Dear Mike,
My question isn’t as technical as the others… so here goes. I live full-time in my 38′ 5th wheel toy hauler with a 50-amp shore power connection. It also has an Onan 4400 generator if I need it. Where I’m parked, it is switching from flat-rate electric to metered. The pedestal has both 50-amp and 110-volt plugs. Is it cheaper to use the 110 with an extension cord for small appliances and microwave? Only one at a time—I unplug things I’m not using. Unless it’s a fan. Thank you for your time. —Christie
Dear Christie,
That’s a great and timely question. The quick answer (for those of you who don’t want to read the full explanation) is no, it doesn’t matter which receptacle you plug into. You can plug a 120-volt appliance into one of your RV’s internal outlets and you’ll use exactly the same kWh (kilowatt hours) of electricity compared to plugging the same appliance directly into the 20-amp outlet on the pedestal.
Just like for your sticks-and-bricks house, the entire panel is being metered for kWh usage. So everything plugged into an outlet in your house (or in your case, the pedestal) will be metered (and billed to you) exactly the same amount.
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How does this work?
Here’s a basic wiring diagram of how the 50-amp shore power outlet in the pedestal is split up into the various appliances and electrical systems in your RV.
The pedestal supplies your RV with two separate 120-volt legs which are 180 degrees out of phase with each other. That allows the power panel to be wired to supply either 120 or 240 volts to the load.
However, in nearly every RV on the road, the power panel is wired to supply ONLY 120-volt loads. So that’s one hot leg plus the neutral conductor feeding each air conditioner, battery converter, and all 20-amp electrical outlets in your RV. There are a few exceptions for large coaches wired with 240 volts, but these are pretty rare birds.
What is the meter measuring?
The metered pedestal is measuring the TOTAL amount of electrical energy (kWh) passing through the entire pedestal circuit. So it doesn’t matter if you plug into the 50-amp outlet, the 30-amp outlet, or the 20-amp outlet. If you used 10 kWh of energy, and they’re billing you at 15 cents per kWh, then you’ll owe $1.50 for that usage. And again, it doesn’t matter if you plug your slow cooker into the pedestal directly or an outlet inside of your RV. The meter only sees the TOTAL amount of energy passing through the pedestal.
How can you reduce your energy bill?
First of all, forget about any of the scam devices on the market that say they can reduce your electric bill by up to 85%. First of all, if that were true then you would be stealing electricity from the campground. And that’s a bad thing you never want to do. But be assured they don’t work anyway, so save your money.
Just like in your sticks-and-bricks house, you can do a number of things to help reduce your electric energy costs.
Park in the shade if you can. That’s not always possible, but that will certainly reduce the load on your air conditioner.
Forget about the air fryer. While these work great, they typically draw around 1,500 watts of power for 20 or more minutes at a time. So every air frying session could cost you up to 1 kWh of energy. Depending on the local rate, this could cost you between 15 cents and 50 cents every time you make those tasty no-fat fries.
Turn off your water heater. If you only need hot water for showers in the morning, then don’t leave the water heater on all day and night. Turn it on an hour or two before you need it, then power down.
Turn off your air conditioner when you leave. I see lots of unattended RVs with air conditioners running and windows open at the same time. Yes, I can understand that if you have a pet inside you’ll need the air conditioner during the day, but I’ve checked and that’s not usually the case.
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Learn how to save…
There’s a LOT more ways to save on electrical power usage. You just need to use your head and see what you’re wasting.
One of the easiest ways I’ve seen to monitor your own energy usage is the smartphone app for the Hughes Power Watchdog surge protector. This not only shows you instantaneous voltage and amperage your RV is using, it also adds up the total kWh usage for your entire RV. That means you can turn on one appliance at a time and see just how many amps and kWh it takes. Then you can decide if it’s worth the expenditure.
Some of the big ticket items are portable electric space heaters and electric fireplaces. These can easily add $100 to your electric bill each month, so you’ll want to find better ways to keep warm in the winter.
Let’s play safe out there….
Send your questions to me at my new RVelectricity forum here.
Mike Sokol is an electrical and professional sound expert with 50+ years in the industry. His excellent book RV Electrical Safety is available at Amazon.com. For more info on Mike’s qualifications as an electrical expert, click here.
For information on how to support RVelectricity and No~Shock~Zone articles, seminars and videos, please click the I Like Mike Campaign.
##RVT1050
The highest we’ve paid for electricity was in Florida last winter, 16 cents per KWH. The highest monthly bill was $128 and we have two air conditioners and a dog, an electric water heater (1,440 watts), an RV fridge (400 watts), an Instant Pot, and a Splendide combo washer/dryer that we use almost every day, especially on Dry for bath towels (1,300 watts maximum). And occasionally a 750 watt space heater and/or the 1,500 watt fireplace for heat when it got cold at night. Heck, that electric bill for the month won’t even buy me 35 gallons of gas. It’s all about perspective. 🙂
Funny. Right under your article and after you said forget about those scam devices there is an ad for a scam device – Electric-Saver.com. At least on my computer. You can save up to 90%.
Thanks, Larry. That’s why, for the ads in the middle of the content, we’ve put the caveat that they are auto-inserted by Google. Now I know to put that caveat at the very bottom of the post, also. Sometimes folks think that if there’s an ad for a product in Mike’s post, it means he endorses that product. Sometimes he might, but we never know what’s going to pop up, like this scam device you saw advertised. Thank you for the good idea! Have a great day. 😀 –Diane
Hi Larry,
We try to block these scam device ads, but it’s like playing whack-a-mole. They just pop back up again! Grrrrr.
I’ll head over to our ad dashboard and ban them again.
-Kim
Sadly, Google automatically inserts ads based on scanned content. So when I write about scam devices, up pops ads for the very devices I’m warning you about…
Interesting how many people (rv’ers) who are ignorant of electricity…even the basics. Case in point the OP indicated a 50 amp outlet and a 110 volt outlet. The 50 amp outlet is two legs of 120v/50amp whereas the 110 volt outlet is actually 120v/15amp outlet. They are both 120vac. Granted one can use “110” in place of the actual “120” due to misinformation and what use to be common usage and therefore we, the readers, know what the OP was actually referring to.
It used to be 110 volts, then was raised to 115 volts, and now is 120 volts nominal.
Thanks Mike for the history on voltage. I knew it could read anywhere in that range but didnt know the official voltage is 120 in USA. Other countries too ?
We found a way to reduce our electric consumption. We installed the Victron Multiplus II. (Its part of our solar system) We can adjust the maximum Current (Amps) we want to draw off the pedestal at anytime. If we draw more than the setpoint, the Multiplus will “assist” with the batteries. The batteries recover their loss with the solar panels. Of course this is great for daytime use. If after dark, the batteries would recover using the built in convertor. (battery charger) thus using pedestal power.
If you plug that 110 into your neighbor’s pedestal, I’ll bet your bill will go down! 🙂
Hahahahahahaha!
Bruce, you beat me to it.
Glad to see the mention of Hughes Watchdog. We really like ours. The monitoring is very helpful especially when using an extra electric heater. We could tell when we were close to 30 amps. The unit shut off preventing any overage. Best, I can restart the electric from my phone after turning off an appliance or the unit would restart automatically.
We found that living in our trailer for months, our electric bill used about $30 a month and that’s with electric WH and space heater use some nights.
Well, plugging into the pedestal will avoid the resistance of the wiring in the RV. Maybe 1 or 2% difference. If your cable is going bad it may be a bit more (if it gets hot replace it). If you are going to be outside or inside the whole time it won’ t make much difference. If you are going to be in and out a lot, you are going to drive up your A/C usage more than the savings.
Interestingly, that extra 1% voltage drop inside of your RV will actually reduce the amperage draw and kWh usage from resistance heaters and cooking appliances. So it pretty much evens out…