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Discussion Starter · #1 ·
I mostly work residential in a gentrifying city -meaning lots of old panels & meters, loose bugs, crappy grounding. I get a lot of situations where 1 leg of the service entrance isn't working/intermittent arcing.

I'm looking for recommendations to get a *voltage logger* to see if problems are in the service or past the panel in the house. I'd love something as simple as clamps that I could attach before or after the meter, or in the panel at the main breaker or to a DP breaker that I instal. I could leave it there for a day or two and see what kind of info I get.

For example:
Recently I got called for "flickering lights all over the house". I look at the relatively new panel, an old meter socket and decide to check the bugs on the aerial service. Sure enough, I find under-sized bugs and pock-marks on the POCO's wires and the SE cable that feeds the house so I redo all 3 bugs.

While I'm getting my check, the kitchen lights flicker -but it doesn't look like arcing, it looks like cycling. I check the dimmers and sure enough, it's a incandescent dimmer on a bank of LEDs (I should mention that I am the 3rd electrician they've called and at least one other guy checked the dimmers, so that's just friggin' sad).

My customer calls that night: changing the dimmer helped, but it's still flickering. They also say that the receptacles in the living room (different circuit) went out for about 30 seconds and their projector reset itself.

Now I'm back to thinking it's a service leg ...so it's the meter or the meter socket...or the POCO.

This is where I'd like to have a diagnostic tool so that I don't have to climb up and disconnect the nice new job I did on the bugs just so I can safely examine/clean the meter socket. Frankly, I don't have the time to redo the service any time soon so this is a pain in ma butt :(

Anybody got suggestions for an inexpensive logger? Maybe something else?
 

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Discussion Starter · #7 ·
Ah, this makes sense. Thank you.

If i'm not mistaken, the "Beasts" are only good while you're there...so if the issue where connection problems when it's windy out, it would be useless when it's not windy. Or if water was getting in the SE, you'd have to test during the rain.
(Side note: speaking of rain... to anyone who doesn't tape up the sheathing gap at the weatherhead: seriously, how lazy can you get?)

Or am I missing something?

The point of the logger is that I get to leave it there to detect for intermittent problems *over time*. In this case, the problem cycles; I didn't time it, but I'd have to sit there staring at the Beast instead of doing something else. And if I get a log that shows intermittent anomalies on "Tuesday from 1am-6am" (while I'm hopefully sleeping) and then check the weather to see that it was windy or raining at that time...

...And as much as I like making out, I no longer use a helper :(
 

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Discussion Starter · #8 ·
Opinions? I don't know this company (Extech).

http://www.extech.com/resources/DL160data.pdf

256,000 logs @ 1 second/log over 24 hrs is about 3 days. ...and spending $300+ seems reasonable.

Any other ideas on brands or models? They have one for $50 less, but it isn't dual input and it only saves 100,000 readings (about 26 hours). Dual input seems smart since I could test a meter and a panel at the same time if they were close enough.

Thanks in advance.
 

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Chief Flunky
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I’ve had mixed results with Extech. Most of their stuff is a cut above Fluke in terms of bells and whistles but some of the converters are slow w and she me have board issues. That being said my go to Megger is an Extech and recently Flir bought them so hopefully improvements are on the way.

Look at Dranetz for top end. EIS makes the Shark series meters/switches which are the cheapest around for what they can do. Installed several. Also for power quality SEL makes one of their meters in a suitcase for this purpose.



Sent from my iPhone using Tapatalk
 

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Leaving a power quality analyzer at a house will only tell you that you have a problem, which you already know or suspect or you wouldn't be there in the first place. It also requires one or several re-visits to set it up in various locations to ferret out the source. I'd rather find it and fix it on the first visit with a beast and get it all knocked out and done right then. A power quality analyzer on a house seems like using something fancy for the sake of using somethig fancy and doesn't really translate to solving problems in my mind.
 

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Hackenschmidt
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Fixing it on the first visit would be great but there are problems you're not going to be able to reproduce while you're watching, even with the Beast.

I think a power quality monitor would be great to have and have looked at the Flukes but I have not pulled the trigger due to the much higher price tag.

That Extech looks like you get a lot for $300 but would it be enough? I am not sure if the sample rate of one second is fast enough, it might miss some things. Three days recording seems like enough. It would be nice to have at least three current probes. It would be nice to measure voltage AND current at the same time.

Extech isn't a brand I have high confidence in. I think for this kind of product you really can't be second guessing the readings you collect.

I guess what it boils down to is, I feel like if I am going to do this for customers and charge them for it, it has to be done with the right tool for the job, not the closest I could come under $500.

I could see going through quite a bit of rigmarole to record data and analyze it, and not find anything. I'd be wondering if the right tool for the job might have caught the problem, and wouldn't really feel right charging the customer for that.

Then again if I DID figure it out with the $300 Extech data I'd feel GREAT that I didn't spend the extra $7,000.00 for the Fluke!

I guess you have to ask which way your luck runs :)
 

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I'm scratching my head trying to figure out exactly what resi problems a recording meter will find and help you solve.
 

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Hackenschmidt
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I'm scratching my head trying to figure out exactly what resi problems a recording meter will find and help you solve.
I will give you one!

I have a customer whose office building is over 100 years old. It's about house sized, real nice old building, beautifully renovated about 20 years ago. They were apparently having surges and power outages overnight, even in clear weather, and their neighbors had no trouble.

They are on a separate transformer but have a neighbor that's a run down old industrial service, but I don't have any specifics there.

I ran in circles with their problems until one day a train went by in the back. I didn't even know there were tracks back there, but they are REAL close. I am not sure if the lights dimmed or I was seeing stars, my teeth were rattling. Turns out the building was an old railroad office :)

Anyway the problems were usually occurring at night because train traffic is mostly at night there. They never thought to mention the trains, they had never noticed anything happen during business hours when the train went by.

I checked things on the premises, and the electrician that did the work when they built the place came out (out of retirement!) and found nothing serious. I cajoled the power company and they came out and of course claim they found no trouble, but they were working in the neighborhood half a day or so (unfortunately I was not there while they were working). The problems haven't recurred, it's been a couple years now.

I suspect the neutral was opening due to vibration at the transformer and the power monitor would have seen occasional changes in the line-neutral voltage at the panel, and you would be able to corroborate that was coming from an open neutral by calculating the change in voltage and comparing it in the load on each leg at that moment.
 

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I suspect very much you could have duplicated that marginal neutral with a heavy load from a beast even if the trains weren't going by.
 
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Can't Remember
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I'd like to have a PQ/energy monitor too, but my biggest problem is knowing how to interpret what I'm seeing. I have been looking at them for possible monitoring to better help size larger generators for commercial jobs. I'd like to see peak KW for instance, but unsure on how much data it'll acquire vs the sample time etc. I'd have to experiment some before I felt confident enough to say by looking at the data. I think looking at it, I might be able to say here's the problem on the screen, but you'd still be left with, where is it physically?
 

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Hackenschmidt
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I suspect very much you could have duplicated that marginal neutral with a heavy load from a beast even if the trains weren't going by.
I don't know, I kind of doubt it, there are lots of line - neutral loads, coffee makers, space heaters under the desks, etc. Heavy vibration causes problems that aren't there at all under normal conditions.

There are always going to be problems that are intermittent, that you won't be able to produce on demand, for those, monitoring is often the best you can do.
 

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I'd like to have a PQ/energy monitor too, but my biggest problem is knowing how to interpret what I'm seeing. I have been looking at them for possible monitoring to better help size larger generators for commercial jobs. I'd like to see peak KW for instance, but unsure on how much data it'll acquire vs the sample time etc. I'd have to experiment some before I felt confident enough to say by looking at the data. I think looking at it, I might be able to say here's the problem on the screen, but you'd still be left with, where is it physically?
Generator work would be an excellent use for a recording instrument. Although I just get a couple year's worth of billing data from the power company to do that. A lot of them can give you pretty detailed 15 minute demand data also depending on the metering arrangement.

The "where is it physically" problem remains with all sorts of testing. Some of it is gut feeling and experience, but sometimes you're down to moving the meter around and collecting data for an awful lot of trips till you finally stumble upon some smoking gun. It is what it is.
 
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Hackenschmidt
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I think for demand monitoring you can use a much different type of meter. For power quality, you need the fast sample rate, and you want more channels, voltage and current - it's going to be a lot more expensive.

For demand etc., I don't think you care about a fast sample rate, and you just need to monitor current on the legs. This Extech would do two weeks on single phase residential service at five second sample rate if my math is right.
 

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Discussion Starter · #20 ·
The train example is a good one; we have trolleys here and that has been an issue. Another good one is people running up and down stairs.

The amperage test conditions with The Beast seems like a good idea for anomalies happening very frequently or on a regular cycle, but it also seems like it's more hit or miss ...plus you have to stare at it. And the 20 amp version doesn't seem like much of a "triggering" load unless this is happening so often that the problem could be solved with a space heater and a VOM. That doesn't seem like it's worth $700+. ...but the 80 amp version is $2,000+; so no way. This kind of mystery is a problem I see WAY less than once a year; the vast majority of the time, it's very obvious what the problem is.

So I still like the idea of a logger. Starting at the panel feeds, I can divide and conquer (service cable/meter or panel/circuit) and also find out if there are specific circumstances like time and weather. I mean, i'm going to open the panel anyway and one thing that works for *me* in terms of multiple visits is that I only work within 20 minutes of my house. So moving the logger is going to be something I do on my way out in the morning or my way home -less than a 10 minute visit including pleasantries unless I need to get on my ladder.

*Another* nice thing about the loggers is that most of them have alarms you can set, so if the voltage drops while you are doing other work in the house, you'll know without having to stare at the thing. So I'd just move it while I'm there.

It occurs to me that a voltage drop alarm could be a handy way of testing the neutral when upgrading the grounding/bonding system (I do a lot of that for POCO service re-introductions and home buyer's inspection reports). A little better than having to walk back to the panel to check a VOM.
 
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