How Many Watts is 30 Amps? (Answered in Detail)

Written by Edwin Jones / Fact checked by Andrew Wright

Most appliances are rated in terms of power or watts. So, converting 30 amps to watts is useful when planning the appliances you can connect to a circuit, especially for a high-powered appliance at home or in an RV.

So how many watts is 30 amps? It’s 360 watts at 12 volts DC, 3600 watts at 120 volts AC, and 7200 watts at 240 volts AC.

How Can I Calculate Watts?

If we want to know how many watts can 30 amps handle, then we need to know the conversion using the definition of electric power:

Here is a chart of the power of 30 amps at different volts:

 30 amps to watts at different voltage Voltage (volts) 12 24 110 120 220 240 Power (watts) 360 720 3300 3600 6600 7200

Of course, the definition of power can be used if you want to find other electrical units. If you need to know how many volts or amps your appliance demands, simply use these formulas:

$\text{Voltage} = \frac{\text{Power}}{\text{Current}}$ for 30 amps to volts

$\text{Current} = \frac{\text{Power}}{\text{Voltage}}$ for watts to current

In some cases (mainly with AC circuits), you may want to account for the power factor and voltage type in your calculation.

• Single-phase circuits will have a wattage that equals 30A x power factor x voltage
• Meanwhile, three-phase circuits can use the following formulas:

$30A \times \sqrt{3} \times \text{power factor} \times \text{voltage}$ (if the voltage is line-to-line)

$30A \times 3 \times \text{power factor} \times \text{voltage}$ (for line-to-neutral connections)

For example, if the line-to-line voltage is 480 and the power factor is 0.5, the wattage will be: 30 x √3 x 480 x 0.5 = 12471.

Residential Setting

1.  What are some appliances that use 30 amps at home?

High-powered devices like electric dryers and some electric ovens are commonly connected to 30 amp circuits. These devices use a double pole circuit breaker at 240 volts, which has two poles and two hot wires.

Single pole breakers at 120 volts do exist, but they are rarer and often used for charging RVs. Older homes will use a 30 amp fuse instead of a circuit breaker.

2. How many amps can a 30-amp circuit for residential appliances handle?

These 30 amp dedicated circuits can potentially power up to 7200 watts in a 240 volt circuit based on our table. Also, most of these appliances do not run on continuous loads, so they do not have to follow the 80% limit for wire and breaker sizing. These appliances can run on 30 amps in the home.

Electric dryers can use 1800 to 5000 watts while electric ranges can use multiple 1000 to 3000-watt burners simultaneously. It’s rare, though, for these appliances to even use the full 7200 watts.

We could work out the expected amp draws of these appliances with their power requirements using the formulas above (without accounting for circuit phases and efficiency):

 Residential appliance Power (watts) Voltage (volts) Current (amp) Electric dryer 1800 – 5000 240 7.5 to 20.8 Electric range (e.g. with 2 high-powered and 1 low-powered burner with all three running) High-powered burners 2 x 3000 = 6000 Low-powered burner 1 x 1000 = 1000 Total = 7000 240 Up to 29.2

3. How can I reduce the power consumption of these appliances at home?

The US Department of Energy states that electric dryers consume more energy in our electrical system than refrigerators and dishwashers per year. Here are some ways to save energy when using your electric dryer:

• Use a dryer with Energy Star certification, or use heat pump dryers.
• Do your laundry during off-peak times when electricity is cheaper.
• Use cold water instead of warm water.
• Hang laundry to air dry instead of using the dryer.

Unlike electric dryers, residential electric ranges are not rated by Energy Star. But there are other ways to reduce the power consumption of electric ranges:

• Clean your oven on a regular basis.
• Use convection ovens and cook multiple dishes at the same time.
• Set the oven at the right temperature.

RV Setting

RVs can use 30 amp circuits in two ways. One use is for RV hookup, and the other is for RV electrical service boxes. We’ll talk about each one in detail:

1. How does an RV use 30 amp circuits when charging?

30 amp circuits are used for charging RVs with lower power needs. They are also found in some campgrounds as available hookups, but you can certainly have a hookup or outlet box at home if you need to. RV outlet boxes at 30 amps are set to 120 volts, so they can potentially deliver up to 3600 watts (or 3600 VA).

2. How does an RV use 30 amp service panels?

30 amp service panels in RVs are quite different from service panels in a residential setting. These panels are set at 110 volts or 120 volts AC with one live wire, one neutral wire, and one ground wire, unlike residential panels that are set to 240 volts AC with two live wires instead of one.

The maximum capacity RV service panels have is up to 3600 watts.

3. What can you run on 30 amps service panels?

30 amps service panels are quite limited in the number of appliances you can use at the same time. Remember that the key is to stay within the 3600-watt limit, so carefully plan when to use these appliances. Here are some appliances common in an RV with their power ratings and current draw:

 Appliance Power rating (watts) Current draw (amps) at 120 volts 32 inch LED TV 20-60 0.17-0.5 Electric iron 1000 8.3 Hair blow dryer 1800-2500 6.7-21.0 Microwave 600-1700 5-14.2 Refrigerator 725 6 Toaster 700-1000 5.83-8.33 Washing machine 500 4.2 Roof air conditioner (10,500 BTUs) 3000 25

4. How can I reduce the power consumption in an RV?

Here are some ways to keep your battery charge longer when you are living on 30 amps. Some of these include limiting the use of appliances or changing the way you power your RV:

• Use devices with Energy Star certification.
• Use a solar-powered generator.
• Minimize the use of your air conditioner.
• Go for a smaller RV.
• Use your appliances when you are in a campground with hookup boxes.

Conclusion

30 amps can deliver 360 watts at 12 volts DC, 3600 watts at 120 volts AC, and 7200 watts at 240 volts AC. If we want to know how many watts is 30 amps in other voltages, we simply use the equations above for a quick answer.

30 amps are common in residential and mobile settings. They can supply high-powered equipment at home or they can power an RV and its appliances. Knowing how many watts you need can help maximize the use of your 30-amp circuit.

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