Rotoverter Initial Idle Results

[oouthere]

  Just info on the rotoverter I've started.  The motor is a remanufactured 7.5 hp unknown model with squeeky bearings.  It is a 230/460vac, 3450rpm motor wired for 460 but run with 121VAC line voltage.  I am using mainly new capacitors but a couple are old. These are the MFDs:  3, 4, 5, 7.5, 10, 30, 50, 149.  The motor takes about 5-10 seconds to spin-up using the 149 as a start capacitor and then switching it out.  I built a test bank with STDP switches to completely isolate the caps during testing.  The motor was allowed to stablize for about 30 seconds to a minute before accumalating the data.  Some of the measurements would bounce alot so I took the highest and lowest that read on the amp meter (2% accuracy on 40 amp scale) at least three times in 30 seconds.  Here are the results:

mfd    amps

  0     1.5
  3     1.4
  4     1.8
  5     1.7
  7.5  1.6 to 1.5
  8     1.6
  10.5 1.5
  11.5 1.55
  12    1.53
  12.5 1.27 to 1.45
  13    1.29 to 1.38
  14    1.28 to 133
  15    1.24 to 138
  17    1.24 to 1.34
  17.5 1.16 to 13
  19    1.07 to 1.22
  20.5  .98 to 1.19
  21.5  .86 to 1.07
  22.5  .86 to 1.02
  24.5  .82 to 1.02
  25.5  .88 to 1.02
  26.5  .8 to .84
  29.5  .77 to .96
  30     .76 to .86
  33     .77 to .87
  34     .78 to .82
  35     .8 to .86
  37     .88 to .94
  38     .93 to .94
  39     .97 to 1.04
  40     1.04 to 1.06

  Best run is .82amps x 121VAC = 99.22 VA

  I have a 12KW generator head but it is to large for such a small motor to drive for a load.  I bought a 1200 watt generator just for the head but the crankshaft is also the generator head shaft so that's a no go also.  I do have an old 3.5 compressor motor that uses caps for starting....does anyone know if anything special would have to be done in order to use this as a generator head?  Any ideas that do not cost a lot of money and are easily adaptable will be greatly appreciated 

  Rich

[ashtweth_nihilisti]

Have you tried Frequency driving you RV yet?, it can reach up to a higher Hose power this way and maybe drive some thing near that, this way (Freq driving) the ZPE pulse width modulation states come in handy

Search on this compilation for frequency drives
http://www.panacea-bocaf.org/files/RV%20energy%20saving%20applications%20and%20R%20and%20D.pdf

Regards
AShtweth

[oouthere]

No, I've been using commercial 120VAC @ 60hz.  From what I've read you should be able to make it work on straight line voltage.  I did buy a rebuilt 84% effeciency Baldor 5hp, 1800 rpm motor for the generator that is coupled 1:1.  I have not built my load circuit (100 watt bulbs) yet but this is pretty fun.

Rich

[wattsup]

@oouthere

Good work. Once you have your cap bank on switches, life is so easy.

Here is a picture of my set-up I have been testing off and on the RV from DC-DC motors in loop, to AC-DC in loop, AC-Alternator now my next one is the AC-AC.

What is the rpm rating of your 12kva motor at that voltage. If it is low enough, you could try 2:1 or even 3:1 gear ratio.

My next tests will be with a very very larger coupler to give the prime mover some added inertia to fight against the drag.

I have tested with a 5ph leeson running a 108 amp alternator which I have simply modified the regulator to be able to apply the excitation voltage myself. The alternator won. There is too much drag and the prime mover starts heating up, even if you try other cap configurations.

The main problem with RV is it will be good under light loads but when you start asking more, it lacks the torque. From 5ph the RV renders the motor around 1.8hp or even less I am sure.

My capacitor bank holds 15 caps with 17 switches. Switch 1 is the main, swithches 2-9 are bank 1, switch 11 is bank 2 main, switches 12-17 are bank 2. This allows you to quickly find the start values, and when the motor runs full you can switch this side off and use the others as run cap.

[ashtweth_nihilisti]

Guys don't forget the extraction circuit you can use on your prime mover (tested in France and working to charge a secondary battery for free) or (untested) on your alternator.

there are step by step instructions on the RV peswiki page or in the compilations on this page, please sign the petition for now energy wastage in 1.8horpower motors and support the RV, its as easy as name email country thanks, helps us help you.

Peswiki RV
http://peswiki.com/index.php/Rotoverter

Support the RV here and Sign the no energy wastage
Petitions- http://www.panacea-bocaf.org/RotoVerter.htm

neon