# Powermate PM0126000 Power Quality



## tabora (Sep 6, 2018)

In an emergency situation in October 2017, I purchased a PowerMate PM0126000 at Home Depot (actually right out of the back of a semi-trailer) to replace my temporarily dead Generac (broken valve). I've now got it all rigged up as a home standby generator in a mini-shed with power louvers and a propane snorkel adapter making it dual fuel. One thing I was wondering about was the quality of the electricity from this non-inverter unit.

Today, in preparation for the coming storm, I ran the generator for 1/2 hour and took the opportunity to hook it up to my Dranetz Power Line Monitor/Analyzer. After 1/2 hour running it with various lights and loads, including an air compressor cycling, I was happy to discover that there were no power quality issues reported by the Dranetz. In addition, the sine waves generated by both poles of the generator were surprisingly non-stepped - looked like real A/C utility power with just some slight rippling on the falling side of the waves. I was expecting severely stepped sine approximations and was pleasantly surprised.
:tango_face_grin:


----------



## Osviur (Sep 7, 2015)

Hello Tabora,

Very interesting your power testing, thanks to let us know it . May it be possible to make an harmonic spectrum analysis ? . In the same conditions, with a fixed load, just resistive, any heating appliance, to see graphic and numeric results?. 

Thank you very much.


----------



## RedOctobyr (Aug 8, 2018)

tabora, that is a really nice setup! Great little shed for it. And thanks for sharing the AC-output test results, that's really interesting. Plus, that's a cool analyzer! 

Curious, do you know how well it maintains frequency? My Generac, with mechanical governor, suggested setting the governor to 61-63 Hz, I think, with no load. Then, as the load increased, it would drop to around 60 Hz. This seems like an area where an electronic governor could be a nice feature. 

My inverter generator always puts out 60 Hz, of course. But when a sudden load hits, the RPM drops before the electronic governor responds, which results in a voltage sag, rather than frequency sag. Though if I turn Eco mode off, so it runs at a higher RPM even when not required, that helps minimize voltage sags. 

Osviur, sorry, what is a harmonic spectrum analysis? I'm picturing something like an FFT (Fast Fourier Transform) analysis of the output, to show how much of the output is at 60 Hz, vs 120 Hz, etc? But I'm just guessing.


----------



## Osviur (Sep 7, 2015)

Hi RedOctobyr,

Sorry for the unclear term that I used, I am referring to the harmonic spectrum analysis test included in the Tabora Dranetz . It shows the different frequencies generated along the fundamental (60 Hz). In the graphic mode the voltages are shown as bars in the vertical axis and the frequencies in the horizontal axis . In the numerical mode the voltage values and their freqs. are shown as voltage units and Hz.

The fundamental frequency and its value (60 Hz 120 VRMS) is taken as the 100%, the second (120 HZ) ,third(180 Hz) as a voltage percentage with respect to the fundamental voltage and the sum of all harmonics is given as the THD.

All generators produce, along with the fundamental, other frequencies, not desired, difficult to measure, unless you have a power analyzer as this Dranetz.


----------



## tabora (Sep 6, 2018)

Osviur said:


> Very interesting your power testing, thanks to let us know it . May it be possible to make an harmonic spectrum analysis? In the same conditions, with a fixed load, just resistive, any heating appliance, to see graphic and numeric results?


Well, today there's 8" of snow on the ground and currently sleet and freezing rain on top of it. I'm waiting for it to subside so I can go out and fire up the snowblower (hopefully well before the Patriots/Chiefs kickoff). I'll do that next time there's either good weekend weather, or when the service is out and I'm running on the Powermate!


----------



## tabora (Sep 6, 2018)

RedOctobyr said:


> Plus, that's a cool analyzer!


 Yes, I purchased it as a non-working unit for $50 + shipping, and then purchased all the probes, etc. piecemeal on eBay over the past few months. Some minor tinkering and resetting later, I had it up and running. I still need to rebuild the Ni-Cad 12V 10 cell battery pack, which has a couple of bad cells. 

I used to borrow a 600 series Dranetz (no display, printer only) from DEC when I had power problems in my computer room back in the early 1980s which was worth several thousand dollars back then, and I had another older model Dranetz when I worked for Konica Minolta. I think I paid close to $8000 for it complete with all accessories, so I was quite pleased with this PP1; the older model only had a one-line display, so it was much less intuitive to use and had much more limited analysis capabilities.


RedOctobyr said:


> Curious, do you know how well it maintains frequency?


 Apparently pretty well, since the Dranetz didn't object when the air compressor was kicking on and off (I was using a die grinder at the time). I was mostly interested in the sine characteristics, so I didn't think to run the frequency analysis (what *Osviur* was asking about), but will try that at some point in the future when the weather is cooperating better!


----------



## RedOctobyr (Aug 8, 2018)

Osviur, it sounds like you're describing what I would at least call (maybe incorrectly) an FFT, thanks. It's interesting to learn how THD is calculated.

tabora, that's awesome. Sounds like a very cool machine. At first it seemed a bit like an oscilloscope, but clearly it can do much more analysis, vs simply *displaying* the waveform. 

I'm sure it can display frequency (if my $25 Kill-A-Watt can measure it). It would be interesting to see where the frequency starts, unloaded, and how much it changes as you increase the load. Setting aside momentary changes as the engine starts to respond to added loads. My Generac would drop by a few Hz with a decent load. I think I'd leave it set to 62 Hz unloaded, and it would sag to around 60 with roughly half its rated load. 

These discussions make me wish I'd hooked up my scope to the Generac before I sold it. As it is, I can't share any waveform data. Oh well.


----------



## Osviur (Sep 7, 2015)

RedOctobyr,

You are correct, this is just a fourier's application packed in a program to analyze waves.
I sent you a message.

Regards


----------



## tabora (Sep 6, 2018)

Just put my Powermate *PM0126000 *generator back to bed after 50+ hours run time the last three days post-Nor'Easter. It ran the entire house other than the oven, secondary water heater and clothes dryer. Averaged about 10-15 amps on each leg during non-sleeping hours, and 1/3 of that in the wee hours. The sine waves under load didn't look too bad, either (Dranetz printout attached). My 40/45Amp GenerLink meter-mounted transfer switch performed perfectly in its first outing. Sure an easy way to get power into the entire panel.

I had only put 3/4 hour on the Powermate during its first power outage before power was restored, plus 1/2 hour power quality testing as mentioned previously above. So this time it got an oil change, EZ Oil Drain Valve, and 7 fresh gallons of fuel with Stabil. Ready for the next one...


----------



## Predator (Sep 19, 2017)

Interesting.....
At the PowerMate website, the specs list this unit as NO AVR....
But in the parts list, there is an AVR listed.


I have an older Powermate 6250 that has some fairly noisy output. It won't even run my Frigidaire refrigerator.
From speaking to people at PowerMate, the older ones like mine had no AVR, but newer ones do. But personally, I think the newer units simply have better alternators.
Mine is about 12 years old.


Nice setup. so did all the unprepared neighbors come over to spend some "friendly, get to know you time" during the power outage? ;-)


----------



## tabora (Sep 6, 2018)

Predator said:


> But in the parts list, there is an AVR listed.


Mine (2017 model) does have an AVR.


Predator said:


> Nice setup. so did all the unprepared neighbors come over to spend some "friendly, get to know you time" during the power outage? ;-)


No, almost all my neighbors also have generators except my neighbor immediately to my left who had a 100'+ oak tree fall onto his house, so they were at a hotel. The folks he hired to clear all the oak pieces off his house and property just finally finished that job yesterday. Lots of cords of wood there! Now the carpenter is repairing all the damage.


----------



## tabora (Sep 6, 2018)

After hearing trees falling in the windstorm last night, awoke to no power today. Unrolled the 8-gauge and plugged into the GenerLink and the PowerMate started up on one pull. With the whole house powered (except the range & dryer) and one A/C unit running, only drawing about 1100Watts on one leg (with the A/C) and 580Watts on the other one. Made some coffee and am just sitting here waiting to see how long we'll be out this time...

Edit: Not too bad! Power came back on at 11:30. Now, off to work...


----------

