If you’re a meticulous RVer like me, you might have asked yourself this question, “what gauge extension cord do I need for an RV?” You indeed need to know the correct gauge to power your electronic devices properly.
Generally, we recommend 15A RVs with a 10 or 12 gauge extension cord, 30A RVs with a 10 gauge wire, and 50A RVs with a 6/3 + 8/1 or 6/4 gauge 50A extension cord. You can also round down the quotient of the total wattage and 110 to the nearest whole number.
What’s a Wire Gauge Exactly?
Extension cords contain a copper wire in the center in different thickness levels. The thickness can be rated by American Wire Gauge (AWG). The most common AWG ratings are 8, 10, 12, 14, and 16.
For the efficient operation of your devices, you need to offer full power. Without sufficient power to run your rig, there will be damage to your electrical appliances, may overheat, and cause fires or surges.
Keep in mind that a smaller number indicates a thicker wire, which means delivery of more power. Using a thin wire can result in very high resistance. Hence, you should select a thick wire that suits your appliances.
Also, resistance can be high when you use a longer wire. Choose a shorter wire with a lower AWG rating if you’re facing resistance.
A bulk extension cord wire isn’t similar to an RV cord, although it may fit your RV plugs. An RV power cable is heavy-duty and often has better weatherproofing. This type has great locking ends, making it sturdy to hook to your power pedestal and rig.
Are RV extension cords safe? Definitely, as long as you use the properly rated ones to carry the right amount of current needed. Also, make sure that the cord is labeled for outdoor use when using it for outdoor purposes.
RV’s Size and Amp Power Matter
You can estimate the correct gauge by looking at the size and amp power of the RV.
- 15A RV – 10 gauge extension cord:
The smallest RV that requires 15A power can run smoothly with a 10 gauge extension cord.
You should go for an RV electrical extension cord with a very sturdy jacket with thick wire strands and can run at any length. A 12 gauge extension cord can also suffice to power a 15A RV at a minimum.
- 30A RV – 10-gauge extension cord:
The most common size of RV is the 30A RVs that run for 30 Amps at 125 Volts. These 30A RVs have no problem running devices with 10-gauge extension cords. Keep in mind that a longer extension cord means a lower AWG rating required.
- 50A RV – 6/3 +8/1 or 6/4 gauge extension cord:
The most powerful in the RV world is rated for 50 Amps at 125/250 Volts like some large 5th wheels and Class As. These 50A RVs can do well with a large gauge, specifically a 6/3 +8/1 or 6/4 gauge extension cord.
Calculating the Right Gauge
One way to know the correct gauge for all your electronic devices is to calculate it yourself. Simply add the total wattage of all electronic devices in your RV. You can find the required wattage of the device, typically at the back or bottom.
Once you get the total wattage, divide that number by 110 and round down to the closest whole number.
For example: Total wattage = 1500W/110 = 13.6
Round down = 13 gauge
Most equipment will run properly with 12 gauge extension cords. A 10 gauge extension cord for RV is ideal for running ultra heavy-duty equipment such as a 240-volt window air conditioner and a 30-amp electric water heater.
Finding the Right Length
A longer extension cord may sound practical as you don’t need to connect multiple cords just to reach the closest external power outlet. However, this could also mean a higher voltage drop due to the rise of resistance.
You want to find the shortest cord that fits your needs, as excess is heavy and takes up plenty of space in your rig. Power tends to reduce as the cord gets longer.
Typically, 20-30 feet is plenty for most campgrounds, but make sure to measure when you want to plug in at your house. If you must get a cord longer than 30 feet, consider the load. You can get a longer cord, like a 50 foot 50 amp RV extension cord, but just limit how much power you consume.
The Role of Voltage Drop and Temperature Rise
Besides the required amperage, when choosing the right extension cord for the shore power, the other factors are voltage drop and allowable temperature rise. A voltage drop means the amount of voltage loss that happens through all or portions of a circuit due to resistance.
Let’s say you only have a 14- or 16-gauge extension cord to hook your 30 amp RV with a series of dog-bone camper power cord adapters.
According to this chart, a 14 gauge cord only allows 15 amps of current to pass safely. If you want to pass 30 amps on this cord, you’ll need a long cord with a voltage drop as low as 100 volts.
That may be possible, but you may run the risk of overheating your extension cord. For your safety, you need a minimum of 10 gauge to pass 30 amps of current. A 10 gauge extension cord will have almost no voltage drop and less heating.
Hooking Up Air Conditioners and Generators
Your RV serves as your second home, so it’s only practical to equip yourself with many functional appliances.
- One appliance you should have in your camper is an air conditioner to stay cool in hot weather.
- You can’t risk running your RV air conditioner to those cheap orange extension cords.
- A 14 gauge extension cord will produce too much voltage drop when the compressor starts, especially if the cord is 50 feet long or more. When this occurs, it will put a toll on your compressor and affect the cooling factor.
- We recommend finding a proper outlet in the rig to hook your appliance and using a 10 gauge extension cord for RV to pass a 30-amp circuit.
- Also, consider using a 6 gauge extension cord to support a 50 amp shore power current to avoid overheating problems.
- A generator is another device that needs an extension cord to connect RV appliances. You need to choose the right gauge so as not to run the risk of damaging the appliances and generator. The ideal extension cord for generators should be durable, flexible, and well-built.
Learn how to create a 30 amp extension cord for generator cord here.
So, we have answered the question. “What gauge extension cord do I need for an RV?” It all boils down to the amperage required, voltage drop, and allowable temperature increase. Typically, you want to use a 10 gauge extension cord for a 15 amp or 30 amp RV. A 50 amp RV needs a 6/3 +8/1 or 6/4 gauge extension cord.
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