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Posted on 04/22/2009 4:04:11 PM PDT by posterchild
At work they shuttle people from building to building in one of these.
So far I've managed to avoid it.
Minor techie note... nominal house line voltage is 117VAC. Depending on where you live, anything between about 112 and 122 is considered "within normal range", and people say "110", "115", or "120" interchangeably.
Below 110VAC some appliances start getting unhappy, especially single-phase motors. Above 125VAC things like incandescent light bulbs shorten lifetime like crazy.
Out here in the boonies of upstate NY, we see anything from 105VAC to 130VAC at times.
Not me personally, mind you -- I'm on a sun-powered (photovoltaic) system, off-grid (way up on a hill), and my 24VDC-input inverter puts out 117VAC right on the nose, all day and night. NYSEG can KMA.
Suuure. I bet you’re already thinking of ordering one like the Peapod/Tatermobile above...snicker!
Are you the guy who announces the arrival of the plane? :)
That nominal has been climbing for decades. When I was getting my EE degree it was more like 112, and most everyone used "110". When I got my MSEE, only 4 years later, it was closer to 115. One of the two winters when I was in Grad school, the phase lag got to record levels, as coal fired generators had to be taken off line because the coal piles were frozen, and because barges couldn't get up the rivers with more coal. I think it was winter of '75 - '76, but I'm not sure, but I recall that winter as being dang cold in the center of the country. It was well below zero, with wind gusts to 40 mph the day I and my brother in law registered, and my brother went through drop/add as an undergrad.
That 120+/- 0.1 has been remarkably constant at work every since I got the UPS, about 3 years ago. I figure that is pretty good, since otherwise the system is pretty unreliable, going down, sometimes for hours, at the least hint of lighting induced surge. (That might be a bit harsh, but only a bit.
Looks like it has better seats than the Messiahmobile.
That's been my observation as well. I suspect it may be (at least in part) to try to compensate for copper in ever-longer last-mile connections. And perhaps, on the assumption that more and more devices are powered with "universal" 110-240VAC switching power inputs, the higher line voltage (and correspondingly lower line current) are an economic win due to lower I^2R losses.
If you're seeing 120+/-0.1 at the input to your UPS, I would suspect your local dropdown transformer is within spitting distance. Or if you work at a big plant, they have their own local regulation.
In 1979 I was working at Borg-Warner Electronics designing 50-400HP 3-phase inverters for var-speed induction motor control, and we had to have our own local 3-phase for engineering testing -- otherwise when the 400HP units would fault, we risked taking out the entire building with the surge. Heh, power is fun... ;-)
I wouldn't know. The only "power" outfits I interviewed with didn't offer me a job. So I went the way of the dark side, into defense electronics. First love anyway, and I've drifted, more like raced, away from the hardware side of things, into systems design and analysis. Radar signal processing, terrain following aircraft control design, radar missile seeker simulation, and so forth.
Then I devolved to training simulations, but still using my radar and tracking background, and it wasn't all simulation anyway, the system could also use live data and allow the students to control live aircraft, but still using my tracking filters designed for the simulation. Also did an aircraft simulation for a formation situational awareness trainer, implemented on a desktop PC.
The last 3 1/2 years, I've paid the price for all that fun, and am doing software configuration management, documentation *review*, and acting as a gadfly tech adviser.
I wouldn't know. The only "power" outfits I interviewed with didn't offer me a job. So I went the way of the dark side, into defense electronics. First love anyway, and I've drifted, more like raced, away from the hardware side of things, into systems design and analysis. Radar signal processing, terrain following aircraft control design, radar missile seeker simulation, and so forth.
Then I devolved to training simulations, but still using my radar and tracking background, and it wasn't all simulation anyway, the system could also use live data and allow the students to control live aircraft, but still using my tracking filters designed for the simulation. Also did an aircraft simulation for a formation situational awareness trainer, implemented on a desktop PC.
The last 3 1/2 years, I've paid the price for all that fun, and am doing software configuration management, documentation *review*, and acting as a gadfly tech adviser.
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