By Russ and Tiña De Maris
For some new to RVing, electricity is a mysterious force — one difficult to sort out. Here’s an example: “My RV has a 30-amp connector. I want to plug it in at home but I only have a typical outlet — 20 amps, I think. Will it hurt to plug my RV in and use it? And how can I do it?”
The answer isn’t a straight “yes” or “no,” because so much depends on what electrical-consuming appliances you’ll want to use in your RV. Plugging an RV into a “smaller” circuit simply requires the appropriate adapter. You’ll find these at any RV parts outlet, at many Walmart stores, and at Amazon. Not only does this apply to a “30-amp-loving RV,” but to 50-amp-wired RVs as well.
What happens when you plug that “bigger” drawing plug into a “smaller” circuit simply means you have less available power. You’ll probably be able to use most (if not all) of your appliances and other power consumers, but you won’t be able to use them all at once.
The big power consumers — air conditioners and water heaters with electric option, for example — will have to learn how to share — run one biggy, shut it off, turn on another. Most other stuff, like lighting, fans and water pump, will all probably be happy to coexist and operate at the same time. You’ll know if this isn’t the case when the breaker serving the power outlet you’re plugged into trips and plunges you into the outer darkness.
But a BIG word of caution: Never try to “extend your reach” when using a setup like this with the addition of an extension cord to your rig — it adds one more layer of “resistance” to the mix and could get you in trouble. It’s also wise to have an inexpensive line voltage meter plugged in and monitoring. For less than $20 you can buy one that plugs into one of your RV’s power outlets, and a quick glance will tell you how much voltage is reaching your rig. If it drops below 110 volts, it’s time to turn a few things off, as low voltage can readily kill some items — like air conditioner motors. Amazon has a selection of voltage meters.
What about “adapting up,” the other way? Say you have a 30-amp plug on your RV and the only available power outlet is a 50 amper? In this case, you’ll have plenty of power available for your needs — you’ll simply need the appropriate adapter. There’s no need to worry that you could have “too much power.”
photo: public domain image from wikimedia.org
I know this is an old article, but shouldn’t it state that all 240V appliances in a rig that usually requires 50Amp service won’t operate if an adapter is used to deliver 30Amp or 20Amp (both 120V only)?
Unless you have a large coach, typically all RVs with a 50-amp shore power connection only have 120-volt appliances. So a 20 or 30-amp to 50-amp adapter will send 120-volts AC to both legs properly and everything will operate.