How many amps does an RV air conditioner use? An RV air conditioner needs a lot of power. The exact number of amps it uses changes. It uses more power to start up than to run. A typical 13500 BTU RV AC unit might use around 12-15 amps when running and 50-60 amps to start. A larger 15000 BTU RV AC unit might use 13-16 amps running and 60-70 amps to start. This big jolt of power at the start is important to know.
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Grasping RV Air Conditioner Power Use
An RV air conditioner is a big power user. It cools your RV on hot days. But it needs a lot of electricity to do this. This need for power is measured in amps. Knowing how many amps your RV air conditioner uses is very important. It helps you know what kind of power you need. You need enough power from the campground plug, your generator, or your battery system. If you do not have enough power, the AC unit will not start or run right. It might even trip breakers.
The power an RV air conditioner uses is not always the same. It changes when the AC starts and when it is just running. We talk about this power need in amps.
- Startup Amps: This is the power needed for a very short time when the AC first turns on. The motor needs a big push to get going. This push uses a lot more amps than running.
- Running Amps: This is the power needed to keep the AC running once it is already on and cooling. This number is much lower than the startup amps.
Knowing both startup amps and running amps is key. The high startup amps are often the main problem when you do not have enough power.
Deciphering Startup Amps
Think about pushing a heavy box. It takes a lot of effort to get it moving from a stop. Once it is moving, it is easier to keep pushing it. An RV air conditioner motor is like that heavy box.
When the AC unit first gets power, its motor has to start turning the compressor. The compressor is the part that does the main work of cooling. Getting this part moving from a stop needs a large burst of electricity. This burst is the startup amp draw.
This burst happens very fast. It might only last for a fraction of a second. But the power source must be able to give that much power right away. If it cannot, the AC will not start. Or it might try to start, hum loudly, and then shut off. This can be bad for the AC motor over time.
How many startup amps does an RV AC use? It depends on the size of the AC.
- A small 11000 BTU unit might need around 40-50 startup amps.
- A common 13500 BTU unit might need 50-60 startup amps.
- A large 15000 BTU unit might need 60-70 startup amps or even more.
These numbers are just rough guides. The real number can be different for different brands or models. It can also change based on how hot it is outside. A hotter day means the AC has to work harder to start. This can make the startup amps even higher.
Fathoming Running Amps
Once the AC motor is running, it needs less power. This is like keeping the heavy box moving. It still takes power, but not the big push needed to start. This lower, steady power use is the running amp draw.
The running amps are what the AC uses the whole time it is cooling your RV. This is the number you use to figure out how much power the AC uses over time. It tells you how much of your available power is being used while the AC is on.
How many running amps does an RV AC use? Again, it depends on the size of the AC unit.
- A small 11000 BTU unit might use around 9-11 running amps.
- A common 13500 BTU unit might use 12-15 running amps.
- A large 15000 BTU unit might use 13-16 running amps.
Like startup amps, these are estimates. Check your specific AC unit for the exact number. The running amps can change a little based on how hard the AC is working. If it is very hot outside, the AC might use a bit more power to keep cooling. But the change is not as big as the difference between startup and running amps.
Knowing the running amps helps you add up the total power needed for all your RV appliances. You can run other things at the same time as the AC as long as the total running amps do not go over the limit of your power source.
Specific Amp Draw for Common RV AC Sizes
Most RVs use one of two main sizes of air conditioners: 13500 BTU or 15000 BTU. BTU stands for British Thermal Unit. It is a way to measure how much cooling power an AC has. A higher BTU number means more cooling power.
Let’s look closer at the typical power needs for these common sizes. This is the RV air conditioner power consumption for these popular units.
13500 BTU RV AC Power Usage
This is a very common size for many RVs, especially mid-size campers and travel trailers. It provides good cooling for many spaces.
- Typical Running Amps: Around 12 to 15 amps.
- Typical Startup Amps (RV AC startup amps): Around 50 to 60 amps.
So, if you have a 13500 BTU RV AC, expect it to pull 12-15 amps steadily when running. But be ready for that quick jump to 50-60 amps when it first kicks on. This high startup number is often the challenge.
15000 BTU RV AC Amp Draw
This is a larger size, often found in bigger RVs, fifth wheels, and motorhomes. It offers more cooling power, which is good for larger spaces or hotter climates.
- Typical Running Amps: Around 13 to 16 amps.
- Typical Startup Amps (RV AC startup amps): Around 60 to 70 amps, sometimes even higher.
A 15000 BTU unit uses a bit more power than a 13500 BTU unit, both when running and when starting. That startup jolt is even bigger. This means you need a stronger power source to start this type of AC.
It is important to check the specific label on your RV AC unit. The actual numbers can vary based on the brand, model, and how old the unit is. The label, often found on the side of the unit’s cover or in the inside air return, will tell you the exact power needs. Look for amps (A) or watts (W). Watts can be changed to amps if you know the voltage (Volts, V). Amps = Watts / Volts. RV ACs usually run on 120 volts.
What Makes Amp Draw Change?
The amp draw of an RV AC is not always the same exact number. Several things can make it change.
- Outside Temperature: The hotter it is outside, the harder the AC has to work. This can make the running amps a little higher. It can also make the startup amps higher because the compressor is under more pressure.
- Inside Temperature: If your RV is very hot inside and you turn on the AC, it will work harder at first. The running amps might be a bit higher until the temperature gets closer to the setting.
- AC Unit’s Condition: An older or dirty AC unit might use more power. Dirty filters, coils, or problems with the motor can make it less efficient. This means it needs more amps to do the same job. Regular cleaning and service help keep the amp draw lower.
- RV AC Voltage: The voltage of the power source matters. RV ACs are designed to run on 120 volts. If the voltage is too low (called low voltage), the motor has to pull more amps to get the same amount of power (watts). This can make the unit run hot and might damage it. It is best to have a steady 120 volts. Using a surge protector with low voltage shutoff is a good idea.
- Length of Wire: If the power cord from your source (like a generator) is very long or too thin, it can cause voltage drop. This is like low voltage and makes the AC pull more amps. Always use a power cord that is the right thickness (gauge) and not too long.
Finding Your Specific AC Unit’s Amp Draw
You don’t have to guess how many amps your RV AC uses. The information should be right on the unit itself. This is the most accurate way to know.
Look for a sticker or metal plate on the RV rooftop air conditioner amps unit. It might be on the cover you see from the roof, or inside the RV on the part that blows air, near the filter.
This label is called a data plate or nameplate. It will list important details like:
- Model number
- Serial number
- BTU size (like 13500 or 15000)
- Voltage (usually 120V)
- Frequency (usually 60 Hz)
- Running amps (sometimes listed as RLA – Rated Load Amps or MCA – Minimum Circuit Amps)
- Startup amps (sometimes listed as LRA – Locked Rotor Amps)
- Watts (sometimes)
Look for the RLA or running amps and the LRA or startup amps. The LRA is the big number you need to worry about for starting the unit. The RLA is the number you need for adding up total power use while running.
If you cannot find the label or read it, check the manual for your RV AC unit. You can often find manuals online by searching for the brand and model number.
Power Sources and Your RV AC Amps
Now that you know how many amps your RV AC needs, you can figure out if your power source is strong enough. RVs get power from different places.
- Shore Power: This is the power plug-in at a campground. Campgrounds usually offer 15, 20, 30, or 50 amp service.
- 15 or 20 amp service: Usually not enough to start or run an RV AC, especially a 13500 or 15000 BTU unit, along with other things. You might be able to run a very small AC or nothing else.
- 30 amp service: This is common. It gives you a total of 30 amps at 120 volts (3600 watts). A 13500 BTU AC running at 12-15 amps leaves you about 15-18 amps for other things. A 15000 BTU AC running at 13-16 amps leaves about 14-17 amps. The challenge is the startup amps. The campground breaker might be 30 amps, but it can often handle a short burst much higher, like 60-70 amps, to let the AC start. However, if you have other things running when the AC tries to start, the total demand might trip the breaker.
- 50 amp service: This is the strongest common service. It gives you two lines of 50 amps at 120 volts each, for a total of 100 amps service (12000 watts). This is plenty for running one or even two RV AC units and all your other appliances at the same time. Starting the AC is not usually an issue on 50 amp service.
- Generator: A generator makes electricity. You need a generator big enough to handle the startup amps of your AC, plus the running amps of the AC and anything else you want to run.
- For a 13500 BTU AC: You might need a generator that can handle 50-60+ amp surges. This often means a generator rated for at least 3000-3500 watts. 3000 watts at 120V is 25 amps steady, but the generator needs to have a higher surge rating.
- For a 15000 BTU AC: You might need a generator that can handle 60-70+ amp surges. This often means a generator rated for at least 3500-4000 watts or more.
- Checking the generator size for RV AC is critical. Look at the generator’s peak or surge wattage rating. It should be higher than the watt equivalent of your AC’s startup amps. Watts = Amps x Volts. So, a 60 amp startup at 120V is 7200 watts for a moment. A generator needs a surge rating high enough to handle this brief spike.
- Battery Bank and Inverter: If you have a battery bank and an inverter, you can run AC power things like the AC. However, running an RV AC from batteries uses a lot of power. A large battery bank and a powerful inverter are needed.
- The inverter must be big enough to handle the AC’s startup surge (wattage rating).
- The battery bank must be large enough to supply the running amps for as long as you want the AC on. Running a 12-15 amp AC (1440-1800 watts) will drain typical RV batteries very quickly. This is usually only done for short periods or with a very large, expensive battery system (like lithium batteries).
To figure out your total power need, add up the running amps of everything you want to use at the same time as the AC. Make sure this total is below the continuous limit of your power source. Also, make sure the power source can handle the AC’s startup amp surge.
Interpreting the Soft Start for RV AC
Dealing with the high startup amps of an RV AC can be a problem, especially on 30 amp service or with smaller generators. A soft start for RV AC is a device that helps with this.
What does a soft start do? It is an electronic device installed on the AC unit. When the AC starts, the soft start controls the power going to the compressor motor. Instead of letting the motor pull one big jolt of power, the soft start sends power slowly at first, then ramps it up smoothly.
This makes the startup amp draw much lower. Instead of maybe 60 amps instantly, the AC might start with a more controlled peak of 20-30 amps.
Why use a soft start?
* It lets you start your AC on lower power, like a 30 amp hookup even with other things running.
* It can allow you to run your AC on a smaller generator than you would normally need. Maybe a 2000-2500 watt generator instead of 3000-3500 watts.
* It can make it possible to start your AC using a battery bank and inverter that might not handle the full surge otherwise.
* It is easier on the AC motor, which might make it last longer.
A soft start is a popular upgrade for RVers who want more flexibility in where and how they can run their AC. It does not change the running amps, only the startup amps.
RV Appliance Power Draw Chart
It is helpful to compare the power use of the RV AC to other things in your RV. This helps you manage your power. Here is a simple chart showing typical power use for common RV appliances. Remember these are estimates and can vary. Power use is shown in both watts and amps (assuming 120 volts).
| Appliance | Typical Watts (Approx.) | Typical Running Amps (Approx.) | Notes |
|---|---|---|---|
| RV Air Conditioner (13.5k BTU) | 1500 – 1800 | 12 – 15 | High startup amps! |
| RV Air Conditioner (15k BTU) | 1600 – 1900 | 13 – 16 | Higher startup amps! |
| Microwave Oven | 1000 – 1500 | 8 – 13 | Used for short times. |
| Electric Water Heater Element | 1000 – 1500 | 8 – 13 | Only on when heating. |
| Electric Coffee Maker | 600 – 1000 | 5 – 8 | Used for short times. |
| Toaster | 800 – 1200 | 7 – 10 | Used for short times. |
| Hair Dryer | 1200 – 1800 | 10 – 15 | Used for short times. |
| Converter (Charging Batteries) | 50 – 800+ | 0.5 – 7+ | Varies greatly by battery charge level. |
| TV (LED) | 50 – 200 | 0.5 – 2 | Lower for smaller/newer TVs. |
| RV Refrigerator (on Electric) | 100 – 400 | 1 – 3.5 | Runs all the time. |
| Lights (LED) | 0.5 – 2 per light | Very low | Very power efficient. |
| Fan | 20 – 50 | 0.2 – 0.4 | Low power use. |
This RV appliance power draw chart helps show why running an AC plus a microwave, coffee maker, or hair dryer at the same time on 30 amp service is often not possible. The running amps alone can add up fast, even before thinking about startup amps.
RV AC Voltage Explained
RV ACs work using RV AC voltage. In North America, this is almost always 120 volts (V). Power sources like shore power, generators, and inverters give this voltage.
Amps (A) measure the flow of electricity. Volts (V) measure the pressure or force of the electricity. Watts (W) measure the total power. The simple relationship is:
Watts = Volts x Amps
So, if you know the watts a device uses and the volts it runs on, you can find the amps:
Amps = Watts / Volts
For example, a 1500 watt appliance on 120 volts uses 1500 / 120 = 12.5 amps.
It is important that your power source provides the correct voltage, close to 120 volts. As mentioned before, low voltage makes motors pull more amps to get the needed power (watts). This extra current can cause problems like overheating. High voltage is also bad and can damage electronics. Using a voltage monitor or protector is a good idea.
More on RV Rooftop Air Conditioner Amps
Most RV air conditioners are located on the roof. These are called RV rooftop air conditioner amps. They work the same way as any other RV AC unit in terms of power use (startup and running amps). The location does not change the basic electrical needs.
The key thing about rooftop ACs is that they are usually the biggest power user in the RV. Because they are on the roof, the wires running to them go from the breaker panel up to the roof unit. These wires need to be thick enough to safely carry the needed amps, especially the high startup amps. The breaker protecting the circuit for the AC must also be sized correctly. A typical 13500 or 15000 BTU AC might have a 20 amp or 30 amp breaker. This breaker is sized for the running amps, but it is designed to allow the brief startup surge without tripping under normal conditions (unless other things are drawing power on the same circuit or the startup surge is too high for the power source).
If you are having problems with a rooftop AC not starting or tripping a breaker, it could be:
1. Not enough power from the source (shore power, generator).
2. Other appliances running at the same time, pushing the total amps over the limit when the AC tries to start.
3. Low voltage from the power source.
4. A problem with the AC unit itself (hard starting, dirty).
5. A weak breaker in the RV’s power panel.
Adding a soft start kit is a common solution for point #1 and #2, making it easier to start the RV rooftop air conditioner amps without tripping breakers on limited power.
Tips for Using Your RV AC Wisely
Knowing about amp usage helps you use your RV AC better and avoid power problems. Here are some tips:
- Know Your Numbers: Find the exact running and startup amp draw for your specific AC unit. Check the data plate or manual.
- Know Your Power Source: Understand the amp limit of the power source you are using (15, 20, 30, or 50 amp shore power, or your generator’s capacity).
- Prioritize Appliances: When on limited power (like 30 amp or a smaller generator), decide what needs to run. Can you wait to use the microwave or hair dryer until the AC cycle finishes?
- Start AC First: If possible, turn the AC on before turning on other high-power appliances. This deals with the startup surge when fewer other things are running.
- Use Fan Mode: On cooler days, use the fan mode instead of cooling. The fan uses much less power than the compressor.
- Keep it Clean: Regularly clean or change your AC filter. Clean the outside coils if you are comfortable and able to do so safely. A clean unit runs more efficiently and uses fewer amps.
- Insulate Your RV: Keep heat out. Close blinds or curtains. Use insulation for windows or roof vents. Shade your RV if possible. Less heat getting in means the AC runs less often and uses less power overall.
- Consider a Soft Start: If you often use 30 amp hookups or a generator and have trouble starting your AC, a soft start kit can solve this problem.
- Check Voltage: If you suspect power problems, use a voltage meter or a surge protector with voltage display to check the power coming into your RV. Low voltage is bad.
By paying attention to how many amps your RV air conditioner uses and managing your total RV appliance power draw chart, you can stay cool and avoid electrical issues in your RV.
Remember that different RV AC models and sizes will have different power needs. Always check the specifics for your unit. The common numbers for 13500 BTU RV AC power usage and 15000 BTU RV AC amp draw give you a good starting point, but your exact numbers might be slightly different.
Having enough power is key to a comfortable RV trip, especially in warm weather. Knowing about RV AC amp draw helps you plan your power needs, choose the right campgrounds, pick the right generator size for RV AC if needed, and decide if a soft start is right for you. It’s all part of managing your RV’s electrical system safely and effectively.
Frequently Asked Questions
h4> What is the difference between startup amps and running amps for an RV AC?
Startup amps are the high amount of power an AC needs for a very short moment to start the motor. Running amps are the lower, steady amount of power needed to keep the AC running and cooling.
h4> Why does an RV AC need so many startup amps?
The motor inside the AC, especially the compressor motor, needs a lot of force to start moving from a complete stop. This requires a big burst of electrical current, measured in amps.
h4> Can I run my 13500 BTU RV AC on a 2000 watt generator?
Maybe, but it’s often difficult or impossible without a soft start kit. A 2000 watt generator provides about 16.7 amps continuously (2000W / 120V). This might be enough for running amps (12-15A), but not for the typical 50-60 amp startup surge. A soft start reduces the startup surge, making it possible on many 2000-2500 watt generators.
h4> How can I lower the power my RV AC uses?
You cannot change the AC’s design amp draw. But you can make it run less often or more efficiently. Clean filters, insulate your RV better, keep blinds closed, and shade the RV. These steps reduce the heat inside, so the AC does not have to work as hard or run as long.
h4> Will a soft start reduce my RV AC’s running amps?
No, a soft start only reduces the startup amps. It helps the AC start on lower power, but once it is running, it will use the same amount of running amps it always did.
h4> Is 30 amp shore power enough for my 15000 BTU RV AC?
Yes, usually. 30 amp service provides 30 amps continuous. A 15000 BTU AC uses around 13-16 running amps, leaving about 14-17 amps for other things. The challenge is the 60-70+ amp startup surge. Most 30 amp breakers can handle this brief surge, but if you have other high-amp things running when the AC starts, the total demand might trip the breaker. A soft start helps prevent this.
h4> Where do I find the exact amp usage for my RV AC?
Look for a data plate or sticker on the AC unit itself, either on the rooftop part or the inside air return grill. It will list the running amps (RLA) and often the startup amps (LRA). Check your RV AC manual if you cannot find the label.
h4> Does low RV AC voltage hurt the unit?
Yes. If the voltage drops too low (e.g., below 110V), the AC motor has to pull more amps to get the power it needs (Watts = Volts x Amps). This higher current can cause the motor to overheat and potentially fail over time. Always try to provide stable 120V power.
h4> Are RV rooftop air conditioner amps different from other RV AC amps?
No, the term RV rooftop air conditioner amps just refers to the amp usage of an AC unit that is placed on the roof, which is the most common type in RVs. The principles of startup and running amps apply the same way.