Generators and Motors
[Home] - [HELP] - [Forums] - [Articles] - [Photo Gallery] - [Groups] - [Chat] - [Classified Ads] - [Subscribe] - [Links] - [Books] - [Sponsors] - [Tools]

Go Back   SmokStak > SmokStak® Vintage Electrical Equipment > Generators & Motors General Discussion > Kohler Generators
Forgot Password? Join Us!

Notices

Kohler Generators Restoring, maintaining and operating vintage Kohler generators.

Kohler Generators

Kohler 50RZGB Intemittent low speed


this thread has 5 replies and has been viewed 1664 times

Reply
 
Thread Tools Display Modes
  #1  
Old 01-31-2012, 10:34 AM
DPeterik DPeterik is offline
Registered-I
 
Join Date: Mar 2011
Location: Two Rivers, Wisconsin
Posts: 74
Likes: 9
Liked 25 Times in 24 Posts
Default Kohler 50RZGB Intemittent low speed

Model# 50RZGB s/n 2100715

This unit has an intermittent run issue. Once in a while during an exercise start the unit will start but only runs at 900-1000 rpms and then will shut down on "aux fault". But once it is reset it does not happen again for a while, and you manually start or test start from the transfer switch and it will start and run fine. A couple of weeks to a month later it will do it again.
This is a LP liquid system. The converter had leaked coolant and was replaced with OEM. Both fuel shut offs were replaced at the same time.
Mixer moves freely, mag pick up is good.
Have any of you Kohler techs come acrosss this before? If so any diagnostic tips. I only have the operators manual and wiring diagrams, no service or diagnostic manual.
If some one has a service manual for this I would apreciate it, as I have more of these units I service.

Thanks

Dave
Reply With Quote
Sponsored Links
  #2  
Old 01-31-2012, 10:19 PM
Jim Rankin Jim Rankin is offline
Registered-III
 
Join Date: Nov 2004
Location: Faunsdale, Alabama USA
Posts: 4,084
Likes: 42
Liked 1,106 Times in 882 Posts
Default Re: Kohler 50RZGB Intemittent low speed

electronic governor? I am assuming so from the mention of a magnetic pickup. Have you checked and perhaps removed and replaced all the connectons to the control board, throttle actuator and magnetic pickup?

When you exercise it does it pull a load?
Reply With Quote
  #3  
Old 02-01-2012, 12:13 AM
Mikey4026's Avatar
Mikey4026 Mikey4026 is offline
Subscriber
 
Join Date: Jan 2008
Location: Eatonville, Washington
Posts: 554
Likes: 237
Liked 177 Times in 125 Posts
Default Re: Kohler 50RZGB Intemittent low speed

Does it have an external linkage from governor actuator to throttle lever?
I ran into a generator doing the same thing back when I was a service tech. The minimum throttle screw had fallen out, the throttle plate was sticking in the closed position and the governor could not overcome it. Putting in a new screw with a jamb nut solved the problem. I adjusted it to open the throttle just enough to prevent sticking.
Something easy and simple to check.
Regards
Mike
Reply With Quote
  #4  
Old 02-02-2012, 09:54 AM
EricWood's Avatar
EricWood EricWood is offline
Registered-III
 
Join Date: Oct 2005
Location: West Concord, Minnesota USA
Posts: 1,522
Likes: 181
Liked 969 Times in 534 Posts
Default Re: Kohler 50RZGB Intemittent low speed

Dave,

Those intermittent problems are a PITA to troubleshoot. Like intermittent driveability issues with cars.

Sounds like it doesn't come off of idle, when the event occurs. As Jim eluded to, I would start by inspecting the MPU for chunks of iron. May be flecks in there flying around, and randomly get stuck across the magnet, shorting it out, but rusty enough that the air turbulence of the flywheel teeth eventually blows them off. Check the ohms of the MPU, clean, readjust, and check MPU cranking voltage. Ohms should probably be anywhere between 180 to 250ish ohms. Cranking voltage should be in the ballpark of greater than 1.5 volts AC.

If MPU is clean, then perhaps the governor connections need looking at, or else the governor controller output drivers are failing. That will be a hard one to diagnose unless you can get symptom to repeat while you are there. I don't know if repeating numerous starts/stops would get it to occur for you while on site or not. Use two meters, one to monitor MPU voltage (AC), and the other to monitor actuator driver voltage.

Don't know if this has separate governror controller and actuator or not. Could be something as simple as Mikey mentioned, too. Also, if an integrated governor (such as a Woodward L-Series), check the butterfly plate for signs of that greasy, oily residue. Maybe sticky enough in cold weather to "glue" it shut momentarily, until vacuum breaks it free. The fact that it can only happen once, and usually after a period of sitting static, tends to make me think it might be something mechanical like this.

eric
Reply With Quote
The Following User Likes This Post:
  #5  
Old 02-02-2012, 07:13 PM
DPeterik DPeterik is offline
Registered-I
 
Join Date: Mar 2011
Location: Two Rivers, Wisconsin
Posts: 74
Likes: 9
Liked 25 Times in 24 Posts
Default Re: Kohler 50RZGB Intemittent low speed

This unit has an LC50 Woodward integrated controller/actuator. I have downloaded the software for this, but have to wait for the adapter harness, since Kohler did not install a RS-232 serial connector to the controller. I am going to reprogram it and monitor it as it runs under load.
I will let you guys know what the issue was with this.
Reply With Quote
The Following User Likes This Post:
  #6  
Old 02-03-2012, 09:29 PM
Mikey4026's Avatar
Mikey4026 Mikey4026 is offline
Subscriber
 
Join Date: Jan 2008
Location: Eatonville, Washington
Posts: 554
Likes: 237
Liked 177 Times in 125 Posts
Default Re: Kohler 50RZGB Intemittent low speed

Dave

I suspect you may have an intermittent MPU signal, as the gen at least will start.
Once you get connected to the governor, the software will show you why it is not coming up to speed if you can create the problem. If you don't find any MPU problems look into the settings.
Setting up the L series can involve quite a lot of fiddiling, there are a lot of settings.
I would recomend looking at the settings on one of your other units and comparing them. Save a file from a gen that does not give you any trouble and flash it into the troubled unit if all else fails.

My information may not be totaly correct as I have not touched one in two years and am working from my feeble memory. Gunny can offer more information and can put you in contact with someone that is an L series wizard if all else fails.
Good luck
Mikey
Reply With Quote
The Following User Likes This Post:
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
Kohler 50ROZ 281 Engine Speed Problem sportmodel Kohler Generators 9 09-08-2011 10:20 AM
Question about Generator Speed and Motor Speed iceman Generators & Motors General Discussion 7 06-12-2010 02:08 PM
Kohler gen 3.5 mm 25 speed control TISTAB Kohler Generators 9 10-27-2009 09:30 PM
E-speed Ihorse Antique Gas Engine Discussion 1 07-12-2005 12:08 AM
generator speed Joseph Turrisi Generators & Motors General Discussion 7 11-21-2004 11:44 PM


All times are GMT -4. The time now is 10:28 AM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark
A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2014 by Harry Matthews
P.O. Box 5612 - Sarasota, FL 34277