I don’t think you can make that statement with such a small sample size. All you can definitively say is that airplane’s ports put out 30v.
Wilco062 on
Well yeah? Those aren’t meant to be real wall outlets, more like a weird halfway step between a charger port and actual AC power.
I mean it’s common sense, you may have 200-300+ of those in a plane… You’re flying in the air, you’re not connected to a grid… Lower voltage runs cooler so it’s safer inside a cramped seat shell or bulkhead. It reduces stress on the aircraft electrical system and it stops people from trying to plug in hair dryers or kettles at 40,000 feet.
otherbound14 on
And it’s wired wrong
Party-Woodpecker-601 on
Funny thing is they’ll still charge a phone fine, but anything bigger just gives up immediately.
Enlitenkanin on
Airplane outlets really said we’ll keep your phone alive but forget about powering a toaster.
WutzUpples69 on
How many amps?
No-Home8878 on
So basically, airplane outlets are just strong enough to keep your phone alive, but not your hopes and dreams.
DesperateAdvantage76 on
That meter might not work with those crappy dc-ac inverters that aren’t true sine wave output. Not a big deal on a plane since it feeds back into dc adapters.
CheeseSteak17 on
You may want to have that meter looked at. The AC power for passengers is 110V. Devices aren’t going to work with 30VAC.
heyo_1989 on
How many amps?
metrawhat on
doll-haus on
Is this voltage meter going to work correctly? AC voltage meters do some math to find the RMS, and I *believe* airplane *frequencies* are far higher (400hz).
aircooledJenkins on
That… Might explain why airlines don’t let passengers plug in their cpap machine.
starwyo on
Are you my brother? He’s always testing outlets everywhere we go.
armathose on
According to your plug tester on an inversion system.
I know it’s most certainly not 30VAC other wise I would not be able to charge certain items. In fact many power supplies would not output DC voltage at that level.
fatleech on
Those plug testers can lie about voltage all day long, probably open hot with phantom voltage induced from sharing long raceways with other live circuits
No-Control6483 on
I mean if everyone had something plugged in it’s definitely going to slow it down
zrowett on
To be fair, I think I’d rather have majority of the power concentrated on just staying airborne when it needs to anyways.
Deemaunik on
I mean… it’s a plane. And there’s probably 400+ seat outlets on a 747. Plus screens, lights, gadgets, air conditioning… that’s a lot of power.
DrLimp on
That’s not a true RMS meter and will not give an accurate result since probably the inverter is not giving you a pure sine wave ac. Same thing if you use to probe the power out of an UPS for computers.
-Big-Goof- on
Hey be careful those things have been known to dry phones.
Always bring a power Bank or twoÂ
ColdOn3Cob on
I’m sorry the electricity output of the chairs within the flying metal tube isn’t strong enough for you or whatever.
futurebigconcept on
35 volts, more or less, is the lower threshold for stopping a human heart by electrocution.
OmegaKitty1 on
Clearly incorrect as they power laptops perfectly.
Or you only tested one aircraft type. But no way this is accurate generally.
Your tester is likely busted
PerepeL on
Imagine plugging in your macbook charger and immediately hearing the engines humming tone slightly shift.
Altilla on
Might just be a grounding reference issue between the outlet and the meter. Aircraft AC systems use a floating neutral, so if your meter doesn’t have a solid reference to ground, you’ll see weird partial voltages. Same thing happens with control transformers when the secondary neutral isn’t bonded the meter has nothing stable to reference, so the voltage comes out low or inconsistent.
clarkcox3 on
It’s more likely the tester.
freejus on
AC voltage on an airplane is 400hz.  Probably screwing with your meter.  Use a real multimeter and you’ll see 115vac.  DC within the seats is typically seen at 28vdc.
I troubleshoot these systems for a living.
Edit: you’re using a GFCI tester.  Derp.
Classic-Kitchen1856 on
Could also be that the outlet was disabled and the tester is just detecting residual charge. Airplane power can be hit or miss depending on the row.
chaseonfire on
You aren’t going to get a correct reading like in a building with a working ground grid. If the outlet was actually 30 volts nothing would work properly.
Michaeli_Starky on
Looks like a malfunction in the outlet or in the device that you use. Most likely the outlets doesn’t output a true sine and your device can’t read it properly.
icedchailatte22 on
Hit the test button
Cuddle-sheep on
That’s 200 volt short.
iDontRememberCorn on
No.
It’s 110-120v, guaranteed.
justinDavidow on
Many modern plane inverters do load sensing by passing a low voltage at very low potential current and waiting for current to start being drawn, then ramp up the load and voltage. (I’ve seen this done at the “row” level, but not yet at the seat level; the seats in a single row typically share a single wire pair back to the inverters)Â
Today this saves: energy, fuel, and ultimately cost for everyone.
Bonus, because most planes dont have nearly 100% of passengers using the outlets, the inverter can typically be “oversubscribed” somewhat, allowing further savings.Â
What you’re likely seeing here is that sense voltage.  Try plugging a load into the other outlet and test again.Â
roadstojudah11 on
Better than nothing
deflorist on
SAD
Kroadus on
Proof that buying a tool doesn’t make you an electrician.
CoBudemeRobit on
I noticed that when I was playing a game on my laptop it stopped charging when a more challenging game was launched
Grolschisgood on
Couple of coments as an aeronautical engineer that does a fair bit of electrical work in various aircraft types. Firstly, if only 30VAC was being provided nothing plugged into it would work. What is quite common though with inverters, the device that converts the voltage from dc to ac, is that they arent true sinewave inverters as they are far more expensive and heavy. Instead its a stepped approximation of a sinewave. I pretty much exclusively install sinewave inverters as I am involved in the aeromedical industry and its actually really important as sensitive devices often dont work correctly. What I imagine is happening here is that your device isnt sampling at a high enough frequency to measure the voltage correct or the stepwise voltage change is messing with the device and its confusing that with the oscillating 60Hz that would typically be expected. Fundamentally its this frequency issue that causes lots of the sensitive medical device to not work properly and im certain thats what’s going on here too. Something like a laptop, pretty much the only device that would get plugged into them is a lot more robust in that respect since it has a power brick that converts the AC power back into DC. Being an inverters itself its able to take far rougher power and convert it appropriately.
41 Comments
I don’t think you can make that statement with such a small sample size. All you can definitively say is that airplane’s ports put out 30v.
Well yeah? Those aren’t meant to be real wall outlets, more like a weird halfway step between a charger port and actual AC power.
I mean it’s common sense, you may have 200-300+ of those in a plane… You’re flying in the air, you’re not connected to a grid… Lower voltage runs cooler so it’s safer inside a cramped seat shell or bulkhead. It reduces stress on the aircraft electrical system and it stops people from trying to plug in hair dryers or kettles at 40,000 feet.
And it’s wired wrong
Funny thing is they’ll still charge a phone fine, but anything bigger just gives up immediately.
Airplane outlets really said we’ll keep your phone alive but forget about powering a toaster.
How many amps?
So basically, airplane outlets are just strong enough to keep your phone alive, but not your hopes and dreams.
That meter might not work with those crappy dc-ac inverters that aren’t true sine wave output. Not a big deal on a plane since it feeds back into dc adapters.
You may want to have that meter looked at. The AC power for passengers is 110V. Devices aren’t going to work with 30VAC.
How many amps?
Is this voltage meter going to work correctly? AC voltage meters do some math to find the RMS, and I *believe* airplane *frequencies* are far higher (400hz).
That… Might explain why airlines don’t let passengers plug in their cpap machine.
Are you my brother? He’s always testing outlets everywhere we go.
According to your plug tester on an inversion system.
I know it’s most certainly not 30VAC other wise I would not be able to charge certain items. In fact many power supplies would not output DC voltage at that level.
Those plug testers can lie about voltage all day long, probably open hot with phantom voltage induced from sharing long raceways with other live circuits
I mean if everyone had something plugged in it’s definitely going to slow it down
To be fair, I think I’d rather have majority of the power concentrated on just staying airborne when it needs to anyways.
I mean… it’s a plane. And there’s probably 400+ seat outlets on a 747. Plus screens, lights, gadgets, air conditioning… that’s a lot of power.
That’s not a true RMS meter and will not give an accurate result since probably the inverter is not giving you a pure sine wave ac. Same thing if you use to probe the power out of an UPS for computers.
Hey be careful those things have been known to dry phones.
Always bring a power Bank or twoÂ
I’m sorry the electricity output of the chairs within the flying metal tube isn’t strong enough for you or whatever.
35 volts, more or less, is the lower threshold for stopping a human heart by electrocution.
Clearly incorrect as they power laptops perfectly.
Or you only tested one aircraft type. But no way this is accurate generally.
Your tester is likely busted
Imagine plugging in your macbook charger and immediately hearing the engines humming tone slightly shift.
Might just be a grounding reference issue between the outlet and the meter. Aircraft AC systems use a floating neutral, so if your meter doesn’t have a solid reference to ground, you’ll see weird partial voltages. Same thing happens with control transformers when the secondary neutral isn’t bonded the meter has nothing stable to reference, so the voltage comes out low or inconsistent.
It’s more likely the tester.
AC voltage on an airplane is 400hz.  Probably screwing with your meter.  Use a real multimeter and you’ll see 115vac.  DC within the seats is typically seen at 28vdc.
I troubleshoot these systems for a living.
Edit: you’re using a GFCI tester.  Derp.
Could also be that the outlet was disabled and the tester is just detecting residual charge. Airplane power can be hit or miss depending on the row.
You aren’t going to get a correct reading like in a building with a working ground grid. If the outlet was actually 30 volts nothing would work properly.
Looks like a malfunction in the outlet or in the device that you use. Most likely the outlets doesn’t output a true sine and your device can’t read it properly.
Hit the test button
That’s 200 volt short.
No.
It’s 110-120v, guaranteed.
Many modern plane inverters do load sensing by passing a low voltage at very low potential current and waiting for current to start being drawn, then ramp up the load and voltage. (I’ve seen this done at the “row” level, but not yet at the seat level; the seats in a single row typically share a single wire pair back to the inverters)Â
Today this saves: energy, fuel, and ultimately cost for everyone.
Bonus, because most planes dont have nearly 100% of passengers using the outlets, the inverter can typically be “oversubscribed” somewhat, allowing further savings.Â
What you’re likely seeing here is that sense voltage.  Try plugging a load into the other outlet and test again.Â
Better than nothing
SAD
Proof that buying a tool doesn’t make you an electrician.
I noticed that when I was playing a game on my laptop it stopped charging when a more challenging game was launched
Couple of coments as an aeronautical engineer that does a fair bit of electrical work in various aircraft types. Firstly, if only 30VAC was being provided nothing plugged into it would work. What is quite common though with inverters, the device that converts the voltage from dc to ac, is that they arent true sinewave inverters as they are far more expensive and heavy. Instead its a stepped approximation of a sinewave. I pretty much exclusively install sinewave inverters as I am involved in the aeromedical industry and its actually really important as sensitive devices often dont work correctly. What I imagine is happening here is that your device isnt sampling at a high enough frequency to measure the voltage correct or the stepwise voltage change is messing with the device and its confusing that with the oscillating 60Hz that would typically be expected. Fundamentally its this frequency issue that causes lots of the sensitive medical device to not work properly and im certain thats what’s going on here too. Something like a laptop, pretty much the only device that would get plugged into them is a lot more robust in that respect since it has a power brick that converts the AC power back into DC. Being an inverters itself its able to take far rougher power and convert it appropriately.
Wrong.