30 Amp Vs 20 Amp (It’s Use, Size, Billing, Plug, Breakers)

30 amp vs 20 amp difference

Your circuit has an amp rating. It also features a breaker that trips whenever you exceed its capacity. 20 and 30-amp breakers are separated by ten amps. However, the differences between the two ratings are more significant than you realize.

30 Amp VS 20 Amp Differences

Watt (120V)2400W3600W
Wire Size12AWG10AWG
UsesResidential SettingsHeavy Duty Items
RVLocated InsideLocated Outside

1). 20A Is Used For Residential Settings

20A is the equivalent of 2,400 watts (120V). That includes 15,000 BTU AC units, which use an average of 2,000 watts, space heaters (1,200 watts), microwave ovens (1,200 watts), and cookers (1,500 watts).

20-amp circuits are the norm, along with 15 amps circuits. If you live in an average home with ordinary appliances like TVs, heaters, and stoves, you can run them on a 20A circuit.

Though, you can only use 80 percent of a circuit’s capacity. Therefore, if you have a 20A circuit, you should only use 16 amps. You have to consider this factor whenever you perform your calculations.

To determine whether or not a 20A circuit is appropriate for your home, you must add up the amp ratings of all the devices and appliances you want to use. The total amperage cannot exceed the capacity of the circuit. In the case of a 20A circuit, the total amperage shouldn’t exceed 16 amps.

Additionally, you have to give heavy-duty items like toasters and microwaves dedicated circuits. Fortunately, most kitchen devices can run on a 20A circuit.

You don’t have to upgrade to 30 amps unless you observe signs of overloading, including flickering lights, overheating, and buzzing outlets.

2). 30A Is Used For Heavy Duty Applications

30-amp circuits are not common in residential settings. They ran the same items you find on 20A circuits, including electric ranges, ovens, dryers, washing machines, and the like. But in this case, the models have heavier electrical requirements.

You can find electronic equipment in every conceivable electrical range. Some electric heaters work on 20A circuits. Others require 50 amps. You can install a 30A circuit if you expect to use heavy items like electric arc welders that tend to overwhelm conventional 20A circuits.

30A gives you 3,600 watts (120V). However, if you have an ordinary home that uses conventional equipment, stick with 20 amps.

2). 20A Uses 12AWG While 30A Uses 10AWG

Are you tempted to upgrade your breakers from 20 amps to 30 amps? Before you take this drastic step, you need to realize that replacing the breakers in the panels is not enough. You will burn your house down.

This is because 30A circuits use larger wires than 20A circuits. 20A uses 12AWG wire. On the other hand, 30A uses 10AWG wire.

With the gauge, the thickest wires have the smallest numbers. Therefore, 10AWG is thicker than 12AWG wire.

You cannot afford to use thinner wires on a 30A circuit. The circuit will transmit more power than the 12AWG wire can handle, especially if the connected appliances are designed to utilize 30 amps.

The thin cables will overheat, melt, and start a fire. In other words, you can’t replace the breaker unless you have the means to change the wiring as well.

3).No Change In Bill

The circuit size won’t affect your energy bills, not directly. Your electric bill is determined by the number of electric devices you have in the home and the amount of usage they get.

You could argue that running a 24A heater on a 30A circuit will cost you more money than a 12A heater on a 20A circuit. If you have a larger circuit, you are more likely to use heavy-duty items that consume a lot of electricity.

But some people use 12A heaters on 30A circuits. The circuit size alone cannot shape your energy consumption.

Though, you can save money by using larger wires. Electrons move slower in a small wire than in a large wire. This is because larger wires have lower resistance than their smaller counterparts. Larger wires are also less likely to overheat. This makes the cables more efficient conductors. 30A circuits use larger cables than 20A circuits.

4). 20 & 30A Breaker Looks Same

Most breakers look the same. The amperage doesn’t affect their appearance. They use different gauges. 20A breakers use 12AWG conductors. 30A breakers use 10AWG conductors. However, the exterior design is the same.

20A and 30A breakers have labels. This is the easiest way to tell them apart. Otherwise, the layperson cannot separate a 20A breaker from a 30A breaker by simply looking at them.

5). Difference In Plug

20A and 30A plugs are different. This is because their outlets are not the same. You cannot push a 20A plug into a 30A receptacle, especially in an RV.

Look at this picture!


6). Difference In RV Power Outlet Panel

Camper Upgrade says that 20-amp sockets can operate most RV appliances without a problem. They have fuses to defend against overloads. While you find 20A outlets inside the RV, 30A receptacles are typically located outside. You use them to connect the RV to a separate power source.

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Can I Use A 30 Amp Breaker Instead of 20 Amps?

You can use a 30-amp breaker in place of a 20A breaker. The 30A breaker will slide into the same slot as the 20A breaker. However, the practice isn’t necessarily legal.

Check your local code. More than likely, it will tell you to install 20A breakers on 20A circuits and 30A breakers on 30A circuits. If you refuse to adhere to these regulations, you may incur hefty penalties.

Is It Safe?

It is not safe. First of all, you have to remember that a 20A breaker will trip once the load exceeds 20 amps. A 30A breaker increases the threshold by ten amps. The breaker will only trip once the load exceeds 30A.

However, you probably considered this outcome. In fact, many people install larger breakers because they have breakers of a smaller size that keep tripping. They want to increase the capacity of the breaker to use heavier equipment.

But you have a more significant concern. 20A breakers use 12AWG conductors. If you install a 30A breaker, you must replace 12AWG with 10AWG. If you don’t, the 30A breaker will pull more electricity than the 12AWG wire can handle.

The conductors will overheat, starting a fire. This is not a guaranteed outcome. A 30A breaker can withstand 30 amps (or 24 amps if you use the 80 percent rule). But you don’t have to reach that threshold. If you have low or medium-duty devices like laptop chargers and lamps, you can use a 30A breaker without changing the wiring.

The cables won’t overheat because laptop chargers and lamps cannot draw enough power to exceed the 30A breaker’s capacity. But the risk is too high.

What if someone connects a 25A power tool to one of your outlets?

If you had the 20A breaker, it would trip long before the wires melted.

The 30A breaker won’t respond in time. The safer option is to replace the wiring to match the capacity of the new breaker. Naturally, many homeowners are hesitant to take this step because it can be a costly undertaking.

Can I Use A 20 Amp Breaker Instead of 30 Amps?

You can use 20-amp breakers on a 30-amp circuit. The 20A breaker can enter the slot the 30A breaker once occupied. Most of these breakers are the same. Or, at the very least, they have the same shape and size. If you have a basic understanding of electricity, you can install the 20A breaker without the assistance of an electrician.

Is It Safe?

Replacing 20A breakers with 30A is dangerous because the 30A breaker will permit the cables to transmit more current than they can safely carry. The reverse is not an issue.

30A breakers use 10AWG wire, which is thicker than the 12AWG cabling that 20A circuits use. Therefore, you don’t have to worry about the 20A breaker causing the cables on a 30A circuit to overheat.

10AWG conductors can withstand 20 amps with ease. However, the breaker will become a severe source of irritation for your household. If your appliances require a 30A circuit, they will cause the 20A breaker to trip incessantly.

Some laypeople think that 30A appliances will start fires if you pair them with a 20A breaker. But breakers are supposed to trip when you force them to transmit more current than their rating permits. A 20A breaker will do its job when exposed to a 30A appliance. It will trip whenever you activate the 30A device, depriving your home of power.

You should only replace the 30A breaker with a 20A alternative if your equipment uses 20 amps or less (Don’t forget the 80 percent rule). Otherwise, stick with the 30A breaker.

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