Posted by Jim Wilkins on July 12, 2008, 6:14 pm
> ...
> Where do you come up with 120 VDC? I have not heard of anyone using that
> for a long time. I read a book about wind power many years ago and they
> said most AC appliances would run from 120 VDC. That may have been somewhat
> true in the 70s or 80s but I would have some doubts about trying it with
> modern appliances.
120VDC is available from engine-powered welding generators and many of
the associated power tools like grinders with universal brush motors
will run on it.
Posted by phil-news-nospam on July 12, 2008, 9:30 pm
| Where do you come up with 120 VDC? I have not heard of anyone using that
| for a long time. I read a book about wind power many years ago and they
| said most AC appliances would run from 120 VDC. That may have been somewhat
| true in the 70s or 80s but I would have some doubts about trying it with
| modern appliances.
I've heard of people using it in small amounts to power 120V lights. I just
didn't know how extensive this was.
--
|WARNING: Due to extreme spam, googlegroups.com is blocked. Due to ignorance |
| by the abuse department, bellsouth.net is blocked. If you post to |
| Usenet from these places, find another Usenet provider ASAP. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |
Posted by Bruce in alaska on July 13, 2008, 4:28 pm
wrote:
>
> | Where do you come up with 120 VDC? I have not heard of anyone using that
> | for a long time. I read a book about wind power many years ago and they
> | said most AC appliances would run from 120 VDC. That may have been somewhat
> | true in the 70s or 80s but I would have some doubts about trying it with
> | modern appliances.
>
> I've heard of people using it in small amounts to power 120V lights. I just
> didn't know how extensive this was.
Anyone who generates their own power will tell you, that Compact
Floresents are the way to go. cheap and Watts/Lumen is the best.
--
Bruce in alaska
add <path> after <fast> to reply
Posted by Ron Rosenfeld on July 12, 2008, 1:11 pm
On 11 Jul 2008 21:49:43 GMT, phil-news-nospam@ipal.net wrote:
>For those of you who run at least some DC directly to loads (bypassing any
>inverters you might have for AC), especially those who are entirely off-grid,
>what is the typical or most common voltage used?
>12V? 12/24V 24V? 24/48V? 48V? 120V? 120/240V? 240V? Variable?
>I've found switchmode power supplies for computers for 12VDC and 48VDC.
>But not a lot of other things exist for DC, except the basics like
>incandescent lighting (most of that appears to be for 12VDC). I have
>not seen anything for 120VDC in particular, including inverters (even
>though this might seem to be the just right voltage for incandescent
>lights in North America). The highest DC side voltage I've seen for
>inverters (other than the big ones designed to let solar/wind farms
>power the grid in three phases) is 48V.
I don't use an DC appliances or have DC wiring. If I required something
like that, I'd probably use 48V since that's the voltage of my battery
bank.
Inverters for grid-tied home PV systems (without battery backup) will
accept higher DC voltages.
There are a fair number of DC appliances out there. I've seen them in both
12V and 48V sizes. In addition to lighting (of various types, not just
incandescent), there are refrigerators, TV, freezer, coolers, hair dryers,
curling irons and other consumer appliances. Just do a Google search for
"DC Appliances".
When I was designing our home, I looked at DC, but given inverter
efficiency and economics, I opted for a straight AC system. DC would be
handy as a fall-back if the inverters are down. But it would be hard to
justify the expense, vs running a backup generator.
--ron
Posted by Martin Riddle on July 12, 2008, 6:02 pm
| For those of you who run at least some DC directly to loads (bypassing any
| inverters you might have for AC), especially those who are entirely off-grid,
| what is the typical or most common voltage used?
|
| 12V? 12/24V 24V? 24/48V? 48V? 120V? 120/240V? 240V? Variable?
|
| I've found switchmode power supplies for computers for 12VDC and 48VDC.
| But not a lot of other things exist for DC, except the basics like
| incandescent lighting (most of that appears to be for 12VDC). I have
| not seen anything for 120VDC in particular, including inverters (even
| though this might seem to be the just right voltage for incandescent
| lights in North America). The highest DC side voltage I've seen for
| inverters (other than the big ones designed to let solar/wind farms
| power the grid in three phases) is 48V.
|
| --
Switches and plugs are available for 12 & 24VDC. At higher voltages they get
expensive
but breakers are available for for DC systems below 60VDC, such as the Square D
QO series.
If I had to run a dc buss it would be 12 or 24v, with a properly sized fuse and
wire (125%)
If I had a 48Vdc battery bank then a DC-DC converter would be installed, but
then that gets pricey too.
Cheers
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> Where do you come up with 120 VDC? I have not heard of anyone using that
> for a long time. I read a book about wind power many years ago and they
> said most AC appliances would run from 120 VDC. That may have been somewhat
> true in the 70s or 80s but I would have some doubts about trying it with
> modern appliances.