Rotary Phase Converter (Create 3-phase power from a single phase source)

[nhengineer]

Junker,

In my opinion we are saddled....

Paul, the first incorrect assumption you made is that electric service in the USA is 115/230V. Wrong. If you want 115V (I cannot imagine why you would) you would need a buck transformer. 125/250V is pretty much standard from generating stations in most metropolitan USA locations. By the time it gets to your house or shop, losses could have taken away as much as 10% giving you 112.5/225V but that is highly unlikely unless you live way way out in the boon-docks.

Intending no disrespect but the rest of your manifesto is equally inaccurate. I only mention this, not to embarrass you, because there are some folks out there the may believe it and that could be dangerous for them.

Thank you.

[Paul Alciatore]

Oh for gosh sake! The electric Voltage in the US has been specified, stated, and generally assumed to be anything from 110/220 to 130/260 Volts or even more. It is not and never has been any exact figure and I have seen various specifications put forth by different power companies in different regions/states. Many people simply say 110/220 Volts. Nameplates on appliances generally show a number between 110 and 120 VAC but they can show other values. 230 Volts is a commonly used number for motors: I can not remember seeing even a single nameplate that used the 250 Volt number but I would not be surprised if there were some. For a time 117 VAC was a commonly used number, probably a compromise due to the confusion. And 117 is approximately half way between 110 and 125 and that range is generally assumed to be where most power lines and most appliances will exist. Most, dare I say all appliances and devices sold in the US WILL work just fine on any Voltage in the range from 100 to 130 Volts or perhaps more.

I have measured the line Voltage on many occasions and always get a different figure. And it can vary during the duration of a single day. Just for fun I cranked up my best digital meter and measured the line here at my desk. It was 126.4 V. So what? It will be different tomorrow morning or at midnight or next week. It is probably different for different houses on my block that are on the same pole transformer as the copper losses will be different to each one. I would likely get a different reading if I took that same meter to my bedroom or garage/shop. Oh, and in one location where I had line Voltage monitoring equipment I have seen the line Voltage go as low as 85 Volts or so. An aluminum processing plant had their furnaces on the same feeder and when an additional one came on line, the Voltage really dropped until the local utility was able to bring more capacity on line. Sometimes that took as much as a half or even three quarters of an hour. And that was in a major metropolitan area, not out in the countryside. This was an unusual situation, but it did happen and not just once, but often two or more times in a week. What I could not understand was why the local power station, which was in the same general area, did not take more effective measures. I also do not understand why it took so long to slowly come back up to normal.

I choose to use the numbers 115/230 V as a way of more easily saying "whatever the local line Voltage presently happens to be, somewhere between 110/220 V and 125/250 V" which is rather lengthy. But if you really want to be completely precise, then please feel free to go over my post and substitute that language for every place where I simply said 115/230 V. Personally, I think my post was long enough already.

You say the rest of my post is also incorrect. In what way? You do not say. I have had some struggles with understanding the fine points of deriving three phases from what is called single phase and I have read a lot about it as well as giving it a lot of thought. I would appreciate a clarification. And don't worry, I won't be embarrassed.

Paul, the first incorrect assumption you made is that electric service in the USA is 115/230V. Wrong. If you want 115V (I cannot imagine why you would) you would need a buck transformer. 125/250V is pretty much standard from generating stations in most metropolitan USA locations. By the time it gets to your house or shop, losses could have taken away as much as 10% giving you 112.5/225V but that is highly unlikely unless you live way way out in the boon-docks.

Intending no disrespect but the rest of your manifesto is equally inaccurate. I only mention this, not to embarrass you, because there are some folks out there the may believe it and that could be dangerous for them.

Thank you.