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Power quality monitor -- cheap?
I'm looking for the most economical means to monitor mains voltage for spikes
and other such disturbances over an unattended period of time. I see that there are 2 categories of monitoring and logging equipment: event loggers and samplers. The former requires the setting of thresholds and will record any event that exceeds these; the latter simply samples the input at a set interval. I am looking for a device that records events. I'd rather avoid the very expensive power quality monitors ($2000-plus category). This reduces the list to DMMs with logging capability, which includes the Fluke 189. (I'll add that if a data-download option exists, I would prefer the ability to review data on the device rather than *require* that it be downloaded -- I want to be able to, at a glance, confirm that a power problem exists, and have the *option* to download the data for detailed examination if I wish.) Any other suggestions to achieve my means would be greatly appreciated. Thanks, -- John English |
Power quality monitor -- cheap?
On a sunny day (Wed, 21 Feb 2007 12:13:59 -0800) it happened John E.
wrote in .net: I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. A simple idea: Divide the main to .7V eff with 2 resistors. Feed into PC soundcard line input. Record a wave file at 8000 samples/second mono. Bit harddisk space should last a long time. When done enter recorded wave file in an audio editor, display waveform, and look for peaks, etc.... |
Power quality monitor -- cheap?
Please! I hope you mean to have this buffered through an isolation
transformer! Jan Panteltje wrote: On a sunny day (Wed, 21 Feb 2007 12:13:59 -0800) it happened John E. wrote in s.net: I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. A simple idea: Divide the main to .7V eff with 2 resistors. Feed into PC soundcard line input. Record a wave file at 8000 samples/second mono. Bit harddisk space should last a long time. When done enter recorded wave file in an audio editor, display waveform, and look for peaks, etc.... -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P |
Power quality monitor -- cheap?
Otherwise its a good idea except for the safety issue. Get a step down
transformer from "mains" to 6 or 12 volts so that you dont fry anything. Jan Panteltje wrote: On a sunny day (Wed, 21 Feb 2007 12:13:59 -0800) it happened John E. wrote in s.net: I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. A simple idea: Divide the main to .7V eff with 2 resistors. Feed into PC soundcard line input. Record a wave file at 8000 samples/second mono. Bit harddisk space should last a long time. When done enter recorded wave file in an audio editor, display waveform, and look for peaks, etc.... -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P |
Power quality monitor -- cheap?
"Jan Panteltje" wrote in message ... I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. A simple idea: Divide the main to .7V eff with 2 resistors. NO! At least run the AC through a 120 - 12 volt step-down transformer first. Hooking AC directly to the input of a computer is a seriously bad idea. -- .. -- .. .. .. .. .. .. .. .. -- |
Power quality monitor -- cheap?
"John E." wrote in message
news.net... I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. I see that there are 2 categories of monitoring and logging equipment: event loggers and samplers. The former requires the setting of thresholds and will record any event that exceeds these; the latter simply samples the input at a set interval. I am looking for a device that records events. I'd rather avoid the very expensive power quality monitors ($2000-plus category). This reduces the list to DMMs with logging capability, which includes the Fluke 189. (I'll add that if a data-download option exists, I would prefer the ability to review data on the device rather than *require* that it be downloaded -- I want to be able to, at a glance, confirm that a power problem exists, and have the *option* to download the data for detailed examination if I wish.) Any other suggestions to achieve my means would be greatly appreciated. Thanks, -- John English I don't know of an inexpensive commercial solution for catching fast transients and harmonic distortion. The Fluke 189 will capture sags and surges if you set the log rate fast enough, and it will capture 250uS transients, although I don't recall how much it can do simultaneously. I have one, but I don't use it for that purpose. It stores 100 readings, and does have a com port for uploading data. You might also consider a BMI 4800, generally available on eBay pretty cheap. It has a built-in printer which will print actual waveforms, and also had a communication option. It is old technology, and not the smallest physical package, but it does a good job on transients, and the price is right. The other professional equipment that I use is definitely outside of your stated budget. You might start finding the Fluke 43 at a more reasonable price on eBay, since there are newer instruments now on the market. If you can get one, it works well for single-phase monitoring. It stores and displays locally, and can upload to a PC for further analysis. The other option is to roll your own, as others have suggested. However, I will also emphasise isolation if you are connecting your PC to the power line! Ben Miller -- Benjamin D. Miller, PE B. MILLER ENGINEERING www.bmillerengineering.com |
Power quality monitor -- cheap?
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Power quality monitor -- cheap?
Ideal Industries has an interesting low cost product called the Voltage
Performance Monitor. You cannot download data from it or see waveforms, but it does count events outside of the ITIC curve (update of the old CBEMA curve) and categorizes them based on type and severity. It is reasonably accurate in doing this characterization, not something that can be said of all meters, even more expensive ones. Charles Perry P.E. Not an indorsement. I don't have a financial interest, etc, insert legal weasel words, whatever. "John E." wrote in message news.net... I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. I see that there are 2 categories of monitoring and logging equipment: event loggers and samplers. The former requires the setting of thresholds and will record any event that exceeds these; the latter simply samples the input at a set interval. I am looking for a device that records events. I'd rather avoid the very expensive power quality monitors ($2000-plus category). This reduces the list to DMMs with logging capability, which includes the Fluke 189. (I'll add that if a data-download option exists, I would prefer the ability to review data on the device rather than *require* that it be downloaded -- I want to be able to, at a glance, confirm that a power problem exists, and have the *option* to download the data for detailed examination if I wish.) Any other suggestions to achieve my means would be greatly appreciated. Thanks, -- John English |
Power quality monitor -- cheap?
John E. wrote:
I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. I'm not positive of this, but I believe some of the UPS systems that have cabled monitoring, i.e. hook to your computer via serial port or USB, will give a power line reading if queried. Don't ask me which ones. I know my TrippLite 1000VA unit has a front-panel display and I *suspect* it would tell the computer the line voltage if asked. -- "Nowadays, security guys break the Mac every single day. Every single day, they come out with a total exploit, your machine can be taken over totally. I dare anybody to do that once a month on the Windows machine." -- Bill Gates, in an interview with Newsweek's Steven Levy |
Power quality monitor -- cheap?
John E. wrote:
I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. I see that there are 2 categories of monitoring and logging equipment: event loggers and samplers. The former requires the setting of thresholds and will record any event that exceeds these; the latter simply samples the input at a set interval. I am looking for a device that records events. I'd rather avoid the very expensive power quality monitors ($2000-plus category). This reduces the list to DMMs with logging capability, which includes the Fluke 189. (I'll add that if a data-download option exists, I would prefer the ability to review data on the device rather than *require* that it be downloaded -- I want to be able to, at a glance, confirm that a power problem exists, and have the *option* to download the data for detailed examination if I wish.) Any other suggestions to achieve my means would be greatly appreciated. Thanks, How about one of these? https://www.doubleed.com/secure.html |
Power quality monitor -- cheap?
"**THE-RFI-EMI-GUY**" wrote in message ... Please! I hope you mean to have this buffered through an isolation transformer! Why should he? It's the equivalent of use a "scope" probe to look at line voltage. The "danger" is at the probe tip but not at the end going to the scope. There is a question of just how well a transformer will pass the transients. OTOH, without compensation it's possible that the "voltage divider" may not properly pass the transients. That's why scope probes were so expensive. I do grant that a transformer makes it so that if you make a mistake (like forget to connect the "lower" resistor) you don't have a shock risk. I have never done this. I note that "they" now sell the equivalent of the input side of a sound card that's as big as one's thumb and plugs into the USB port. Personally, I would like to be able to monitor start up current and voltage transients when my "heavy stuff" (heat pump and deep well water pump) starts up. |
Power quality monitor -- cheap?
"John E." wrote in message news.net... I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. I see that there are 2 categories of monitoring and logging equipment: event loggers and samplers. The former requires the setting of thresholds and will record any event that exceeds these; the latter simply samples the input at a set interval. I am looking for a device that records events. I'd rather avoid the very expensive power quality monitors ($2000-plus category). This reduces the list to DMMs with logging capability, which includes the Fluke 189. (I'll add that if a data-download option exists, I would prefer the ability to review data on the device rather than *require* that it be downloaded -- I want to be able to, at a glance, confirm that a power problem exists, and have the *option* to download the data for detailed examination if I wish.) Fluke VR101S JB |
Power quality monitor -- cheap?
John E. wrote:
I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. A cheap UPS? Mine can be queryed via a serial port and tells you line voltage and frequency (along with a lot of other things you probably don't care about). Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 Fax ONLY: 972-2-648-1443 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
Power quality monitor -- cheap?
On Wed, 21 Feb 2007 21:14:45 -0600, clifto wrote:
John E. wrote: I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. I'm not positive of this, but I believe some of the UPS systems that have cabled monitoring, i.e. hook to your computer via serial port or USB, will give a power line reading if queried. Don't ask me which ones. I know my TrippLite 1000VA unit has a front-panel display and I *suspect* it would tell the computer the line voltage if asked. Now that you mention it, my PowerWare UPS does have this feature, and a program can record line conditions based on a polling interval. Probably nto the best solution however since I am sure short (single cycle) faults will be lost in this setup. Another alternative is eBay. I see products like the Amprobe monitors (older, chart type) selling for about $100 or so. Hell, I'll sell mine for that! bg |
Power quality monitor -- cheap?
On Wed, 21 Feb 2007 12:13:59 -0800, John E. wrote:
I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. I see that there are 2 categories of monitoring and logging equipment: event loggers and samplers. The former requires the setting of thresholds and will record any event that exceeds these; the latter simply samples the input at a set interval. I am looking for a device that records events. I'd rather avoid the very expensive power quality monitors ($2000-plus category). This reduces the list to DMMs with logging capability, which includes the Fluke 189. (I'll add that if a data-download option exists, I would prefer the ability to review data on the device rather than *require* that it be downloaded -- I want to be able to, at a glance, confirm that a power problem exists, and have the *option* to download the data for detailed examination if I wish.) Any other suggestions to achieve my means would be greatly appreciated. Call the power company and see if they'll lend you one. Good Luck! Rich |
Power quality monitor -- cheap?
PeterD wrote:
On Wed, 21 Feb 2007 21:14:45 -0600, clifto wrote: John E. wrote: I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. I'm not positive of this, but I believe some of the UPS systems that have cabled monitoring, i.e. hook to your computer via serial port or USB, will give a power line reading if queried. Don't ask me which ones. I know my TrippLite 1000VA unit has a front-panel display and I *suspect* it would tell the computer the line voltage if asked. Now that you mention it, my PowerWare UPS does have this feature, and a program can record line conditions based on a polling interval. Probably nto the best solution however since I am sure short (single cycle) faults will be lost in this setup. Right. It's only really good for trends. But sometimes faults follow trends. And it's a whole lot less data to process than, say, 600 Hz samples of line voltage over a week (362,880,000 samples to check). -- "Nowadays, security guys break the Mac every single day. Every single day, they come out with a total exploit, your machine can be taken over totally. I dare anybody to do that once a month on the Windows machine." -- Bill Gates, in an interview with Newsweek's Steven Levy |
Power quality monitor -- cheap?
"John Gilmer" wrote in message ... Why should he? It's the equivalent of use a "scope" probe to look at line voltage. The "danger" is at the probe tip but not at the end going to the scope. No, it isn't. The designer of the scope will have at least contemplated what happens when you are examining a live circuit at 120 or 240 volts. Will the designer of the computer have done as much? -- .. -- .. .. .. .. .. .. .. .. -- |
Power quality monitor -- cheap?
Right! which reminds me some time back, I gave Helga some bad advice
involving live electricity and a swimming pool. She hasn't posted since! ;-P Homer J Simpson wrote: "John Gilmer" wrote in message ... Why should he? It's the equivalent of use a "scope" probe to look at line voltage. The "danger" is at the probe tip but not at the end going to the scope. No, it isn't. The designer of the scope will have at least contemplated what happens when you are examining a live circuit at 120 or 240 volts. Will the designer of the computer have done as much? -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P |
Power quality monitor -- cheap?
On Feb 23, 12:38 am, **THE-RFI-EMI-GUY**
wrote: Right! which reminds me some time back, I gave Helga some bad advice involving live electricity and a swimming pool. She hasn't posted since! ;-P Homer J Simpson wrote: "John Gilmer" wrote in message ... Why should he? It's the equivalent of use a "scope" probe to look at line voltage. The "danger" is at the probe tip but not at the end going to the scope. No, it isn't. The designer of the scope will have at least contemplated what happens when you are examining a live circuit at 120 or 240 volts. Will the designer of the computer have done as much? -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P I am still shaking my head, nobody mentioned a GFI. Isolation transformer is an oxymoron. I can show anybody how an Isolation transformer won't provide any isolation what so ever. When that 4800volt line that is over head of the 220 Mains, drops on the 220 lines, that so called isolation transformer is toast. It happened to my neighbor. Power company said it was an act of god. Until the neighbor came up with the defective splice, (that wasn't crimped) they used on the 4800volt line. I would use a high speed opto coupler with 6000 volt isolation. 73 N8ZU |
Power quality monitor -- cheap?
On a sunny day (Thu, 22 Feb 2007 01:54:17 -0500) it happened "John Gilmer"
wrote in : "**THE-RFI-EMI-GUY**" wrote in message .. . Please! I hope you mean to have this buffered through an isolation transformer! Why should he? It's the equivalent of use a "scope" probe to look at line voltage. The "danger" is at the probe tip but not at the end going to the scope. There is a little catch here. The PC case is normally connected to mains ground, and we want the quality of the line between zero and phase, then without a transformer we also grab all the noise and stuff between ground and zero. That could show some peaks in some cases.. R1 | ---------------------- live --------===------------------------| soundcard line in | | [ ] R2 | |____________| soundcard ground --------------------- zero------------ not | connected | | | PC case --------------------- ground (safety) -------------------------|_____________ |
Power quality monitor -- cheap?
"ray13" wrote in message
oups.com... I am still shaking my head, nobody mentioned a GFI. Isolation transformer is an oxymoron. I can show anybody how an Isolation transformer won't provide any isolation what so ever. When that 4800volt line that is over head of the 220 Mains, drops on the 220 lines, that so called isolation transformer is toast. It happened to my neighbor. Power company said it was an act of god. Until the neighbor came up with the defective splice, (that wasn't crimped) they used on the 4800volt line. That doesn't mean an isolation transformer "won't provide any isolation what so ever". Just that it has a voltage breakdown limit, like every other transformer and electrical device that connects to the power system. I don't know what kind of transformer your neighbor used, but there are some available with breakdown at least equal to the optoisolator that you proposed. WIth regard to this thread, an isolation transformer serves a very significant purpose. Without it, an open neutral connection to the sensing resistors or an open resistor, would put the entire computer at line potential with respect to the earth. This could damage the mother board or something connected to it, or cause an electrocution. An isolation transformer will prevent this from happening by isolating the line voltage from the computer. If you disconnect the neutral from the transformer primary, there will be no voltage on the computer. Ben Miller -- Benjamin D. Miller, PE B. MILLER ENGINEERING www.bmillerengineering.com |
Power quality monitor -- cheap?
There is a little catch here. The PC case is normally connected to mains ground, and we want the quality of the line between zero and phase, then without a transformer we also grab all the noise and stuff between ground and zero. That could show some peaks in some cases.. True. If your sound card can record stereo, you can make channel 1, "Neutral" and channel 2, "Hot." |
Power quality monitor -- cheap?
On a sunny day (Fri, 23 Feb 2007 21:41:59 -0500) it happened "John Gilmer"
wrote in : There is a little catch here. The PC case is normally connected to mains ground, and we want the quality of the line between zero and phase, then without a transformer we also grab all the noise and stuff between ground and zero. That could show some peaks in some cases.. True. If your sound card can record stereo, you can make channel 1, "Neutral" and channel 2, "Hot." Exactly, do a differential. So then split the tracks, and substract with my substract wave program (Linux): http://panteltje.com/panteltje/dvd/s...t_wave-0.3.tgz reload the result in a good sound editor, do a FFT.. what not. One could even listen to it ;-) |
Power quality monitor -- cheap?
If a 4800 or 7200 V overhead crossed with the secondary lines to ANY
home, I would expect there would be plenty of damage to go around. In fact, I doubt a typical opto isolator is big enough (lead distance) to prevent arc over in the worst case. ray13 wrote: On Feb 23, 12:38 am, **THE-RFI-EMI-GUY** wrote: Right! which reminds me some time back, I gave Helga some bad advice involving live electricity and a swimming pool. She hasn't posted since! ;-P Homer J Simpson wrote: "John Gilmer" wrote in message ... Why should he? It's the equivalent of use a "scope" probe to look at line voltage. The "danger" is at the probe tip but not at the end going to the scope. No, it isn't. The designer of the scope will have at least contemplated what happens when you are examining a live circuit at 120 or 240 volts. Will the designer of the computer have done as much? -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P I am still shaking my head, nobody mentioned a GFI. Isolation transformer is an oxymoron. I can show anybody how an Isolation transformer won't provide any isolation what so ever. When that 4800volt line that is over head of the 220 Mains, drops on the 220 lines, that so called isolation transformer is toast. It happened to my neighbor. Power company said it was an act of god. Until the neighbor came up with the defective splice, (that wasn't crimped) they used on the 4800volt line. I would use a high speed opto coupler with 6000 volt isolation. 73 N8ZU -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P |
Power quality monitor -- cheap?
John E. wrote:
I'm looking for the most economical means to monitor mains voltage for spikes and other such disturbances over an unattended period of time. I see that there are 2 categories of monitoring and logging equipment: event loggers and samplers. The former requires the setting of thresholds and will record any event that exceeds these; the latter simply samples the input at a set interval. I am looking for a device that records events. I'd rather avoid the very expensive power quality monitors ($2000-plus category). This reduces the list to DMMs with logging capability, which includes the Fluke 189. (I'll add that if a data-download option exists, I would prefer the ability to review data on the device rather than *require* that it be downloaded -- I want to be able to, at a glance, confirm that a power problem exists, and have the *option* to download the data for detailed examination if I wish.) Any other suggestions to achieve my means would be greatly appreciated. Thanks, So rent one. -- JosephKK Gegen dummheit kampfen die Gotter Selbst, vergebens.Â*Â* --Schiller |
Power quality monitor -- cheap?
"John E." wrote in message news.net... I'd rather avoid the very expensive power quality monitors ($2000-plus category). Rent one. |
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