1 |
Hamish Marson wrote: |
2 |
> Dale wrote: |
3 |
> >> Mike Williams wrote: |
4 |
> >>> On Thursday 03 August 2006 19:27, James wrote: |
5 |
> >>> |
6 |
> >>>> The simplist solution is NOBODY puts a 240 VAC power supply |
7 |
> >>>> into a computer unless it's going to draw some serious current |
8 |
> >>>> (amps) thus by the nature of it being 240 VAC, you already know |
9 |
> >>>> it is a power hog. |
10 |
> >>>> |
11 |
> >>> Now, I'm not electrical engineer, but I know my way around a fuse |
12 |
> >>> board and electricity having fitted out both our new offices for |
13 |
> >>> power, network, and some walls. |
14 |
> >>> |
15 |
> >>> In the UK, and most (if not all) of Europe, Africa, and Asia too, |
16 |
> >>> run on about 240 volts, 230 +-10% I think now. Pretty much the |
17 |
> >>> whole world, except the Americas. |
18 |
> >>> |
19 |
> >>> |
20 |
> >> Well, the USA has the same coming in too. We have 220v to 240v |
21 |
> >> coming in but that is split into different legs for the 110v to |
22 |
> >> 120v stuff. |
23 |
> >> |
24 |
> |
25 |
> Unless those two legs are in phase, you're still only getting |
26 |
> 110V-120V AC. IIRC (And it's from 20 years ago I'm working here) it's |
27 |
> not, it's just two legs of the 3 phase generated power. Which means |
28 |
> they're 120 deg out of phase, and so you still only get 110-120V. In |
29 |
> order to get 220-240V, you'd need 3 phase power. |
30 |
> |
31 |
> I suspect you get two 110V lines because of current limitations. Not |
32 |
> to provide you with 220V which you'r enot going to get from just |
33 |
> adding two out of phase lines. (Unless of course the US has wired up |
34 |
> two in-phase separate 110V lines. In which case you can get 220V outof |
35 |
> it, but I seem to remember a lecture in Eng Sci saying it was common |
36 |
> to take 2 of 3 phases to a house in the US & alternate which 2 between |
37 |
> successive houses. |
38 |
|
39 |
The two lines are out of phase. Here, big things like air conditioners, |
40 |
stoves, dryers and central heat run off the 220 or 240v wires. Small |
41 |
things like lights, hair dryers, fans and even small window air |
42 |
conditioners run off the 110 or 120v lines. In most places here, 3 |
43 |
phase is not available unless you are in a area that has large factories |
44 |
or are in a city. Here the black and white wires are 120v, the red and |
45 |
black wires are 220 or 240v. Also note, you can tell the power company |
46 |
which one you want when you get them to put up your pole. We had 220v |
47 |
for years. When the transformer went out I asked for 240V. With a |
48 |
light load we actually get about 248v or so. When something like the |
49 |
A/C turns on it will drop to about 240v or so. It stays pretty stable |
50 |
after that though. Keep in mind that light bulbs blow faster at the |
51 |
higher voltage. At the same time A/C compressors run a lot more efficient. |
52 |
> |
53 |
> >> If you are using transformers to reduce it from 220v to 110v, that |
54 |
> >> will waste some energy right there. Transformers are not real |
55 |
> >> efficient. If you touch it and it is warm, that is what you are |
56 |
> >> wasting. That will also make whatever you are cooling with work |
57 |
> >> harder too. |
58 |
> >> |
59 |
> |
60 |
> Plus you need twice the current at 110V vs 220V. (Volts are big 'V' |
61 |
> BTW! Named after Voltaire). This means higher line losses as loss is |
62 |
> proportional to current. Higher line losses mean that cable length |
63 |
> becomes more of a problem. (A 10V drop in 240V is less than 5%. 10V |
64 |
> drop in 120V is almost 10%. Much more significant). |
65 |
> |
66 |
> All-in-all I prefer 240V single phase. |
67 |
> |
68 |
> H |
69 |
|
70 |
As far as being efficient with power usage, me two. I have a friend |
71 |
that uses some heavy equipment and some of them are 480v. They put out |
72 |
a lot more horsepower but they run very cool because the current draw is |
73 |
so small. |
74 |
|
75 |
We here would likely be better off if we did use 220v like other |
76 |
countries but it would take us years to convert things over. |
77 |
|
78 |
Dale |
79 |
:-) |
80 |
-- |
81 |
gentoo-user@g.o mailing list |