Power quality analyzers 1

[MrJam]

I’m looking for the Power quality analyzer that I can get the most out of We’ve looked at the Fluke, the Ideal, the AEMC, and the Hioki 3196 and have narrowed it down to the Hioki and the AEMC because of the flexibility of these to meters. The hioki is a great deal more then the AEMC. I’d like to know why it’s so much better. The Hioke has a neutral voltage clamp for each phase that it reads. The AEMC is incapable of giving a neutral ampacity on a single phase 240 system if any one knows of an even better PQA then these to. We have to make a purchase soon and any intelligent input on the matter would be very helpful Thank you

 

[dpc]

I'm not familiar with these particular devices but some basic issues are the number of channels that can be monitored simultaneously, frequency range (highest order harmonic that can be measured), data storage and playback capability, and input voltage range and isolation rating.

It probably comes down to what types of systems you will be dealing with and the type of troubleshooting that you do.

 

[MrJam]

That’s just it I'm not sure what type of situation I'll need the meter for I don't want to buy it for the current application and then regret that I can’t use it for anything else I want to buy a well rounded unit

I'm not familiar with the isolation rating what exactly does that refer to

 

[ScottyUK]

Have a look at the range from Voltech Instruments. Yokogawa also make power analysers which may be worth a look. Get a unit on demo if you can. These are expensive items of equipment - you have the right to try them out before you buy, and the better manufacturers will assist you in this.


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If we learn from our mistakes,
I'm getting a great education!

 

[jschwei314]

Mr. Jam,

A good question and I have the same question also, What Power Quality Meter to buy?

1st. I am cheap.

2nd. Fast data logging is what 90% I need. I need 4 voltage, 4 currents. The data time stamped and put into a spead sheet. I would like data every cycle,60hz, RMS value.

The best my HOMEMADE logger can do is 1.5 sec but I have no confidence in my readings, homemade equipment.

Is there a meter out there that can do this for me.

 

[dpc]

The voltage isolation relates to the maximum voltage you can apply to the inputs without causing damage or safety problems.

If you're only connecting to 120V voltage transformer secondaries, this isn't a big concern, but we often do direct 480V or 600V connections and these can see transients exceeding 1500V or probably higher.

 

[sksimonsen]

Mr. Jam

We purchased a PowerSight 3000 Meter several years ago from Summit Technology (

http://www.summittechnology.com).

I beleive it offers everything you are looking for, and I thought at a reasonable price. They now have a 4000 model that has even more capabilities. Check them out.

 

[Skogsgurra]

I use anything from a LeCroy scope or a Yokogawa recorder or a LabView DacqCard with a logging VI up to a Dranetz/BMI PowerPlatform 4300.

The LeCroy is extremely good at transients. It has a very flexible trigger with lots of specialised functions. But it has no battery back-up and cannot record what is happening when power returns after a black-out. Also, it has only four channels. It has date and time of day. It can save to hard disk on trigger and communicate over internet.

The Yokogawa (I use a small OR 300) has 12 bit resolution and gives me very accurate recordings. It is fast enough for normal "power transients". It has very good harmonic analysis. The triggering is complete with window out/in, mask triggering (using either an ideal wave or an acquired one as mask). Four channels plus eight logic chanels. AND/OR triggering using results from several channels and lots of other functionality. It has an internal battery that is good for a couple of hours recording during an outage. It can save to PC card on trigger, or fax via an analog modem. It has date and time of day. It is light and very portable.

LabView is VERY FLEXIBLE, but you need some time to set it up and test the functions you have implemented. It can be quite fast and being graphically programmable, you can make it do just about anything you want. Usually eight channels. But more are available. Ties up a computer.

The Dranetz/BMI PP4300 is a dedicated power analyzer. It has four isolated voltage channels and four isolated current channels. It does voltage levels, harmonics, transients, frequency, phase difference, flicker and still some measurements. It can take lots of overvoltage without being damaged and it has a battery for black-out recordings. Data are saved to a PC card (the formatting of which takes a long time - it is called "building data base"). The PP4300 is a typical "disturbance recorder" and is not good if you want to record other things like looking at an automation variable like a changing speed or a valve operation. The PP4300 is also the more expensive of these instruments.

Sometimes, you really need a "recognised" instrument. If you connect an instrument that you know will do the job. And even if you get better results with the LeCroy than with the PP4300 - you will still have a discussion with those people that "are used to" the PP4300. That's why I have many different instruments.

I also use a FLUKE 41, which is a single phase analyzer. Voltage and current. Handheld. Rather old now, but very useful for a quick look.

There are also some PicoTechnology data acquisitions units on my shelves. I use them for long-term measurements where only a few channels are needed. Can be left for months and save data to disk when something happens. The do tie up a computer, though.

To conclude. There are many possible ways of doing a power quality analysis. I would look for these features:

1 Can it withstand the voltage levels? European 690 V grids can be a problem.

2 Does it have enough channels? A PE-N channel is very good to have. That means at least four (not three) voltage channels. There shall also be at least three current channels - with calibrated current clamps.

3 Does it have battery operation. If it hasn't, you will not be able to see what happens when power returns after an outage.

4 Does it have the triggering possibilities needed? You should have at least voltage level (hi and lo), transients (settable to at least twice the nominal voltage level). There are many other trigger functions that may be useful, like harmonics level, current cunsumption, var consumption and so on. The more you have the better.

5 Can it save the results? A printer is good, but often a problem generator. Better to save to disk, PC card or USB stick. An internet connection can be good, but I do not trust it - nor the fax connection. Too many factors out of your control.

6 Is it accepted by your customer? This is an important point. If you do a measurement and if it is questioned by the utility company or the machine manufacturer, then using a calibrated and universally regognised instrument makes things a lot easier.

7 Can you afford it? If not - wait until you can. Or hire an instrument. In my opinion, owning is much better than hiring. It allows you to "make friends" with the instrument and become a real expert - not just a "Messknecht" (a German expression meaning "measurement infantry man" - or "measurement GI")

8 Do you feel happy with the instrument? Life is so much easier if you do.

Gunnar Englund

http://www.gke.org

 

[itsmoked]

Very nice synopsis skogs thanks.

 

[NorthSlope]

It depends on what is most imprtant to you in a "power quality" analyzer. I have used both an rpm (now made by Fluke)and an AstroMed. If you want primarilly voltage triggered transients use the rpm. (It has 5 current channels and 4 voltage channels in "Y" configuration),and an AstroMed Dash 18 if you want cycle by cycle recording and are happy to do your own analysis of Megabytes of data.

The rpm does all the normal kW, kVA, kVAR, p.f. calculations and plots them over time. Its' triggering is not selectable or adjustable by the end-user and is voltage change based - not current change. On the other hand, the AstroMed is a great, multi-channel (up to 18) recorder with no "intelligence". It will record to disk any input you can convert to a voltage, millivolts to 800 V pk-pk. at a selectable digitization rate. Great for raw data but you can spend weeks in analysis - depending on what you recorded and what you're looking for.

 

[bacon4life]

I just went to a presentation on the PowerMonic by

http://www.gridsense.net.

It is more of a power quality monitor with the analysis part taking place once you download the data to a computer, but it may be worth a look.

 

[cflatters]

I have seen and used the square D power logic range on several jobs (PM650+ > now PM810). They are excellent instruments and measure all mannor of power quality parameters but do not do real-time waveform capture.

If you need a more powerful option look at the Power Logic CM4000 power quality meter. I have just specified a unit for a project where I am expecting to experience high levels of harmonics and regen power from container cranes.

I am sure there are some other similiar spec units (ABB ?)

 

[MissMe]

Hello, MrJam!
If you need a good Power quality analyzer I would highly recommend LEM Topas 1000 (

http://www.lem.com).

It can be used as data logger, distrubance recorder, logs transients... all at the same time.
Has a hard disk of 1 GB and can be accessed over the LAN.
It easy to set up and has a powerful software.
Maybe the price is too high, but it's worth it.
MissMe

 

[alehman]

I recently purcahsed an Amprobe DM-III. It is fairly inexpensive ($3000+-) and seems to do a good job with the basics - 3ph. volts, amps, power, VARs, pf, demands and energy usage. It also does harmonic analysis and waveform captures. It is very simple to use and amprobe has several CT options. It's not suitable for analyzing high speed transients.