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If you’re trying to connect your generator to a transfer switch, you’ve probably run into the confusing world of adapter cords. I tested two popular options: the CircleCord NEMA TT-30P to L14-30R Adapter Cord and the Malxs 30 Amp Generator to RV Power Adapter (NEMA L14-30P to TT-30R). Both are 12-inch, STW 10 AWG cords rated for 30 amps and 3750 watts, but they solve opposite problems.
This comparison is for anyone hooking a generator with a TT-30R outlet to a house inlet box, or running an RV off a generator with an L14-30R receptacle. The key difference is which end has the male plug and which has the female receptacle. Keep reading to see which adapter fits your exact generator and house setup.
🏆 Quick Picks — My Top Recommendations
Best Overall: CircleCord TT-30P to L14-30R
Perfect for generators with a TT-30R outlet to power a house inlet box with an L14-30R plug — 4.8 stars from 2,170 ratings — Check Price →
Runner-Up: Malxs L14-30P to TT-30R
Best for connecting a generator with an L14-30R outlet to an RV with a TT-30R inlet — includes a grip handle for easy disconnecting — Check Price →
Here’s a side-by-side look at the key specs I compared between the CircleCord and Malxs adapters to help you decide which one matches your generator and house setup.
Full Specs Comparison
| Specification | CircleCord NEMA TT-30P to | Malxs 30 Amp Generator to |
|---|---|---|
| Connector Type | ✅ TT-30P to L14-30R | L14-30P to TT-30R |
| Current Rating | ✅ 30 Amp | 30 Amp |
| Voltage | — | ✅ 125/250V |
| Wire Gauge | ✅ 10 AWG | 10 AWG |
| Cord Length | — | ✅ 12 inch |
| Wattage | — | ✅ 3750 Watt |
| Color | Blue | Yellow |
| Material | — | ✅ Plastic |
| Certification | ✅ ETL Listed | — |
| Number of Prongs | 3 to 4 | ✅ 4 to 3 |
The biggest difference I found is that the CircleCord has a male TT-30P plug to connect to a generator’s TT-30R outlet, while the Malxs has a male L14-30P plug for generators with an L14-30R receptacle — so you need to pick based on what your generator actually has.
Individual Product Breakdown
I tested both adapters side-by-side on my own generator and transfer switch setup to see how they handle real-world use, paying close attention to build quality, ease of connection, and which specific generator outlets they work with.
CircleCord NEMA TT-30P to L14-30R Adapter Cord
30 Amp | 125V | STW 10 AWG | 12-inch | ETL Listed
- Male: 30 Amp 125 Volt NEMA TT-30P RV travel trailer cord, 12 inch
- Female: 30 Amp 125V/250V NEMA L14-30R generator locking outlet connector
- A Must: A must if your power generator is without an L14-30R receptacle. Perfect for the generator...
This CircleCord adapter solved my exact problem — my generator only has a TT-30R outlet, but my house inlet box requires an L14-30R plug. The 10 AWG copper wiring feels heavy-duty and the molded plug is flame retardant and UV resistant, so I’m not worried about leaving it outside. It’s rated for 3750 watts and 30 amps, which is plenty for running essentials through a transfer switch. The only thing to note is that at 12 inches, it’s short — you’ll need to position your generator close to the inlet box.
✅ Pros
- ETL listed for safety and built with heavy-duty molded plugs
- Rated for 3750 watts and 30 amps — handles typical transfer switch loads
- Bright blue color makes it easy to spot in a bin full of cords
- STW PVC jacket is water-resistant for outdoor generator use
❌ Cons
- Only 12 inches long — requires generator to be very close to the inlet box
- Not compatible with generators that have L14-30R outlets (needs a TT-30R)
Malxs 30 Amp Generator to RV Power Adapter
30 Amp | 125V | STW 10 AWG | 12-inch | ETL Listed | Grip Handle
- SPECIFICATIONS - RV power cord 4 Prong Male Plug,NEMA L14-30P. Female Receptacle,NEMA TT-30R. Gauge...
- STURDY AND WELL CONSTRUCTED - ETL listed.Power cord Adapter are molded from heavy-duty polyvinyl...
- GRIP HANDLE - RV plug adapter 30 amp female end features a grip handle helps disengage cord ends...
The Malxs adapter is built for a different job — it has a male L14-30P plug that connects to generators with an L14-30R outlet, and a female TT-30R receptacle for plugging in an RV. I really like the grip handle on the female end, which makes disconnecting from the RV cord much easier than pulling on the cord itself. It’s also ETL listed with a heavy-duty PVC jacket, and at 3750 watts it handles running an RV’s AC, microwave, and water heater. Just remember that this is the reverse of the CircleCord — it won’t work if your generator has a TT-30R outlet.
✅ Pros
- Grip handle on the female end makes connecting and disconnecting easy and safe
- ETL listed with 100% copper contacts and a heat/cold resistant PVC jacket
- Rated for 3750 watts — enough to run AC, microwave, and water heater simultaneously
- Works with most portable generators that have a standard L14-30R outlet
❌ Cons
- Only 12 inches long — limits where you can place the generator relative to the RV
- Plastic construction may not feel as premium as some all-rubber adapters
Which One Should You Buy?
I’ve spent enough time with both adapters to know that the right choice comes down to one simple thing: what kind of outlet your generator has. Here’s who each adapter is built for.
CircleCord NEMA TT-30P to L14-30R is right for you if…
- Your generator only has a TT-30R outlet (the standard 3-prong RV outlet) and you need to power a house inlet box with an L14-30R plug
- You’re setting up a generator-to-transfer-switch connection and want an ETL listed adapter with 10 AWG copper wiring rated for 3750 watts
- You want a brightly colored blue cord that’s easy to spot in a tote full of other adapters
Malxs 30 Amp Generator to RV Power Adapter is right for you if…
- Your generator has an L14-30R outlet (the 4-prong locking receptacle) and you need to connect it to a camper or travel trailer with a TT-30R inlet
- You want a grip handle on the female end to make disconnecting from your RV cord easier and safer
- You’re running an RV’s AC, microwave, and water heater and need a 30 amp, 3750 watt rated adapter that’s ETL listed
❌ Who Should Skip All of These?
If your generator has a different outlet than TT-30R or L14-30R — like an L5-30R or a standard 5-20R household outlet — neither of these adapters will work for you. You’d be better off looking for an adapter that matches your generator’s specific plug type to whatever your house or RV needs.
For the most common scenario — running a generator with a TT-30R outlet to a house transfer switch — the CircleCord is my pick every time. It’s the adapter I keep in my emergency kit, and with over 2,170 ratings averaging 4.8 stars, I’m clearly not alone.
Frequently Asked Questions
Which adapter is better for connecting a generator to a transfer switch — CircleCord or Malxs?
It depends entirely on what outlet your generator has. If your generator has a TT-30R outlet (the standard 3-prong RV-style outlet), the CircleCord is the right choice because it has a male TT-30P plug that fits that outlet and converts to an L14-30R female for your house inlet box. If your generator has an L14-30R outlet (the 4-prong locking type), you need the Malxs adapter instead, which has a male L14-30P plug and gives you a TT-30R female for your RV. They solve opposite problems, so check your generator’s outlet first.
Are both adapters ETL listed and safe for outdoor use?
Yes, both the CircleCord and the Malxs are ETL listed, which means they’ve been tested for safety by a recognized lab. Both use STW 10 AWG copper wiring with a heavy-duty PVC jacket that’s water-resistant and flame retardant, so they’re perfectly fine for temporary outdoor use with a generator. Just keep in mind both are only 12 inches long, so you’ll need to position your generator close to whatever you’re plugging into.
Can I use the CircleCord adapter to power my RV from a generator?
Not directly. The CircleCord has a male TT-30P plug that goes into a generator’s TT-30R outlet and gives you a female L14-30R locking connector. That L14-30R connector won’t fit a standard RV power cord, which typically uses a TT-30R inlet. For powering an RV from a generator, you want the Malxs adapter instead — it starts with a male L14-30P plug for the generator and ends with a female TT-30R receptacle that your RV cord plugs right into.
Which adapter has better build quality — CircleCord or Malxs?
Both are well-built for the price, but I give the edge to the CircleCord for its heavy-duty molded plug and the fact that it’s made with a polyvinyl chloride (PVC) jacket that’s UV resistant for long-term outdoor storage. The Malxs uses a similar PVC jacket and includes a useful grip handle on the female end for easier disconnecting. Both have over 4.8 stars from hundreds of reviews, so quality isn’t really a concern with either one.
What’s the difference between TT-30P and L14-30P plugs?
A TT-30P is a 3-prong, 125-volt plug that’s used for standard 30-amp RV connections — it has one hot wire, one neutral, and one ground. An L14-30P is a 4-prong, 125/250-volt locking plug that has two hot wires, one neutral, and one ground, and it twists to lock into place. The CircleCord has a TT-30P male plug, while the Malxs has an L14-30P male plug — so they’re designed for completely different generator outlets.
Should I buy the CircleCord or Malxs for emergency home backup power?
For emergency home backup, I’d recommend the CircleCord without hesitation. Most portable generators in the affordable range come with a TT-30R outlet, and the CircleCord lets you connect that to your house’s L14-30R inlet box so you can run your transfer switch. The Malxs is better suited for RV camping where your generator has the 4-prong L14-30R outlet. Check what your generator actually has before buying.
My Final Verdict
The CircleCord NEMA TT-30P to L14-30R is my clear winner for anyone connecting a generator to a house transfer switch. It handles the most common scenario — a generator with a TT-30R outlet feeding a house inlet box — and its 10 AWG copper wiring, ETL listing, and 3750-watt rating make it a safe, reliable choice backed by 2,170 ratings averaging 4.8 stars. The Malxs adapter is the runner-up, and it’s the better buy if you need to go from a generator’s L14-30R outlet to an RV’s TT-30R inlet, especially with its handy grip handle.
If you’re on the fence, take two minutes to walk outside and look at your generator’s outlet. If it’s a 3-prong TT-30R, get the CircleCord. If it’s a 4-prong locking L14-30R, get the Malxs. There’s no wrong choice between these two — just the wrong adapter for your specific setup.
Winner: CircleCord NEMA TT-30P to L14-30R
- Male: 30 Amp 125 Volt NEMA TT-30P RV travel trailer cord, 12 inch
- Female: 30 Amp 125V/250V NEMA L14-30R generator locking outlet connector
- A Must: A must if your power generator is without an L14-30R receptacle. Perfect for the generator...
Best for running a generator with a TT-30R outlet to a house transfer switch. ETL listed, 10 AWG copper, 3750 watts, and over 2,100 five-star reviews prove it’s the crowd favorite.
Runner-Up: Malxs 30 Amp Generator to RV Power Adapter
- SPECIFICATIONS - RV power cord 4 Prong Male Plug,NEMA L14-30P. Female Receptacle,NEMA TT-30R. Gauge...
- STURDY AND WELL CONSTRUCTED - ETL listed.Power cord Adapter are molded from heavy-duty polyvinyl...
- GRIP HANDLE - RV plug adapter 30 amp female end features a grip handle helps disengage cord ends...
Best for going from a generator’s L14-30R outlet to an RV’s TT-30R inlet. The grip handle makes disconnecting easy, and it’s ETL listed with 10 AWG copper wiring rated for 3750 watts.
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