. Once again, if you find a female receptacle in your garage (and even if you remember to turn the main power OFF while using your generator with a suicide cord) it is still unlawful and very dangerous to use!
National Electric Code, paragraph 700-6 states:
“Transfer equipment shall be designed and installed to prevent the inadvertent interconnection of normal and emergency sources of supply in any operation of the transfer equipment. Automatic transfer switches shall be electrically operated and mechanically held.”
Source (PDF file)
The transfer switch should break the electrical connection with commercial power lines before allowing the power to flow through generator wires. When regular service is restored, the switch will also prevent utility electricity from harming the generator.
What Amperage Should You Use for Your Transfer Switch? Transfer switches are rated in “amp ratings”, which basically means the number of amps it can handle. A transfer switch that can handle 30 amps, for example, is referred to as a size 30 transfer switch.
The simplest method to figure out the needed transfer switch rating, all you have to do is look at the outlet on your generator. If your generator’s biggest outlet is 30 amps, get a 30-amp transfer switch. If it’s 50-amps, get a 50-amp transfer switch.
“Transfer switch should be sized the same or higher rating than the primary overcurrent protection.”
Transfer switches can be automatic:
Always seek the advice of a certified and experienced electrician and adhere to all applicable construction and electrical codes. Have a professional install a transfer switch as code requires, and then plug a generator into it.
Having a sub-panel that gets electricity from either the main panel or a generator and installing an interlocking switch is another possible safe option for connecting your generator. In this case, the interlocking switch would prevent both of mains and generator from being used at exactly the same time.
All you have to do is install an appropriate breaker in the main panel that will feed the sub-panel (the wiring size is determined by the load size). Then, install two appropriate size breakers and the means of isolating them (or an interlocking kit ) in the sub-panel, with one getting power from the main panel and another – from the generator.
There are many different interlocking setups variations available:
Here is another one:
And another one:
When a generator is in use, this setup will NOT allow the backfeed into utilities or the generator when the power comes back. Since you probably will not use your generator (especially portable) to power your whole house, install breakers in the sub-panel for circuits that will be powered by the generator.
As you see, it is not complicated to set up your generator correctly in order to avoid costly and dangerous mistakes. Don’t forget that the permit is needed to install a transfer switch, so get professional assistance.
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