Power Line Quality Monitor that does not cost a fortune - Page 1
Forum section: electronics / testgear

author: nealix
author_rank: Regular Contributor
timestamp: March 18, 2022, 09:27:43 pm
content: I am looking to find a residential single-phase plug-in power line quality monitor thatdoes not cost $4000 to $7500 like Fluke or other industrial stuff. Does anyone knowof any lower cost (under $600) units that can monitor/log spikes, noise, surges, sags,and other basic disturbances? We have repeated flickering of lights, and I want tobe able to show actual data before calling the power company or paying an electrician.Most of the flickering is on circuits with light dimmers (Lutron Diva), and all is with LEDlighting. Yes, I know that these two are most sensitive to power line disturbances, andI am interested in learning more about the power quality and how many "hits" per hourare happening.So far, most loggers or monitors that I find under $1500 are only logging/recordingvoltage at several samples per minute, and not spikes, harmonics, noise, etc.Any ideas?Neal

author: tautech
author_rank: Super Contributor
timestamp: March 18, 2022, 09:42:17 pm
content: Quote from: nealix on March 18, 2022, 09:27:43 pmMany LED SMPS are not dimmable and/or if not loaded correctly will flicker.You sparkie should know all about this sort of stuff.

author: coppice
author_rank: Super Contributor
timestamp: March 18, 2022, 09:46:11 pm
content: Quote from: tautech on March 18, 2022, 09:42:17 pmEven most LED lamps which are sold as dimmable have significant parts of their operating envelope where they flicker.

author: nealix
author_rank: Regular Contributor
timestamp: March 19, 2022, 12:12:31 am
content: Thanks guys, well aware of all this about LED lighting. The original post still stands as a question.Does anyone know of AC Power Quality Monitor / Logger that does not cost a fortune?Thanks,Neal

author: Gregg
author_rank: Super Contributor
timestamp: March 19, 2022, 12:15:56 am
content: Neal,I have a Powertronics D3000 monitor that may work for your purpose that I would sell cheap. I have the manual also. There are a couple of these on flea-bay if you want a picture of one. PM me if you are interested.Gregg

author: tautech
author_rank: Super Contributor
timestamp: March 19, 2022, 01:07:47 am
content: Quote from: nealix on March 19, 2022, 12:12:31 amWhattabout a $499 DSO with logging ?https://siglentna.com/application-note/datalogging-with-the-four-channel-sds1000x-e-oscilloscope-models/

author: nctnico
author_rank: Super Contributor
timestamp: March 19, 2022, 01:46:25 am
content: And how are you going to connect that DSO to mains safely? You'll need to add at least another $150 to buy a CAT rated differential probe.

author: tautech
author_rank: Super Contributor
timestamp: March 19, 2022, 02:20:55 am
content: Quote from: nctnico on March 19, 2022, 01:46:25 amWhy use a diff probe, it's not needed with a single phase mains supply with a PEN.However your comment about using a CAT rated probe is correct and a $50 100x scope probe would give sufficient protection for scope and operator especially when the OP is US based and mains is just 110VAC.

author: threephase
author_rank: Regular Contributor
timestamp: March 19, 2022, 08:52:50 am
content: Cheapest Instrument I know of is the OM-DVCV from Omega, that will give you 1 second sample rate.https://www.omega.com/en-us/data-acquisition/data-loggers/specialty-data-loggers/om-dvcv-logger/p/OM-DVCVThere are also power logging clamp meters available from a number of manufacturers that can record measurements on single phase systems. They can be cheap for basic voltage / current recording, but if you want more measurement parameters, then the price goes up.There is also the Uni-T UT283A or GW Instek GPM-8310 Power Analyser available, but they will bust your $600 budget.There are a number of threads on eevblog if you search regarding single phase power monitoring, you may find this one useful to read;https://www.eevblog.com/forum/testgear/some-questions-about-power-analyzers/Depends on how much work you want to do yourself and the exact specs you require, but ultimately an off the shelf power analysers is always going to be expensive as they are a more niche piece of test equipment, measuring higher voltages and large data collection and a $600 budget is unrealistic without compromises. At least you didn't ask for 3-phase.

author: Kean
author_rank: Unknown
timestamp: March 19, 2022, 09:00:53 am
content: One of the newer Powertronics monitors seems like a better choice than the ebay unknowns. I've never used one, but they've been in the industry for years.A single phase unit can be had for about US $450, and works on 120V or 240V circuits. Unlike many of the more expensive ones it doesn't do any current monitoring - it is specifically for monitoring and recording disturbances.https://powertronics.com/products/pqr-d50-power-line-monitorEdit to add: For your use case, the lower cost "Probe 100" model with USB may even be suitablehttps://powertronics.com/products/probe-100-plus-rs232-120v-ac-power-line-monitor

author: nealix
author_rank: Regular Contributor
timestamp: March 19, 2022, 04:55:31 pm
content: @Kean:Thanks for that note about the PQR D50 from PowerTronics. I emailed some questions to the company,and based on reply, I may test-drive one from Amazon next week. I understand that it is an olderdesign with software from the windows 2000 days, but it is certainly newer than the D3000 model.Good thing about test driving from Amazon, is that I can return it easy if the unit does not liveup to the datasheet, and also pay no shipping.@Gregg: Also thanks for the offer on the D3000.Thanks again. Both of these suggestions meet the needs and original question.Cheers,Neal

author: nealix
author_rank: Regular Contributor
timestamp: March 19, 2022, 05:51:17 pm
content: Quote from: tautech on March 19, 2022, 01:07:47 am@Tautech:Not a bad idea, and I already have one, thanks :-) BUT;In order to get what a power line quality logger does, you would need the scope todo both of these in parallel all day long:A. Each minute, log and timestamp the RMS voltage.andB. A tree of trigger events to also log anytime they occur:1. Trigger on surge (slow rise above 120 volts) and log data.2. Trigger on sag (slow dip below 120VAC and log data.3. Trigger on spike (rapid pulse like rise above 120VAC and log.4. Trigger on cycle drop outs and log data.5. Trigger on common mode noise and log event data.6. Trigger on high frequency noise and log event data.While I could sit with my scope all Saturday and manually play with all thesetypes of trigger events (some with added external circuits), that is not timeeffective for me. The Power Line Quality Monitors will sit there all weeklogging any of these types of disturbances, so I can go shopping, work,eating, playing, etc.Cheers,Neal

author: tautech
author_rank: Super Contributor
timestamp: March 19, 2022, 06:35:50 pm
content: NealI strongly suspect you can do most of that with one or more of the Logic triggers.Grab the User manual:https://siglentna.com/wp-content/uploads/dlm_uploads/2021/08/SDS1000X-ESDS1000X-U_UserManual_EN05B.pdfJust outta bed so something to check later today.

author: Kean
author_rank: Unknown
timestamp: March 20, 2022, 05:36:38 am
content: Yes, the Powertronics devices seem to have changed enclosures and form factors multiple times over the years but internally they are very likely to be based around the same tried and true design (if it ain't broke...)The software does look a bit dated, but it should still run on a modern Windows PC. And thankfully (hopefully!) it isn't like you need to use the software day-in and day-out.If you check the PQR50/52 manual that can be downloaded from their website support section you will see from about halfway through they document the serial communications command set used by their software. So even if you don't use Windows, or hit some compatibility issue, the documentation is excellent and gives you a workaround.

author: bdunham7
author_rank: Super Contributor
timestamp: March 20, 2022, 05:53:03 am
content: Just a thought before you get in too deep--what type of breaker panel do you have? If you have Zinsco/Sylvania or Federal Pacific service panel, you likely have arcing bus bars.Also, you're going to need to correlate any 'events' to the actual flickering otherwise you'll just have a lot of data that you don't know is relevant to the issue. Your LED/dimmer combo may be sensitive to certain things, but not others. I've seen flickering LED issues many times and it has never been a PQ issue, at least not an electric company power issue.

author: Alti
author_rank: Frequent Contributor
timestamp: March 20, 2022, 09:37:19 am
content: Quote from: nealix on March 18, 2022, 09:27:43 pmIn such case you do not want a power quality monitor. Even when you show them a data from the most sophisticated gear, they won't take any direct actions based on that. Instead, they temporarily install their own calibrated gear at your location to reject your claims.IMHO you just need to show them that single quality parameter out of many does not meet the contract agreement. Find out what your local regulations are (norms) and use the scope to trigger on SINGLE violation. For sure not every sag or overvoltage qualifies as violation here.This way you'll get legal power quality monitor temporarily installed (for almost free).

author: geggi1
author_rank: Frequent Contributor
timestamp: March 20, 2022, 05:18:32 pm
content: Som light dimmers have a minimum load required before flickering.Check if there is a potmeter when you pull off the control knob on the dimmer.

author: nealix
author_rank: Regular Contributor
timestamp: March 20, 2022, 10:28:56 pm
content: Quote from: bdunham7 on March 20, 2022, 05:53:03 amGood call :-) Yes, when we moved in 8 months ago the first thing we did was replace the Zinsco meter panel. I have done that after moving into my last two homes.Zinsco is well known for burning houses down. In fact, during Escrow, any half-way decent home inspector will flag a Zinsco meter panel as "needing replacement".To all the other responders, thanks. It's not just the dimmer and flickering issue. We get a fair number of cycle drops that cause my UPS to start up.We also get a fair number of sags. I suspect that somewhere within a mile of my home is some VERY aged power pole equipment that is starting to arc, corrode,or fail. The engineer side of me is curious to look at some data, and see 24 hour counts and disturbance types. After that, I can decide if I first call my electricianor my utility. (I also need to speak to my neighbors and see if it is just my home. I did already pull the covers off the meter panel, and my garage sub-panel, andtorqued down all breakers and busbar connections.)And @TauTech: Yes, I do have a 1000 series scope and do intend to unpack it from the move, and hook in a 6 volt AC step-down/isolation transformer so I caneasily and safely scope the line and see how clean or dirty the power looks. But for fun, I also ordered the PowerTronics PQR D50 mentioned above. It will behere Monday.Thanks,Neal

author: bdunham7
author_rank: Super Contributor
timestamp: March 20, 2022, 10:57:08 pm
content: Are you with SCE or LADWP? I'm a bit inland and I see a few glitches a week that trigger my multiple UPSes or dim the lights a bit, I presume they're switching events because our power poles and such are mostly in good shape. Is your transformer within sight of your house?

author: nealix
author_rank: Regular Contributor
timestamp: March 21, 2022, 04:27:34 pm
content: Quote from: bdunham7 on March 20, 2022, 10:57:08 pmMy util is S.C.E.For the transformer (Pole Pig), that was replaced 6 months ago via crane when it blew during rain. The drop lines to the meter panel were alsore-stripped and re-spliced by my request at that time. SCE has been replacing other pole pigs in the area, one by one. The area has olderinfrastructure.Switching events are of little concern to me (like a neighbors AirCon siwthcing on), since those rarely if ever bother my equipment or computer,and are so fast, they tend to not be annoying even on LED lighting.For the other events, like longer duration sag, arcing, noise, bad flourescent ballast, LED lighting at specifics points in dimming cycle, yes, all ofthose are easy to notice and very annoying.I think with the combination of a power line disturbance logger, and playing with my Rigol 1000 series scope, I should be able to learn enoughand collect enough data to better understand what combination of things is going on.Thanks,Neal

author: Gregg
author_rank: Super Contributor
timestamp: March 22, 2022, 02:48:11 am
content: Neal,A few other things worth checking:Is the wire from the drop to the meter and from the meter to the main breaker aluminum? If so, most of your problems may be bad connections behind the meter. An infrared thermal camera may find bad connection problems at the meter and breaker panel easier than other methods.Another test is to load one 115V leg of the 230V system as much as possible with things like toasters, plug in heaters etc. up to about 50 amps and check the voltage drop on that leg as well as the other 115V leg. Check on the meter side of the main breaker. If the loaded leg voltage drops significantly and the other leg voltage increases approximately the same amount, there may be a bad neutral connection at the pole pig or even too small of a transformer capacity.While a leg is loaded, also check the voltage drop across the main breaker and all other breakers in the panel.Also make sure that the neutral and ground are bonded in only one location (usually in the main breaker panel) otherwise you can have circulating neutral / ground currents that will drive you cray trying to locate. If possible, use a clamp meter on the ground wires from branch circuits to look for neutral currents returning via the ground instead of the neutral conductor.Gregg

author: tablet_monkey
author_rank: Newbie
timestamp: December 03, 2024, 06:35:32 pm
content: Compelling solution,https://hackaday.com/2024/12/02/esp32-powers-diy-smart-energy-meter/

author: 5U4GB
author_rank: Super Contributor
timestamp: December 04, 2024, 02:06:29 pm
content: Quote from: tautech on March 19, 2022, 01:07:47 amGiven that this appears to be a rather intermittent issue, wouldn't that leave you with potentially hundreds of hours worth of mostly nothing that you need to dig the glitches out of? The advantage of a dedicated device is that it'll capture the anomaly and skip all the boring bits.

author: 5U4GB
author_rank: Super Contributor
timestamp: December 04, 2024, 02:10:55 pm
content: Quote from: threephase on March 19, 2022, 08:52:50 amFor something like that an even cheaper option would be to get a Modbus power meter like the Eastron SDM-230s, those will read two dozen or more parameters and you can poll them as fast as the serial link will allow, then discard everything that's nothing-to-see-here and only report the anomalous conditions.

author: tautech
author_rank: Super Contributor
timestamp: December 04, 2024, 02:15:32 pm
content: Quote from: 5U4GB on December 04, 2024, 02:06:29 pmHerein lies the power of a DSO trigger and Search function.

author: pswired
author_rank: Newbie
timestamp: May 30, 2025, 04:47:53 pm
content: For anyone still following this thread, I'd recommend a SEL-735 for this purpose.https://selinc.com/products/735/You can pick these up on eBay used for <$1000. You can connect to this via serial or ethernet to pull event data and visualize in SEL SynchoWave software (free). Power quality triggers are very customizable. By default it will trigger on sag/swell/drop events but you can also configure harmonic/flicker/etc triggers. It's also obviously a power meter, so you can view voltage/current phasor data and even send PMU data to an external system if you feed it with an accurate clock source. It comes with some relay-based GPIO and you can define onboard logic for that IO (trigger your generator to start if PQ is bad but voltage is within acceptable limits, etc.)