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Serpentine drive off flywheel?

Started by WGB, November 19, 2009, 03:25:05 PM

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WGB

Now I need some help Veggie.
The VOLTmaster head and engine stay with-in 10 or so RPMs, voltage is in the 120s, but the hz is from low 50s to 68, with no load change.
It will handle load changes like a champ voltage wise, but frequency is all over, load, or no load.
How does yours run?

veggie

WGB,
Using a kill-a-watt, my hertz only changed when the engine speed changed.
The hertz can only be adjusted by varying the rpm. (The frequency at which the poles are intersecting the mag fields).
I would start by monitoring how the governor is reacting as the loads change.
Secondly, how are you measuring the rpm?
A drop of 10 rpm could not move the generator into the low 50hz. range. To drop to 50hz, you would have to reduce the head rpm by 20% down to 3000 rpm.
This looks like a speed issue and not a generator head issue.

keep us posted,
Veggie


WGB

I'm using a Kill-a-watt and digital tack.
Never saw it at 3000 RPM.
I'll give it another go as soon as I get a few minutes.

BruceM

WGB,  I'd suspect a problem with your digital tach- maybe a shiny spot on the flywheel is confusing it, thus the fluctuating readings. 

veggie


Something else just occurred to me.
Check your belt tension.
Belt slip when under load can cause hz. variations while the engine speed remains constant.
Just grabbing at straws...but you never know !

veggie

flywheel

Quote from: BruceM on December 24, 2009, 05:19:46 AM
WGB,  I'd suspect a problem with your digital tach- maybe a shiny spot on the flywheel is confusing it, thus the fluctuating readings. 

Try your digital tach on the generator pulley rather than on the flywheel. See what kind of fluctuations you may have checking it that way.  flywheel
Never met a diesel engine I didnt like.

WGB

Today with the tach on the engine or on the gen head sheave I'm seeing a less than 10 RPM fluctuation.
I adjusted the belt and let the unit run for 10 minutes or so before checking.
Things are better, like I said RPMs less than 10 RPM fluctuation, frequency is 58 to 62.
If I'm looking at this right that would be 240 RPM variation.   3600*60=60x4=240RPM
Same test instruments on the ST and Listeroid give me right what I would expect.
Maybe my tach is off at higher RPM.
ChangFa clone & VOLTmaster 2200 & 3600 vers Listeroid & ST at 650 & 1800

veggie

WGB,

That's looking a bit better.
I suggest it my be the measurement equipment.
If the rpm is only varying by 10 or so, then the hertz is in line.
As far as I know, HZ cannot vary if the speed remains constant.

veggie

WGB

Hey Veggie and everyone,
  I haven't worked with this generator for couple months.
I used it today, I still have a weird Hz thing going on.
Everything running up to speed, 61 something hz, I throw a 1000 watt universal motor load on, RPM drops, hz jumps to 75hz?
How the heck can that be?

veggie

WGB,

Try a resistive load like a 900 watt element heater. It's non fluctuating and stable.
Also try it on both of the plugs on your gen head to see if there is any difference.
Like Jens said, making 70 hz. with a generator turning at 3600 rpm is ....well....impossible. ???

veggie

WGB

Quote from: veggie on May 13, 2010, 09:52:13 PM
WGB,

Try a resistive load like a 900 watt element heater. It's non fluctuating and stable.
Also try it on both of the plugs on your gen head to see if there is any difference.
Like Jens said, making 70 hz. with a generator turning at 3600 rpm is ....well....impossible. ???

veggie
[/quote

You would think so,i can put the same loads on my Listeroid is rock solid.
If I run straight resistive loads, it still fluctuates 10 hz or so.
That head is supposed to be 5% or less total harmonics.

This is a grasping at straws but:
That is an electronically controlled unit, any possible way its screwing up?
VFD change  hz electronically.


Carlb

I have had similar issues with a Kill o watt meter.  Sometimes it reads correctly at 60 +/- 1 but sometimes for no apparent reason with the same load it will read 35hz which i know is not accurate.   I also have a freq meter on the gen head and it never varies more than 1 to 1.5hz. 

I would suspect the meter is faulty especially if you are only seeing a 10 rpm difference in speed.
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XYZER

Quote from: XYZER on April 04, 2010, 10:08:37 AM
Blink,
Thanks! I might still use the generator head if it will run my 1/2hp submersable pump at the ranch. The head has an issue with the hertz. 60ish on one side and 40 on the other. It will run heaters and lights ok. I am trying to keep it as light and small as possable. I will also add a 160 amp 12volt alternator to charge my battery bank. The hertz thing has me puzzeled???? Do you think 4000watts will start and run a 1/2hp?
Dave
I have one that does the same thing. It seems to work OK......
Vidhata 6/1, Power Solutions 6/1, Kubota Z482

WGB

Ok thanks, guys.
I'll check with a multi-meter this afternoon!

Tom Reed

It is possible that the wave form your generator is creating is right on the edge of a double trigger of your hz meter due to a misshapen or spikey output.
Ashwamegh 6/1 - ST5 @ just over 4000 hrs
ChangChi NM195
Witte BD Generator

Tom