It’s not uncommon to arrive at an RV park only to find a broken 30 amp plug or no 30 amp plug at all. So, what do you do if you have a 30 amp RV? Can you hook up a 30 amp RV to a 50 amp power plug?
Let’s take a look at how you can plug a 30 amp camper into a 50 amp plug but also do it safely.
Can You Hook Up a 30 Amp RV to a 50 Amp Power Plug?
The short answer is yes, but it’s not as simple as just plugging in your RV and hoping for the best. You really need to understand what you are doing and take appropriate safety measures to mitigate the risk of damage to your electrical system.
There are plenty of adapters out there that convert a 50 amp plug into a 30 amp plug for your RV. Here are just a few of the many 50A/30A options available on Amazon:
- Heavy duty electrical power adapter: 50 Amp Male to 30 Amp Female...
- High Quality: Heavy duty flame and anti fire & heat resistant PVC...
- NEMA: 14-50P to TT-30R - Rated 125V/3750W; Cord type STW
These devices are commonly known as dogbone adapters and are relatively cheap. However, it’s important to understand that there are risks associated with these adapters.
Is It Safe To Use A 50 Amp To 30 Amp Adapter?
There is a potential safety issue when using a 50 amp to 30 amp adapter. Dogbone adapters are commonly referred to as “dumb” adapters, which doesn’t mean they’re stupid per se. Rather, the term “dumb” refers to the fact that these adapters do not offer protection for your RV and can lead to a possible overload on your RV’s cable.
When you plug a 30 amp adapter into a 50 amp breaker at the pedestal, the 50 amp breaker will only pop if the amperage goes beyond 50 amps. The problem here is that these adapters and the power cord for your RV are only rated at 30 amps. This means you have an unprotected line with the potential to be overloaded by 20 amps before the breaker pops, which is dangerous.
Overloading a wire can cause the wire itself to burn up and even catch fire. It can also cause significant damage to electronics.
Does The RV’s Main Breaker Protect an Adapted Circuit?
Because the RV’s main breaker is installed in the distribution panel of the RV, the above scenario is unlikely. Most of the time, the RV’s main 30 amp breaker will pop before the 50 amp pedestal breaker does.
This scenario, however, does not fully protect your wires from becoming overloaded. If there were a short in the power cord or a fault in the breaker, your protection would be limited. Not to mention, even with the RV’s breaker, using a 50A/30A dogbone adapter without protection is technically an electrical code violation.
Electrical service always gets smaller breakers or fuses further away from the source. The wires should be rated to carry the load of the upstream breaker. This is called fuse or breaker coordination and is designed to always protect the lines at their maximum allowable amperage per electrical code. This mitigates most fire risks.
How to Safely Plug a 30 Amp RV Into 50 Amp Power Source
The safest way to plug a 30 amp camper into a 50 amp plug is to use a second adapter that offers overcurrent protection. This means you are putting a breaker or surge protector with overload protection in line between the dogbone adapter and your RV’s power cord. In this scenario, the surge protector will disconnect the line to prevent damage if an overload occurs.
Not all surge protectors have overcurrent protection or auto-off. Most only limit surges in voltage to protect electronics.
We highly recommend the 30 amp Watchdog Surge Protector with Auto-Off because it also has an overload disconnect function to protect your RV’s electrical system. Additionally, this model provides great data about your power usage and any problems with the power line.
If you are interested in one of these Hughes is offering our subscribers an exclusive discount of 10% off by using coupon code MORTONS at checkout!
If you prefer they are also available on Amazon.
- SMARTPHONE CAPABILITIES: Monitor voltage, amps, and watts on your...
- PROTECTION: Protects against 2, 400 Joules of energy
- CIRCUIT ANALYZER: Smart circuit analyzer will shut down power to...
Can You Hook Up a 50 Amp RV to a 30 Amp Plug?
Again, the answer is yes! This time, however, the simple dogbone adapters work safely. This is because too much amperage will trip the 30-amp breaker, keeping it from overloading the line. A simple, inexpensive adapter will do the trick:
- 【30M to 50F Adapter】30AMP (TT-30P) male to 50AMP (14-50R)...
- 【18’’ RV Adapter】Longer rv dogbone 30A to 50A adapter is...
- 【Grip Handle Design】Both ends of power adapter are designed...
While it isn’t necessary to protect the line, we still recommend getting a surge protector with Auto-Off. There are many other scenarios that it can protect your RV from, like overvoltage, under voltage, and voltage surges.
- Hardwired, 50 amp surge protector with blue tooth monitoring and...
- Smart Circuit Analyzer will shut down power to RV if a dangerous...
- Plug-n-play – Only 4 second delay power on after plugging in...
Limitations with 50 Amp to 30 Amp Plug Adapters
There are two drawbacks when using a 30A/50A adapter. First, using one of these adapters will significantly limit the power available to a 50 amp coach. This is because a 50 amp plug has 12000W potential, while the 30 amp plug only has 3600W. This makes it much easier to pop the 30 amp breaker, so you will need to limit your power usage.
Second, 50 amp plugs typically have 240V service, which will be unavailable with the adapter. This means if you have any 240V appliances (like a 240V washer/dryer unit), they will not work at all when using a 30A/50A adapter. However, most RVs do not use any 240-volt appliances so this is not usually a problem.
The solution to Popping 30 Amp Breakers
It’s an expensive solution, but one way to plug into any power source with a big rig is to install a hybrid inverter that passes power through it. With these inverters, you can set a shore power limit so you will not pop a breaker. The magic with hybrid inverters is that when you demand extra power, they will make it up from the RV batteries. When the excess load is removed, they will charge the batteries back up and you’ll never even know you exceeded that 20 or 30 amp circuit.
This is how our RV electrical system works. We have been plugged into 20 and 30-amp supplies many times and used our 50-amp RV like normal – never worrying about power. Our system is quite complex, but we’ve put together good explanations of how it all works. You can read about it here: Ultimate Off-Grid RV Solar Power System Build. Or, check out our YouTube video: Ultimate RV Off-Grid Solar System Build
Use an Auto Shut-Off Surge Protector to RV Safely In All Scenarios
In summary, you can plug your 30-amp RV into a 50-amp plug, and vice versa, you just need to make sure you know the limitations and how to do it safely. Again, we highly recommend using an auto-shutoff surge protector, like the Watchdog, to make sure you are protected near the plug at all times.
There are so many situations with RV park power that could damage your RV and having one of these devices in line will protect you. Besides, a device like the Watchdog will provide real-time monitoring information about your power usage and the line.
Overloading the electrical system on your RV can be dangerous and costly. But if you follow the guidelines outlined above when adapting your power supply, you will most certainly protect yourself and your investment!
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Sunday 19th of September 2021
I have a 2013 Coleman Dutchman . 29 R I have a question. I bought a 50 amp splitter , to go from 30 to 50 . I’m afraid it will damage the wires to my camper . But if I have air on and try to use the microwave my breaker pops . How/ can I remedy this and still be safe ? If by using a watchdog, Which one will I need to get?
Mortons on the Move
Thursday 23rd of September 2021
If your main breaker is popping it's protecting the cord outside. Unfortunately, 30 amp can only provide 3600 watts to the RV so an AC and microwave will frequently exceed that. The only way to remedy it safely would be to upgrade your main electrical box or add a second power feed with its own main breaker. Your RV is doing its thing to protect the wires, but if you did want the extra protection from the Hughes in case of a breaker failer you need the 30 amp with auto-shutoff version.
Sunday 15th of August 2021
Is the face on a watchdog supposed to be lit up white all the time? What if all four lights are green but the face is not lit up?
Mortons on the Move
Saturday 4th of September 2021
Only on the versions with the auto-shutdown, the face lights up. The version with the green lights it does not and that is correct.
Saturday 7th of August 2021
There is still a potential (a small one) problem when using a 50a to 30a adapter, even with a surge protector....anything between the 50a breaker and the surge protector. Does a 30a to 50a adapter only use one of the hot "legs" of the 5oa service? Have you ever seen a 240v clothes dryer in an RV? The only 240v use that I have seen are some older furnace.
Mortons on the Move
Saturday 4th of September 2021
That is correct, a 30-50 will only use one leg and bond them together. Thus a 240V appliance will not work. Yes we have seen 240V dryers in RV's but they are very uncommon.
Thursday 15th of July 2021
I am not an electrician, I am a retired builder, and like to understand things. I think I understand this, and I will try to explain what I have learned , and would appreciate knowing if I am thinking correctly. A 50a to 30a dogbone adapter works by leaving one hot wire out of the 50a (220v) dogbone adapter and is protected by the 30a breaker in the RV's EMS. A 30a to 50a dogbone adapter works by splitting the 30a (120v) hot wire current to 2-15a hot wires to each side of the 240-50a service wire. This works because the appliances in an RV are usually 120volts. A 15a + a 3oa to 50 amp adapter doesn't make sense to me, because an unbalanced current would not be good for some motors (I thought). The difference between a 15a and a 20a receptacle is not determined by wire gauge, but by the plug shape (a 20a plug has a vertical blade and a horizontal blade).
Mortons on the Move
Thursday 3rd of March 2022
Yep you have got it pretty well understood. Those 15+30 to 50A adapters are providing 120V to both sides of the breaker panel but will not provide 240V because they are on the same leg. Thus you would not actually have an unbalanced situation (and 240V is not used in the RV). You could pop that 15A breaker pretty easily in this situation however.
Thursday 17th of December 2020
Enjoying having just discovered your show and this website.
Do you think the Hughes Watchdog is a better or more sensitive surge protector than the Progressive Industries EMS-PT30X?
Thank you so much!
Mortons on the Move
Monday 21st of December 2020
Good question, I would not say that its any better in snuffing voltage spikes but it does have some advantages that I think make it better. First, it has a replaceable surge module so it does not give its life in the case of a big surge. The EMS should still work but will no longer protect the RV. Second, the Bluetooth information provided by the EPO watchdog version is so easy to understand and figure out what's going on. Seeing real-time information on your phone and being able to use it as a power meter is a great feature that is well worth the price in my opinion!