Why doesn't the US switch to from 120v to 240v

[mikescooling]

So were having power issues, with a growing population using more power. Then the ever popular coal vs nuke power plant debate. This thread is asking, why don't we start switching everything to 240v? Why or why not?

 

[Hammy71]

Logistics. Over a hundred years of appliances, lamps, doodads of every sort are 120v. Every house is wired for 120v convenience outlets and lighting. Would cost way to much money to justify the savings. Someday the ROI might make sense, but not in the foreseeable future.

 

[bu_gee]

Nobody changes things for the sake of changing them. You misunderstand electrical transmission if you think converting to 240v will make any difference.

Also, things that need 240v already get it.

 

[Billy-Klubb]

everyone needs a Lincoln Power Wave in their kitchen.

 

[brew_ny]

Nobody changes things for the sake of changing them. You misunderstand electrical transmission if you think converting to 240v will make any difference.

Also, things that need 240v already get it.

like that 7200 volts on pole being stepped down to 120/240 by the transformer ?

 

[AnOldUR]

480!

 

[mikescooling]

To those angry posts, you know 240v uses about 1/2 the power of 120v. You could then change over the outlets and start buying 240v stuff. The only thing in life that is constant is change.

 

[ChemEng]

To those angry posts, you know 240v uses about 1/2 the power of 120v. You could then change over the outlets and start buying 240v stuff. The only thing in life that is constant is change.

It will use 1/2 the amperage but at 2x the voltage, so it will use the same amount of power. Unfortunately this is not the solution to the power problem.

 

[schiersteinbrewing]

same reason we haven't gone to the metric system.....it requires change

 

[Zepth]

To those angry posts, you know 240v uses about 1/2 the power of 120v. You could then change over the outlets and start buying 240v stuff. The only thing in life that is constant is change.

Well actually, no. The line loss rate is minimal since the high voltage lines do most of the work and they wouldn't change anyways. V * A = W. Double the voltage and in a perfect world you'd double the wattage keeping amperage the same. My power bill charges by the watt.

What would change would be an increase in efficiency, depending on the application. See the attached image. It's not a groundbreaking achievement and certainly won't justify the upgrade cost. If you happen to be renovating and can put 240 into the computer room for the tower go for it! I would, but I also have a comically overpowered computer. For the vast majority of people they wouldn't notice any difference.

 

[brew_ny]

To those angry posts, you know 240v uses about 1/2 the power of 120v. You could then change over the outlets and start buying 240v stuff. The only thing in life that is constant is change.

so if my well pump at 240 volts draws 5 amps and at 120 volts draws 10 amps

but is a 1500 watts an hour pump and I buy my power by the kilo watt

it is still using the 1.5 kilo watts of power an hour on 120 or 240, so I am not getting the half the power statement

all the best

S_M

 

[CJ1]

so I am not getting the half the power statement

all the best

S_M

Not going to happen. The power company doesn't save any money switching you to 240v, so your bill isn't going down at all.

 

[mikescooling]

I thought their was a small savings from using 240v and now that you mention it most of the stuff, electric stove, A/C, brew room, and Hot tub already has a 240v plug. Would it be cheaper in new construction to install the 240 option?

 

[brew_ny]

The power company doesn't save any money switching you to 240v,

nor do I

 

[doug293cz]

Safety is also a concern. I've "tickled" myself a number of times over my 60+ years (most in the first 30) on 120V mains. Not sure I'd still be here if the houses I grew up in had 240 in all the outlets.

Brew on

 

[bu_gee]

Safety is also a concern. I've "tickled" myself a number of times over my 60+ years (most in the first 30) on 120V mains. Not sure I'd still be here if the houses I grew up in had 240 in all the outlets.

Brew on

I've zapped myself on 240V when in other parts of the world. It definitely tickles harder, but I don't think I was out of sorts for that much longer afterwards.

 

[Billy-Klubb]

but are we getting Lincoln welders in our kitchens?!?

 

[podz]

Safety is also a concern. I've "tickled" myself a number of times over my 60+ years (most in the first 30) on 120V mains. Not sure I'd still be here if the houses I grew up in had 240 in all the outlets.

I've been hit by 25 thousand volt charges thousands of times in my life, no damage done.

Voltage doesn't kill, current does. Large current doesn't usually kill, either. It's a specific range of tiny current that you need to worry about. The lethal current is between 100 and 200 milliamps.

 

[doug293cz]

I've been hit by 25 thousand volt charges thousands of times in my life, no damage done.

Voltage doesn't kill, current does. Large current doesn't usually kill, either. It's a specific range of tiny current that you need to worry about. The lethal current is between 100 and 200 milliamps.

Yep, if the high voltage supply has very low current capability then you are likely to get a big thrill, but no damage. This is why static shocks are usually harmless... minimal charge storage and therefore low current capability. If it can put out more than a few milliamps, then you can be in trouble. Normal household wiring circuits (10 - 50 amps) definitely have enough milliamps to kill you, so it becomes a question of what your electrical resistance is, and if I = V/R is a big enough value to toast you. If your R is constant, then doubling the V will double the I. That's why low voltage circuits are safer. It's tough to get enough I with the R of the human body to do any damage.

Brew on

 

[bu_gee]

Realistically speaking, you need a couple mA across your heart for a potentially fatal scenario. However, electricity far an above prefers flowing on the surface of your body because the moisture on your skin is the path of least resistance, quite literally. Not that it can't happen and it does; it is just very rare even at 240v.

The bigger danger is burns from the contact. 240v by its nature transfers 4 times the power at the same resistance as 120v. All other things being equal, a 240v burn would be 4 times as bad.

 

[MaddBaggins]

but are we getting Lincoln welders in our kitchens?!?

I'm going with the Miller option.

 

[Billy-Klubb]

I'm going with the Miller option.

you made Bob angry.

 

[MaddBaggins]

you made Bob angry.

Bobs last name ain't Miller, is that it?


Sent from my magic box, using only my thumbs.

 

[MaddBaggins]

I got one of these. Sure would look good next to the stove.




Sent from my magic box, using only my thumbs.

 

[Billy-Klubb]

Bobs last name ain't Miller, is that it?


Sent from my magic box, using only my thumbs.

it would be Klubb.

personally I prefer pipe welding with a Lincoln Classic 300, but not much call for that sort of thing in my area. as for wire, I'll run just about anything. I learned on an ESAB and run both Lincoln and Miller. all three are fine by me!

 

[illinoisbrassman]

<iframe width="560" height="315" src="//www.youtube.com/embed/lcGDa9KpjMw" frameborder="0" allowfullscreen></iframe>

 

[Zepth]

Interesting. I'm still partial to my engine block / exhaust manifold Pogos. 40 minutes at 100km/hr, crispy on the outside warm and delicious on the inside.

I still take my place in line behind this guy:

 

[Airplanedoc]

Because Thomas Edison said so in 1880.

 

[TasunkaWitko]

Same applies to 120/240 debate.

 

[brew_ny]

Because Thomas Edison said so in 1880.

if it was up to Edison we would be using DC, George Westinghouse/Nikola Tesla gave us AC