Batteries
in [Mandrake]
|
From: Adam on 7 Oct 2007 20:37 Peter D. wrote: >> Yesterday morning I measured about 42.5W total household power >> consumption with the printer unplugged, and about 28.5W with it plugged >> in but switched off, using method #3 on >> http://michaelbluejay.com/electricity/measure.html . Something isn't >> right there. (Everything was switched off except for the clocks and the >> things that have a "standby" state, like the VCR and the touch-on lamp.) > > Maybe.. > > Something you don't know about is switching on/off in response to a > thermostat (the fridge?) or a timer (the VCR?). Thanks, Peter, but I already thought of that. The fridge was switched off during those measurements, and the VCR wasn't scheduled to record anything until at least the following day. > You have a highly reactive load and a cheap power meter. It is > plausible that your power meter is actually an Amp meter, so > plugging in a device that corrects the power factor will reduce > your electricity costs. Now that's certainly possible. This is the power meter that the local electric company installed, apparently quite a few years ago. (Others in the same "bank" for other apartments in my building are the digital kind.) Does this mean that if I got more of this same model printer, my electric bill would go down? :-) > You are going crazy. I don't see how that would interfere with my ability to measure power consumption. :-) Adam
From: Adam on 7 Oct 2007 23:19 Moe Trin wrote: >> Yesterday morning I measured about 42.5W total household power >> consumption with the printer unplugged, and about 28.5W with it plugged >> in but switched off > > You're trying to measure a single appliance by measuring the entire > house - which is subject to some pretty significant errors - "Peter D." > mentions power factor which is a pretty good point. I vaguely remember "power factor." I suppose a fan would be a mostly inductive load. >>> If you can't borrow an AC ammeter, yeah, I'd ignore it. If it's just >>> the fan, you're probable talking about 15 Watts or less. Let's see... my latest electric bill (the big one covering July and August) comes to about $0.1413 per kW-hr. 15W means about $18.57/year. And I did a quick Google search, and apparently some larger laser printers do have an always-on fan. I wasn't sure if mine was defective that way. When the system unit's fans and HDs are running, the amount of noise it adds isn't very significant. >> Would it be okay to plug it into my surge protector-power strip, which >> has a UL rating of 15A? > > that would probably be OK - further assumption is that the rest of the > load on the power strip doesn't exceed the 15A limit. I'd have to add the numbers up, since the printer's rated 10A just by itself. > [compton ~]$ ls -l ether/ethernet-becker* | cut -c30- > 6929 Jul 13 2001 ether/ethernet-becker-7.13.01 > 4805 Sep 7 2001 ether/ethernet-becker-9.07.01 > 5054 Sep 28 2002 ether/ethernet-becker-9.29.02 > [compton ~]$ grep eepro100.h ether/ethernet-becker* | cut -c1-30,65- > ether/ethernet-becker-7.13.01: 19541 Jun 29 2000 eepro100.html > ether/ethernet-becker-9.07.01: 19541 Jun 29 2000 eepro100.html > ether/ethernet-becker-9.29.02: 12197 Mar 29 2002 eepro100.html > [compton ~]$ > > I _think_ that's what you are looking for. Still looking for it. What exactly does it show? >> [root(a)ozymandias ~]# /usr/sbin/tcpdump -i eth10 -n >> 17:06:50.258539 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request >>from 00:60:b0:38:69:6c, length: 548 > > Yeah, nobody home. How did you get it working before? It works with a parallel-port connection. Hasn't yet ever worked with 10BaseT connection. >> I'm deliberately using a surge protector that includes phone line >> protection, on the assumption (not necessarily correct) that they share >> a common ground. > > I'd also like to see them commoned up at the building entry point, so > that all fault currents aren't going through the surge protector. I'll look outside and see if I can find anything like that. [APC Smart-UPS 1500, battery missing] >> Yesterday I plugged a load into it (150W incandescent bulb) then >> plugged it into a working outlet, but neither the LEDs nor the lamp >> lit up despite trying both buttons on the UPS. > > No LEDs says either a fuse is blown on the input, or the battery is so > flat that it's sucking the charging circuit dry. > > Assuming it's not a fuse, leave it plugged in for 24 hours - does > that show anything on the battery LEDs to the left? Is that worth trying when it has no battery at all? > you should be getting an > annual water quality report from the water supplier - it's an EPA > requirement. I don't recall getting one, but then I'm not the owner. Adam
From: Peter D. on 8 Oct 2007 02:13 on Monday 08 October 2007 10:37 in the Usenet newsgroup alt.os.linux.mandrake Adam wrote: > Peter D. wrote: >>> Yesterday morning I measured about 42.5W total household power >>> consumption with the printer unplugged, and about 28.5W with it plugged >>> in but switched off, using method #3 on >>> http://michaelbluejay.com/electricity/measure.html . Something isn't >>> right there. (Everything was switched off except for the clocks and the >>> things that have a "standby" state, like the VCR and the touch-on >>> lamp.) >> >> Maybe.. >> >> Something you don't know about is switching on/off in response to a >> thermostat (the fridge?) or a timer (the VCR?). > > Thanks, Peter, but I already thought of that. The fridge was switched > off during those measurements, and the VCR wasn't scheduled to record > anything until at least the following day. There are lots of strange little devices in a modern home. VCRs have a dew protection system in them, rather than risk the damage that dew can cause they will quietly turn on a small heater when needed. Do you have any battery backed devices that recharge when they think it is a good idea? Shaver, clock, UPS, burgler alarm, smoke detector, mobile phone, bilge pump, electric blanket, etc. >> You have a highly reactive load and a cheap power meter. It is >> plausible that your power meter is actually an Amp meter, so >> plugging in a device that corrects the power factor will reduce >> your electricity costs. > > Now that's certainly possible. This is the power meter that the local > electric company installed, apparently quite a few years ago. (Others > in the same "bank" for other apartments in my building are the digital > kind.) Does this mean that if I got more of this same model printer, my > electric bill would go down? :-) In general no. Briefly... When AC power is applied to a purely resistive load the voltage and current are perfectly in phase with each other (pf=1) everything works at its most efficient and you bill is minimised for the power that you use. When the load is purely inductive or capacitive the voltage and current are 90 degrees out of phase with each other. (pf=0) True power used is zero. A cheap current meter pretending to be a power meter will cause your electricity utility to bill you for the "imaginary power" you used, and yes that is the correct term for it. Inbetween loads get inbetween results. It is usually not worth the effort in an ordinary home, but adding an extra capacitor or inductor to balance out the existing reactive load so that the whole thing appears to be resistive can minimise your bill in special circumstances. Remember that you would have to re-tune the device every time you turned anything on or off. >> You are going crazy. > > I don't see how that would interfere with my ability to measure power > consumption. :-) Are you sure? -- sig goes here... Peter D.
From: Robert M. Riches Jr. on 8 Oct 2007 16:55 On 2007-10-08, Peter D. <psd(a)live.home.invalid> wrote: > on Monday 08 October 2007 10:37 > in the Usenet newsgroup alt.os.linux.mandrake > Adam wrote: > >> Peter D. wrote: >>>> .. > >>> You have a highly reactive load and a cheap power meter. It is >>> plausible that your power meter is actually an Amp meter, so >>> plugging in a device that corrects the power factor will reduce >>> your electricity costs. >> >> Now that's certainly possible. This is the power meter that the local >> electric company installed, apparently quite a few years ago. (Others >> in the same "bank" for other apartments in my building are the digital >> kind.) Does this mean that if I got more of this same model printer, my >> electric bill would go down? :-) > > In general no. > > Briefly... > > When AC power is applied to a purely resistive load > the voltage and current are perfectly in phase with each other (pf=1) > everything works at its most efficient and you bill is minimised for > the power that you use. > > When the load is purely inductive or > capacitive the voltage and current are 90 degrees out of phase with > each other. (pf=0) True power used is zero. A cheap current > meter pretending to be a power meter will cause your electricity > utility to bill you for the "imaginary power" you used, and yes > that is the correct term for it. > > Inbetween loads get inbetween results. It is usually not worth > the effort in an ordinary home, but adding an extra capacitor or > inductor to balance out the existing reactive load so that the > whole thing appears to be resistive can minimise your bill in > special circumstances. Remember that you would have to re-tune > the device every time you turned anything on or off. If Adam is in the US, at least in theory the meter installed by the electric utility is _supposed_ to properly measure real power and disregard reactive (imaginary) power. If I remember correctly, it was Professor Chaston who said in an EE power course that the law allows utilities to bill only for real power and not for reactive (imaginary) power. -- Robert Riches spamtrap42(a)verizon.net (Yes, that is one of my email addresses.)
From: Moe Trin on 8 Oct 2007 20:42
On Mon, 08 Oct 2007, in the Usenet newsgroup alt.os.linux.mandrake, in article <vlhOi.651$yJ2.55(a)trndny01>, Adam wrote: >Moe Trin wrote: >> "Peter D." mentions power factor which is a pretty good point. > >I vaguely remember "power factor." I suppose a fan would be a mostly >inductive load. The small AC fans are almost always a synchronous motor, which would be a capacitive load, depending on how heavy the mechanical load on the motor. One factory I remember had lots of 3 phase AC motors running large tools (lots of inductive load), and had some fans run by large synchronous motors (light mechanical load = lots of capacitive reactance), to a) help move the air around (this was before widespread use of air conditioners), and b) try to add some leading power factor. >Let's see... my latest electric bill (the big one covering July and >August) comes to about $0.1413 per kW-hr. I don't have the sheets handy, but mine is FAR more complicated as there is a daily charge, one rate for "on peak" (M-F 09:00-21:00), another for "off peak" (other times), a rate based on the highest one hour of peak use, and a bunch of fees (total 12%) on the sum of all of the rates. >15W means about $18.57/year. Ah, the simple life. > And I did a quick Google search, and apparently some larger laser >printers do have an always-on fan. I wasn't sure if mine was defective >that way. When the system unit's fans and HDs are running, the amount >of noise it adds isn't very significant. Most printers are meant to be near people, so they do tend to try to keep the running noise down. I do recall some printers that if you were going to be close for a while, ear protection was advisable. >>> Would it be okay to plug it into my surge protector-power strip, >>> which has a UL rating of 15A? >> >> that would probably be OK - further assumption is that the rest of >> the load on the power strip doesn't exceed the 15A limit. > >I'd have to add the numbers up, since the printer's rated 10A just by >itself. Think also what is on that circuit. My house is modern (1990), and the outlets in each room get a 20 Amp circuit (except for the kitchen which has three), while the overhead lights and fans are on two additional 15 Amp circuits for the whole house. I actually added an extra circuit for the 'computer room' so it now has two 20 Amp circuits. >Still looking for it. What exactly does it show? [compton ~]$ head ether/eepro100.txt Scyld Linux and the Intel PCI EtherExpress Pro 100 series Products Supported This page contains information on using Linux with the Intel PCI EtherExpress Pro 100 series, the Pro/100B, Pro/100+, and other PCI boards using the i82557, i82558 or i82559 chips. [compton ~]$ >> Yeah, nobody home. How did you get it working before? > >It works with a parallel-port connection. Hasn't yet ever worked >with 10BaseT connection. In one of your earlier posts, you had the card in the computer with a 192.0.0.192 address. How did that come up? >> I'd also like to see them commoned up at the building entry point, so >> that all fault currents aren't going through the surge protector. > >I'll look outside and see if I can find anything like that. I'd expect it next to the electric meters >> Assuming it's not a fuse, leave it plugged in for 24 hours - does >> that show anything on the battery LEDs to the left? > >Is that worth trying when it has no battery at all? Not really - the battery is also part of the line filter, and if it's missing, the system may not be very reliable. They claim you can hot swap the batteries, but we never try. When it's time for a battery replacement, we normally swap the unit out - accepting the short power outage. >> you should be getting an annual water quality report from the water >> supplier - it's an EPA requirement. > >I don't recall getting one, but then I'm not the owner. Who gets the water bill? It normally is included annually in one of the bills. Old guy |