What?
Home charging 110 vs 240 - Efficiency?
- Thread starter JeffKeryk
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He must have changed the outlets in his house to 240 instead of 120. Electric motors that can do 240 or 120 actually last longer at 240. Many power supplies have switches where you can run it at 240/120, all you need to do is flip the switch on the power supply. Relatively simple to do a 240 volt outlet, all you need is a double pole 20 amp breaker. Instead of a hot, neutral and ground wire, you just have two hot wires and a ground wire and it's the same size outlet, just a different looking plug. I did that for a treadmill, most gyms dump their old ones after a few years and many of them are 240 and they're cheaper than the 120 volt treadmills. You could pick up a 7k treadmill for about 1k or less and that is way sturdier than any home brand 120 volt treadmill.
Good point! I would run a dedicated circuit, and if doing that anyway, might as well make it 240.
Yes, apparently Edison used to play up the dangers of AC, and suggested that criminals be "Westinghoused" to death with AC.
It's interesting, though, that HVDC (high-voltage direct current) is a very efficient way to transport electricity. There is huge capital cost, though, in establishing converter stations at each end (AC to DC at the generation end, and DC to AC at the load end).
I put a subpanel in my garage so I have both 240V and 120V dedicated circuits. Wasn't that much more expensive to do that.
Yes, you can use the same Romex wiring. You basically have two sine waves at 120 volts and when you add two sine waves together you double the voltage. With a hot and a neutral, you just get the 120. The Romex isn't carrying any extra voltage, just two hot wires instead of one hot wire. In this case, it would be a 20 amp double pole breaker.
As for why 120 instead of 240, houses are wired for 240 at the panel. There's 3 wires coming in, two hot wires and one ground. At the panel, there's 240, the two hot wires on each pole. You can either tap 120 or 240 depending on what you need.
okay so then it would be a matter of updating the individual breakers, every outlet and fixtures (light bulbs, ceiling fans, hand held appliances, etc)
How does this impact power usage? Less power with the 240V system?
No it’s the same amount of power, you don’t get anything for free. But the current is cut in half so you can use a smaller wire gauge which is less expensive. But if the wire is already run you’re not going to recoup anything in that regard.
OKay. Zee09 implied that because he went 240V that is electric bill was next to nothing so I was confused. BTH I don't remember much about electricity.
Yes and he was informed that his implication was faulty. The electric meter measures power (watts) so its independent of the voltage being used.
I think it's politics, national pride etc.
I'm not sure they hated each other's guts. Tesla worked for Edison for awhile. Tesla invented the AC that we all use today while Edison gets all the credit. Tesla was a brilliant idea guy but couldn't put thoughts into action. Edison was good at implementing ideas to the real world. Tesla would have been one of the richest men in the world if Westinghouse had not screwed him. He was originally supposed to get a cut of every house that was wired. Edisons idea would require a power plant every few blocks. I'm a few miles from Edison's winter home in Ft Myers. It's a very interesting place to visit. There are some original phonographs there they they demo for you and some of them sound good by today's standards.
Motors tend to last longer at the higher voltage than the lower voltage. But a kilowatt is a kilowatt no matter what the voltage is. I would actually have to see the specs of the equipment to say whether or not it's using less power and the amount you're really saving. You do have a limited number of breaker slots and it's not that easy finding everything to run at 240.
Didn’t Tesla die in a hotel very poor or something? If he did become the richest man in the world, the outcome is the same.
Tesla didn't have the business acumen to get/ stay rich off his inventions. Some of his inventions were also... impractical. Like broadcasting free electricity through the air.
Edison knew how to make a buck. He was great pals with Henry Ford and Harvey Firestone.
Edison knew how to make a buck. He was great pals with Henry Ford and Harvey Firestone.
He said he pays nothing (someone else is paying), not that electricity use is zero.
He did? Guess I missed that part, I looked back and don't see that part. What I read was:
So I took that to mean that his use of a higher voltage reduced his power to "nothing."
I guess I misread then.... Maybe he blew his machine tools so it won't work.
I presumed that Zee09 was joking when he posted that he ran everything on 240 V.
Although ... I know someone who installed a 240 V receptacle in his kitchen here, supplied by #12 AWG (good for 16 A continuous). He then bought a Brit 240 V kettle, and changed out the Brit plug to a North American one. He's able to boil water very quickly. That's fine for a load designed to be run on 240 V, but it would be expensive to replace all of your electric tools, lamps, appliances, stereo, etc., with 240 V units.
And why not just put a 240 V plug on a 120 V kettle? Let's do the math ...
P = IV
1500 W = I*240 V
I = 1500 W/240 V = 6.25 A
I = E/R
6.25 A = 120V/R
R*6.25 A = 120 V
R = 19.2 Ohms
Now let's change the voltage to 240 V.
I = 240 V/19.2 Ohms = 12.5 A
We've doubled the current - it's unlikely the element will withstand double the intended current. The 3000 W Brit kettle was designed to run at 12.5 A. The 1500 W North American one was designed to run at 6.25 A. It might work, but why risk it? And surely any indicator light on the kettle would burn out quickly at twice the intended voltage.
For what it's worth, during our year in New Zealand I listened to a rant from an expat Brit who said that the only reason North American uses 120 V (instead of 240) is that the American robber barons bought up the copper mines and then pressured the legislators to standardize on 120 V so as to maximize copper usage.
Personally, I've always assumed it was for safety; 120 V will give you a non-lethal poke, whereas 240 V can really hurt you.
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