Power, etc.
in [Mandrake]
|
Prev: House Wiring
Next: Ethernet Printer Connection
From: Adam on 14 Oct 2007 19:52 Robert M. Riches Jr. wrote: [separate power and phone grounding rods] >> Should I try to inconspicuously connect the two outdoor ground posts >> with 12-gauge wire? :-) > > You'd want heavier wire than that. I think it was around > 1992 I was told in US new residential construction that if > there were separate ground rods, they had to be bonded > together with #4 wire (about 5/16" diameter). You'd want > that bonding wire to carry a whole lot of current with very > small voltage drop. Thanks, Robert. I don't think I could make #4 wire inconspicuous, though. :-) More details a few paragraphs down. Moe Trin wrote: >> The manual for the laser printer says minimum recommended circuit >> capacity is 16A at 120V. > > The disadvantage of using a "commercial" style printer on a home > setup. ;-) I couldn't resist a bargain -- a working (dinosaur of a) color laser printer and several years' worth of toner, for free. > As long as the _actual_ load on the circuit remains > below 15 Amps, you're OK though I'd be concerned about adding stuff > accidentally onto the same circuit. I found out exactly which outlets are on that circuit. At present, power strip for entire computer system (tower case with unknown power supply rating, 17" CRT monitor, inkjet printer, scanner, small speakers, faxmodem, DSL router), 5 lamps (one 150W, others under 100W), three digital clocks, fan, paper shredder, humidifier in season (essentially small fan), answering machine, and of course the laser printer. Circuit breaker's never blown yet. > What kind of distance between the two? By the way, this is only a > concern if you get a strike that hits the ground (or tries to use a > ground rod) within a hundred feet or so. I didn't measure it, but I'd guess about twenty feet between the power grounding rods and the telco's grounding rod. >> Should I try to inconspicuously connect the two outdoor ground posts >> with 12-gauge wire? :-) > > Would you believe a number 4 or larger? A hundred feet of 12 AWG is > 0.159 Ohms - 4 AWG is 0.025 Ohms. My trusty CRC Handbook of Chemistry and Physics, 1951-1952 Edition, reports the same numbers (p.2791). For standard annealed copper wire at 20C (68F), resistance per 1000 feet is 0.2485 ohms for 4 AWG, 1.568 for 12 AWG, 0.09827 for 0 AWG, 0.04901 for 0000 AWG (diameter 0.46"!), 4.016 for 16 AWG, 6.385 for 18 AWG, and 25.67 for 24 AWG. When I worked retail 20 years ago, it was hard to avoid saying something whenever anyone bought the 24 AWG speaker wire. [APC Smart-UPS 1500 w/o battery] > What I've > done is to use a motorhome battery (high current, deep discharge) > bought from the auto-parts store. I had to kludge up the connection > (the battery I used has standard automotive style posts) but was able > to bug lugs and appropriate wire (short run of 6 AWG) so that the > battery is now external (in a nylon box). That sounds workable, but given my system it sounds like overkill. > Remember what you want the UPS for. It's to provide the energy needed > to allow the system to do an orderly shutdown - ideally after a few > minutes to weather "short" outages. Next time you shut the system > down, time how long it takes from initiating the shutdown until the > system either shuts down, or reports "System Halted". Good point. The idea isn't to keep the system usable, but to let it shut down properly, or (more likely in my case) keep it running through short (few seconds or less) power outages. Gotta figure out what power rating I'd need on a UPS. >> I think 1G should >> be adequate for running both Mandriva and some other OS under VMWare, >> since each OS ran well enough on its own when I had 640M. > > an x86 is probably safe for two or three years The possibly interesting story of what happened when I bought more RAM is now posted in a.o.l.mandriva. See "New RAM slowed hda access: Why?" > I really haven't been paying attention to the rental markets in years. > In NorCal - specifically the "South Bay" (roughly Hayward down to San > Jose and up to Palo Alto), housing is very tight My cousin and her husband were renting a house in Los Gatos (two over from Woz). They wanted to buy it, but just couldn't afford to. When that house became unsafe (strong winds blew the porch through the roof), they were able to find a new house to rent, and move everything into it, within six days. I still can't believe it. Adam
From: Moe Trin on 15 Oct 2007 20:27 On Sun, 14 Oct 2007, in the Usenet newsgroup alt.os.linux.mandrake, in article <sZxQi.2319$Oy1.2029(a)trndny08>, Adam wrote: >> The disadvantage of using a "commercial" style printer on a home >> setup. ;-) > >I couldn't resist a bargain -- a working (dinosaur of a) color laser >printer and several years' worth of toner, for free. Well, the toner is certainly worth it >> As long as the _actual_ load on the circuit remains below 15 Amps, >> you're OK though I'd be concerned about adding stuff accidentally >> onto the same circuit. > >I found out exactly which outlets are on that circuit. At present, >power strip for entire computer system (tower case with unknown power >supply rating, 17" CRT monitor, inkjet printer, scanner, small speakers, >faxmodem, DSL router), That's probably OK - the computer power supply might be rated at 350 to 500 Watts, but they're generally not loaded that badly. The monitor is probably around 100VA. >5 lamps (one 150W, others under 100W), three digital clocks, fan, >paper shredder, humidifier in season (essentially small fan), answering > machine, and of course the laser printer. Circuit breaker's never >blown yet. Yeah, miracles sometimes happen. I certainly wouldn't turn on all the lamps when you want to use that printer. >When I worked retail 20 years ago, it was hard to avoid saying >something whenever anyone bought the 24 AWG speaker wire. Or the 15 Amp extension cords of #16 SJT (or the even lighter ones made with molded plastic connectors). >> Remember what you want the UPS for. It's to provide the energy needed >> to allow the system to do an orderly shutdown - ideally after a few >> minutes to weather "short" outages. Next time you shut the system >> down, time how long it takes from initiating the shutdown until the >> system either shuts down, or reports "System Halted". > >Good point. The idea isn't to keep the system usable, but to let it >shut down properly, or (more likely in my case) keep it running through >short (few seconds or less) power outages. Gotta figure out what power >rating I'd need on a UPS. APC has a guide on their website. Something able to carry the CPU and monitor for 6 or 7 minutes when new is enough. >The possibly interesting story of what happened when I bought more RAM >is now posted in a.o.l.mandriva. See "New RAM slowed hda access: Why?" That one is absolutely bizarre. You say it took 20 minutes to boot. Were you watching it do so? Where did it hang? No obvious errors in the log, what about errors to the screen? Disk activity? No, I don't have any ideas beyond memtest. >My cousin and her husband were renting a house in Los Gatos (two over >from Woz). They wanted to buy it, but just couldn't afford to. When >that house became unsafe (strong winds blew the porch through the roof), >they were able to find a new house to rent, and move everything into it, >within six days. I still can't believe it. Obviously that's a big "that depends" based on the date, and what they were willing to pay. When we moved into our last rental in 1981, it took about 3 weeks to jump through the hoops. Los Gatos is a bedroom community, and is a bit of a commute from most places. There are two freeways (17 and 85) and you can get to two expressways (Lawrence and San Tomas) but none were an easy drive. The commute up to Moffett (85/237/101) tends to run 40 to 60 minutes, and it's only about 16 miles. Even the drive to "1 Infinite Loop" (gotta love that address - my favorite bookstore was in the same campus at 3 Infinite Loop) which is just off 280 in Cupertino) isn't much better though I doubt Woz ever did that during commute hours. The last house we rented (~1982) was costing $1250/month. We asked the real estate agent we were using to find a home what the house we were in would cost. Her answer? 475k (a block off San Antonio near Middlefield - a 3/2 with flat roof and no insulation built in 1955) just into Mountain View. Took us a bit, but we found a place in the next town South (Sunnyvale) for a mere 155k (3/1 built in 1950). Old guy
From: Adam on 17 Oct 2007 22:44 Moe Trin wrote: >> I found out exactly which outlets are on that [15A] circuit. At present, >> power strip for entire computer system (tower case with unknown power >> supply rating, 17" CRT monitor, inkjet printer, scanner, small speakers, >> faxmodem, DSL router), > > That's probably OK - the computer power supply might be rated at 350 to > 500 Watts, but they're generally not loaded that badly. The monitor is > probably around 100VA. Sticker on back of monitor says "2.0A". >> 5 lamps (one 150W, others under 100W), three digital clocks, fan, >> paper shredder, humidifier in season (essentially small fan), answering >> machine, and of course the laser printer. Circuit breaker's never >> blown yet. > > Yeah, miracles sometimes happen. I certainly wouldn't turn on all the > lamps when you want to use that printer. Only two of the lamps ever spend any significant amount of time on, the ones at the computer and the nighttable. And I'm gradually replacing most of those with screw-in fluorescents anyway. I'm sure the circuit breaker will tell me if I ever have too many of those things on at once. >> When I worked retail 20 years ago, it was hard to avoid saying >> something whenever anyone bought the 24 AWG speaker wire. > > Or the 15 Amp extension cords of #16 SJT (or the even lighter ones > made with molded plastic connectors). From _The Complete Book of Pitfalls: A Victim's Guide to Repairs, Maintenance, and Repairing the Maintenance_, under "Housebuilding Don'ts": Item -- A man wired his entire house with thin lamp cord. The local electrician won't even drive by the house, for fear somebody will remember his truck when the house burns down. > APC has a guide on their website. Something able to carry the CPU and > monitor for 6 or 7 minutes when new is enough. Thanks for the link. Let's see... 350-500W for the CPU and 240W (?) for the monitor... APC recommends their 750VA model. But I just bought RAM and my car insurance is due... one of these days... before winter storms start would be a good idea. >> The possibly interesting story of what happened when I bought more RAM >> is now posted in a.o.l.mandriva. See "New RAM slowed hda access: Why?" > > That one is absolutely bizarre. You say it took 20 minutes to boot. > Were you watching it do so? Where did it hang? No obvious errors in > the log, what about errors to the screen? Disk activity? No, I don't > have any ideas beyond memtest. See post in a.o.l.mandriva with subject "New RAM slowed hda access: Why? SOLVED - CORRECTION." It was the setting for Video RAM that did it. My only guess is there. I was watching it boot, on and off. It didn't hang, just took a VERY long time for each step of the process, and with anything I did after login. No errors seen on screen or in any log. > Even the drive to "1 Infinite Loop" (gotta > love that address - my favorite bookstore was in the same campus at > 3 Infinite Loop) which is just off 280 in Cupertino) My cousin, the one in Los Gatos, showed me the buildings on Infinite Loop. She grew up in Cupertino, but can't even show me where the house used to be because the land isn't even there any more -- it was ALL removed to make way for a freeway that is on ground about 30 feet lower than the house was on. She also showed me the shacks of Cupertino, complete with tarps used to repair the roofs and junked cars in the front yard. Yes, in Cupertino. And I'll put in a plug for her business, which is a product that lets you do a complete frame-off car restoration in a space no bigger than one shop bay or an ordinary home's garage: http://www.frameoff.com/ . Adam
From: Unruh on 18 Oct 2007 14:31 Adam <look(a)bottom.for.address> writes: >Moe Trin wrote: >>> I found out exactly which outlets are on that [15A] circuit. At present, >>> power strip for entire computer system (tower case with unknown power >>> supply rating, 17" CRT monitor, inkjet printer, scanner, small speakers, >>> faxmodem, DSL router), >> >> That's probably OK - the computer power supply might be rated at 350 to >> 500 Watts, but they're generally not loaded that badly. The monitor is >> probably around 100VA. >Sticker on back of monitor says "2.0A". That is 220W. >>> 5 lamps (one 150W, others under 100W), three digital clocks, fan, >>> paper shredder, humidifier in season (essentially small fan), answering >>> machine, and of course the laser printer. Circuit breaker's never >>> blown yet. >> >> Yeah, miracles sometimes happen. I certainly wouldn't turn on all the >> lamps when you want to use that printer. >Only two of the lamps ever spend any significant amount of time on, the >ones at the computer and the nighttable. And I'm gradually replacing >most of those with screw-in fluorescents anyway. I'm sure the circuit >breaker will tell me if I ever have too many of those things on at once. >>> When I worked retail 20 years ago, it was hard to avoid saying >>> something whenever anyone bought the 24 AWG speaker wire. >> >> Or the 15 Amp extension cords of #16 SJT (or the even lighter ones >> made with molded plastic connectors). > From _The Complete Book of Pitfalls: A Victim's Guide to Repairs, >Maintenance, and Repairing the Maintenance_, under "Housebuilding Don'ts": >Item -- A man wired his entire house with thin lamp cord. The local >electrician won't even drive by the house, for fear somebody will >remember his truck when the house burns down. >> APC has a guide on their website. Something able to carry the CPU and >> monitor for 6 or 7 minutes when new is enough. >Thanks for the link. Let's see... 350-500W for the CPU and 240W (?) for >the monitor... APC recommends their 750VA model. But I just bought RAM >and my car insurance is due... one of these days... before winter storms >start would be a good idea. >>> The possibly interesting story of what happened when I bought more RAM >>> is now posted in a.o.l.mandriva. See "New RAM slowed hda access: Why?" >> >> That one is absolutely bizarre. You say it took 20 minutes to boot. >> Were you watching it do so? Where did it hang? No obvious errors in >> the log, what about errors to the screen? Disk activity? No, I don't >> have any ideas beyond memtest. >See post in a.o.l.mandriva with subject "New RAM slowed hda access: Why? >SOLVED - CORRECTION." It was the setting for Video RAM that did it. My >only guess is there. I was watching it boot, on and off. It didn't >hang, just took a VERY long time for each step of the process, and with >anything I did after login. No errors seen on screen or in any log. >> Even the drive to "1 Infinite Loop" (gotta >> love that address - my favorite bookstore was in the same campus at >> 3 Infinite Loop) which is just off 280 in Cupertino) >My cousin, the one in Los Gatos, showed me the buildings on Infinite >Loop. She grew up in Cupertino, but can't even show me where the house >used to be because the land isn't even there any more -- it was ALL >removed to make way for a freeway that is on ground about 30 feet lower >than the house was on. She also showed me the shacks of Cupertino, >complete with tarps used to repair the roofs and junked cars in the >front yard. Yes, in Cupertino. And I'll put in a plug for her >business, which is a product that lets you do a complete frame-off car >restoration in a space no bigger than one shop bay or an ordinary home's >garage: http://www.frameoff.com/ . >Adam
From: Moe Trin on 18 Oct 2007 20:29
On Thu, 18 Oct 2007, in the Usenet newsgroup alt.os.linux.mandrake, in article <iMzRi.5671$W22.4818(a)trndny04>, Adam wrote: Moe Trin wrote: >The monitor is probably around 100VA. > >Sticker on back of monitor says "2.0A". 240 - 250 VA is a bit more than I'd expect. Got a make/model/FCC-ID? >> I certainly wouldn't turn on all the lamps when you want to use >> that printer. > >Only two of the lamps ever spend any significant amount of time on, the >ones at the computer and the nighttable. And I'm gradually replacing >most of those with screw-in fluorescents anyway. I'm sure the circuit >breaker will tell me if I ever have too many of those things on at once. No doubt - but I'd hate to be doing something on the computer (open files) when that happens. > From _The Complete Book of Pitfalls: A Victim's Guide to Repairs, >Maintenance, and Repairing the Maintenance_, under "Housebuilding >Don'ts": > >Item -- A man wired his entire house with thin lamp cord. The local >electrician won't even drive by the house, for fear somebody will >remember his truck when the house burns down. Long ago in a land far away (Vung Tau, .vn, ~1967) I'm visiting a co-worker at his home on Back Beach, and noted that as soon as we arrived, he turned on the (fluorescent) lamps (standard dual 40 Watt tubes). If he waited till it started to get dark, there wouldn't have been enough voltage to start them. Next time I went out there, I paid a bit closer attention to the utility lines. The last ~1/4 mile were lamp cord. Asked about this, he reported that it was an improvement over the 'Field Telephone Wire' (nominally 16AWG, but 7 strands, 4 of copper, 3 of steel) used on the next "street". >Thanks for the link. Let's see... 350-500W for the CPU and 240W (?) >for the monitor... APC recommends their 750VA model. But I just >bought RAM and my car insurance is due... one of these days... before >winter storms start would be a good idea. I suspect that's way over what is needed, but the only way to find out is to stick an ammeter in there and measure. The two workstations on my desk at work are running off a single 700 VA unit. Old guy |