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Discussion Starter #1
Hi guys! Start off by saying reading around the forums has helped better my understanding of these tools.

I recently was given this beast of a generator, Kohler 60kw Diesel.

She starts up fine, as long as there is diesel no problems! The problem comes from voltage. For the past couple of days I have been trying to diagnose and fix the issues.

Whenever I test with the multi-meter on any of two leads I get a large fluctuation between 70-130 volts. Same thing when measuring from one of the 3 leads to ground.

First was to clean up some nest that was inside the control area, apparently it had fried some wire on one of the relays. I fixed that but it didn't solve my voltage problem.

I played around for a bit testing all the relays and cleaning her up but didn't find a solution until I thought to play with the throttle a bit. If I run the throttle full blast I am getting the full 220v from probing two of the 3 leads on the breaker and 120v when probing from 1 of the three leads and ground.

You could say problem solved, however this will consume a lot of diesel, produces a lot of white smoke, is much much louder than any lower throttling/idle and previous owner said that he never needed to full throttle it for proper voltage. That last bit I suppose he could have been mistaken....

Is it possible the voltage regulator is toast?

I found a replacement online, however it is pricey.

https://www.colburnpower.com/kohler-generator-parts/kohler-part-b-269735-voltage-regulator.html

Any input is welcomed as I am just learning about this beast and most of my electronic knowledge is in low power DC circuit building, arcades etc.

Thanks!
 

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please post the serial number and model number.
also post the numbers rating plate.

is this a 240 volt or a 208 volt??
also the knob on the pot for the voltage adjust is missing..
is the pot or voltage adjustment rheostat ok?
I am thinking at first thought this might be a 208 volt unit..

see the install setup manual for this unit...
there maybe a buss bar setup to select the voltage and hz.
most of these were for industrial places.
 

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Discussion Starter #3
You are correct that it is a 208v generator.

I have no idea teh model number, could not find anything like that. The motor (not engine) says Kohler Electric Plant, there is a plate on it with more info. I will get a picture of it tomorrow morning for you. I believe it says 1600rpm.

I have not checked the voltage adjustment pot, I have turned it back and forth with no visible change on the multimeter.

Thanks a lot for helping, quick response so far!
 

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This is an 1800 rpm set: 1800 is its rated speed; 60 hz rated frequency.
Let's start with the good news: These old mechanical relay sets are relatively simple, durable, can withstand a lot of malfeasance and abuse, and many times can be diagnosed just by looking at things.

Now, you state, "full blast". Not sure what this means. Typically, these sets have a governor and a fixed speed; some don't even have a throttle handle or knob or any other means of adjustment. Most of these sets -not all, but most- accelerate to rated speed when started, there would be no 'idle', per se'. You should see the frequency meter centered on 60 hz as confirmation that the engine is running properly.
If the engine is running too slow the voltage regulator will not work properly until the engine is running at a speed close to 60 hz - let's call it something above 52 hz.
In the photo where you have the engine running, and showing a low voltage reading on your DVM, you'll notice that the frequency meter (upper right hand corner) is off-scale at less than 55 hz. You can't test the voltage regulator until you get the speed somewhere on that meter.

IS that what you mean by "full blast"? That you have to set some throttle at 'max' in order to get 60hz?
 

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also, it might be helpful to include a photo of the throttle you are adjusting. The injector pump, too.
 

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Discussion Starter #8
Here is a few more pictures, thanks.

208 line is showing around 120hz, but is jumping around. The 110v line is showing 62hz steady.

That has to be bad right? All the electronics I am trying to run are 50/60hz 110-240v

I managed to adjust the throttle to where it now produces steady voltage around 75% throttle.
 

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do you have a hand held contactless tach yet??
you need one to look at the rpm on the diesel part...
put the reflective tape on the crank balancer.

cool these days as they are cheap!!

last I knew these were " fixed rpm" to get the hz.
they are adjustiable and have a electrical to mechanical governor to keep the rpm steady for the load changes.
but the hz needs to be right about center of the 60hz...

last I knew unless you are setup for 208 on your L1 to L2 load you need an accy transformer to change that to
single phase L1 125 vac to neutral L2 125 vac to neutral and L1 to L2 as 240 vac...
maybe something like this https://store.maddoxtransformer.com/products/240-delta-208-y-120?variant=45588273993

but on most late trailer units I have worked with they also have different taps for output
and shorting bars to "program" or "select" the gensets outputs.

are there any printed paper tags inside the side covers?

the tag on the generator alternator or "head" is just for that unit..
but some times unless the head has been swapped out you can track that back to the gensets model and serial number with a call to the mfg.
on the older stuff it is all "hand check"
now days after 2006 mfg most of it is all in a data base some where...
unless the mfg had folks enter the data for each model and serial number if they were all option units during production.
back then most of the larger units were just that!!
made to the clients specs on demand...

yea we need to know more on the head wiring...
I suspect it is a 208 Y 3 phase style..
but it could have the correct taps for 240.
 

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There's many unknowns as you present. Such as:
Where are your meter leads attached?
Is the output ckt breaker closed? (if not, you need to probe directly on the alternator leads before accurate readings)
Is this a brush or brushless alternator?

Here's what I can deduce from the limited info: This is a 208 vac, 3-ph, 1800 rpm set. It sounds like the engine is running at least close to speed.
Here's what I suggest: Get the engine to run at 60 hz as indicated on the meter panel. Next, put the handheld meters away for now. Instead, trust the panel voltmeter (top left) to confirm output voltage as you rotate the selector switch between all positions.
Report back your findings.

Again, if you are probing the output leads withOUT the on-set breaker being closed your digital voltmeter will give incorrect values that tend to bounce around. Especially the frequency, which, in my experience, will tend to read in multiples of the base frequency.

EDIT: looking at one of your photos I notice the onset ckt bkr is in the open, or off, position. I also notice the top output leads have been cut. So, where are you probing with your handheld meters? (hint: you need to be probing the bottom breaker leads, those that are coming from the alternator.)
One more thing: Would you happen to have a Fluke digital meter,or equal? Don't mean to disparage your equipment, but, I've seen some strange "problems" that got back to the measuring equipment being used. I don't that's the case here, but, for now, at least, I'd rather trust the onset metering. We can get back to your handheld meters later.
 

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OP You have been given some miss information. The no load speed for that unit should be 62.5 hertz as that engine governor is at best a 5% droop. Until you start at the beginning you will be running in circles. Units that far back may or may not have an under frequency roll off, built into the Voltage regulator. That should be a 6 coil stator which will make many different voltages be they single or 3 phase, depending on how it's terminated. When working on anything always split the system on half, if you have what you need mid way the issue is down stream, if you don't have what you need at ;mid stream why would you expect the remaining to operate properly? If it's not at that mid point split that point again. Test don't guess. I can not see all of photos/links that you posted as I will not allow all the scripts required to run on my computer, however I did see enough of the you tube video to see what your working on.
 

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@KRE, no mis-info; the set isn't yet running under load. We can get to the finer details, such as droop and wiring configurations, later.
But for now, we're simply trying to understand the OP's complaint and what would cause it. #1 in my mind is to get the set running at close to rated speed, then start probing from there.
The good news is that from the video the engine sounds healthy. Also, at just 600-something hrs on the hour meter this is a relatively low-time set.
 

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@KRE , no mis-info; the set isn't yet running under load. We can get to the finer details, such as droop and wiring configurations, later.
But for now, we're simply trying to understand the OP's complaint and what would cause it. #1 in my mind is to get the set running at close to rated speed, then start probing from there.
The good news is that from the video the engine sounds healthy. Also, at just 600-something hrs on the hour meter this is a relatively low-time set.
Does not matter wither it's running no load or full load. If the prime mover is not operating properly the Alternator is never going to operate correctly. Trying to solve an issue by jumping around in a system never yields timely or proper results. Just a little I leaned in the 45+ years of working in the EPG (electrical power generation) field. The basic principles of EPG are the same be it a rope start, large resip, steam or Gas turbine set.
 

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KRE, in this case it does matter because his issue isn't one of loading. Do we even know what the issue is, for a fact?
The first thing I want to know is the engine is close to rated speed - doesn't have to be perfect 60 hz. 62 or 58 is close enough. agree?
Next thing I want to know is where is the OP probing? He's never really said.
Lets be cognizant of the possibility that the OP doesn't seem to be experienced, so we should not be ripping & stripping - one thing at a time, which, to me, is to understand the basics.
By the way, 42 years in the power field here, too. Large and small AC & DC plant; batteries; inverters; converters; ac & dc switchgear; gas, diesel and gas turbine prime movers; analog and digital controllers.
I'm a master of none, certainly no expert in any. But, I've been involved with a lot of stuff and try to be helpful.
 

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- doesn't have to be perfect 60 hz. 62 or 58 is close enough. agree?
Do not agree as I do not know where the UFRO knee point is set, should it have one. Nor do I know the percentage angle that it has. It could be found quickly with a meter or scope. Again if the prime mover is not up to snuff, everything down stream will not be either. I have seen too many people chasing their tails an waiting time/money over very simple issues, like this. The Kohler excitation system is unlike most others, as it uses an FR activator an a PMG power supply. If this unit is like I think it is, all the voltage reg does is turn on an off a single LED that adds or subtracts light to a rotating photo board. That broad adds or subtracts voltage to the FR activator SCR's, that power the main rotating fields. The Sensing leads just supply voltage to the voltage regulator to allow the reg to add or subtract battery power to the LED. It is a closed loop system which is different than any other PMG style gen ever made. The magnets are stationary an the exciter rotor just spins inside to supply the FR activator.
 

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Discussion Starter #19
"Lets be cognizant of the possibility that the OP doesn't seem to be experienced, so we should not be ripping & stripping - one thing at a time, which, to me, is to understand the basics."

This is correct. Doing my best with the limited knowledge I have on generators of this kind. I am enjoying these lessons though. You guys are great.

I seem to be closing the issues that pop up so far. I am no worried about the fluctuating "hz" readings I am getting. I do not want to damage the Ballasts I am running.

I will take another video in the morning, probing from all points, using both the true rms meter and the smaller one to provide more clear info. This machine is a beast with very few operating hours on it and I would love to know all about it.

The load will be approximately 30k watts. I was also planning on using a "V2 AutoGen 12v auto start generator controller." to remotely start it or on timer as needed.

Thanks guys
 

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Discussion Starter #20
I forgot to mention that there is white smoke coming from the exhaust, not very thick but noticeable. From what I have read, this is not a good thing to see. How should I address this? Thanks again
 
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