Shop Products
Houzz Logo Print
sniffdog

Troubleshooting Kohler 12RES Problem

sniffdog
13 years ago

I have a Kohler 12RES generator with an RDT 100 Amp Auto Transfer Switch.

Last week I noticed that my generator did not kick on for the weekly exercise test and that the red Source Available Light on the ATS was flashing rapidly. I tried starting the generator from the front control panel and the engine would not crank. When I put the generator on Run, all I heard was a rapid clicking noise and then nothing. No faults were displayed on the generator control panel. It did display a CC1 which indicates crank cycle 1 was attempted.

After troubleshooting per the manual, I discovered that the battery was dead  a 2 year old DieHard Group 26 which I thought was odd. I took the battery to Sears and they tested it  found it was bad. Bought a replacement, installed it, and was able to start the generator from the front panel. I cleared the fault on the Automatic transfer Switch per the manual and tried to run the generator remotely from the ATS panel using both the Exercise and Test buttons. In both cases, the generator started, ran for a little over a minute, and then shut down. When the generator stopped, I heard that rapid clicking noise again and then nothing. I looked at the front panel on the generator and noticed that it received a Stop command from the ATS. Generator Source red LED flashes rapidly after each start and then shut down. I repeated this process 3 times and same result each time.

The flashing red LED indicates one of two faults: Failure to Acquire Standby Source, and Failure to Transfer. Since both tests I ran were with no load transfer, I believe the first fault listed is the one. This fault occurs if the transfer switch does not sense voltage from the generator set within 78 seconds after signaling the generator to start.

I checked the output voltage on the generator terminal block and found that one side is putting out between 125 to 126 volts, while the other side is only putting out about 26 to 29 volts. It appears that the ATS is sensing that the wrong output voltage is being produced by the unit and automatically stopping the generator  as it is supposed to.

I attempted to adjust the output voltage by programming the controller and could increase and lower the side outputting normally from 125 up to 138, and then back to 125 volts. But the other side did not change  remained at a constant 29 volts during this test.

Does anyone have any idea which components on the generator could be causing this problem and how I can safely isolate which component is bad? It seems like it could be a bad voltage regulator and if so, I wonder if that component be replaced without replacing the entire controller? I am hoping this isn't something horribly wrong with the unit.

Thanks

Comments (21)

  • wayne440
    13 years ago

    It is probably not the regulator, as a regulator issue should affect both sides of the phase, not just one. Look for an open connection between the generator end and the terminal block. A loose terminal or bad breaker etc. If you dont find anything, time to look inside the generator end.

    What kind of meter are you using? If it is a digital meter, the 29 volts is probably just inductive voltage. You may benefit from an old fashioned analog meter, Wiggy or test light.

  • sniffdog
    Original Author
    13 years ago

    wayne

    thanks - I am using a digital meter. I found out that there is a Silicon Controlled Rectifier device inside the generator controller box. This device is controlled by the main computer and is used to adjust the output voltage of the generator.

    I pulled the unit and ran through a series of tests using a procude I found in a Kohler Marine Generator service manual that happens to use the same type of ADC contoller that is in my unit. My SCR unit failed one of the test steps - so I ordered a new part. The service manual said to check this device (plus fuses) before replacing the main computer. I am hoping this 50 dollar part fixes the problem.

    Once I get the part installed and tested, I will post the results. I will also check all winding and controller cables to make sure none have vibrated loose.

    Along my searches on-line, I found a great source for Kohler generator parts: www.partsfortechs.com (or ASAP parts)

    I was able to order the SCR as well as a Service Manual for the Kohler 12RES generator which I have been looking for quite some time. Once I get that manual I will be able to perform more detailed troubleshooting and maintainence. It seems like Kohler works extra hard to prevent the DIYer from doing anything more than changing oil and filters on the residential generators. The problem I have found is that the authorized Kohler service companies in my area charge exorbitent rates to come to the house just to look at the box, let alone repair it.

    Even if the SCR isn't the issue, I want to pinpoint the problem so if I need to call in a service company I can tell them exaclty what the issue is.

    Thanks

  • wayne440
    13 years ago

    Out of curiosity more than anything - is the dead side of the phase the same one that was a bit low when you installed the set?

  • sniffdog
    Original Author
    13 years ago

    I replaced the SCR module but that did not fix the problem. I also checked all wire connections and fuses again and found nothing wrong. I decided to call an authorized Kohler service company and they are coming Monday morning to look at it.

    It is very odd that the ADC controller on the unit is not sensing an under voltage condition and issuing an alarm code, yet the transfer switch controller is sensing the wrong voltage and is issuing the stop. I am wondering if the ADC controller on the generator is bad.

    I don't remember what the readings were after I installed the unit and did the startup checks.

  • huntermn
    13 years ago

    I would love to know what the Kohler tech discovered. I am having the same exact issu on a unit that is located in a VERY remote location, so getting a tech there is almost impossible.

  • Contactcyrus_Hotmail_Com
    12 years ago

    Had a similar problem on a marine kohler. After two weeks with a tech and taking apart the whole back end, replaced the scr module and controler unit, also getting funky readings from windings, turned out to be a fuel restriction problem. Aparantly makes the fancy controler go haywire. It's worth a check.

  • Daniel Bruse
    7 years ago

    I too am having the same issue with my unit. When I press the switch below the red flashing LED on the ATS panel there is no response. If I trip the whole house master breaker the generator started and ran normally but would not shut down once I reset the whole house breaker. I had to switch the Generator set master switch on the outdoor unit to stop the engine. I can manually start the unit with the "Generator set master switch" on the outdoor unit. I am not sure what to check now? I am about 3 hours from the nearest service center so I am hoping to resolve the issue without a service call.

  • Mike C
    7 years ago

    Even though the battery is new, could possibly need to have an initial charge? The clicking of the solenoid seems to indicate not enough power (from the battery) to crank over. Could the new battery be bad?

  • iceshack
    6 years ago

    my 12 res propane generator just stated running for 10 seconds and then shutting down. the display showed UV under voltage. after resetting it would do the same thing again. during the ten second run it didn't put out voltage. any ideas?

  • Craig
    6 years ago

    I have been having the same problems for over a year. The unit fails when it is suppose to run the exercise. Getting exercise not scheduled error, then later I get exercise not scheduled and time and date not set, and after a while it shuts itself down. Have had two control panels installed and a new battery. The company that is suppose to repair it is still looking into it and also going through Kohler to find a solution. Sounds like they have a lemon on there hands.

  • Eric Tinsley
    5 years ago

    We now just started experiencing the same problem. The technician came out and said we need a new controller on the unit. They are supposed to be calling back with a price. I am sure it will be expensive. Has anyone figured out the cause? I hate to buy a new controller and that not be the issue. Already replaced the battery and ruled out any other issues. There is power to the controller, but the controller unit is dead. This all started when I replaced the old battery with a new one.

  • HU-312896963
    5 years ago

    The ATS board on my 12RES 100amp propane has failed twice since the 12/2008 install. Fortunately on the 1st failure I was within 2 weeks of the initial 5 year OEM warrantyexpiry (or cost to replace would've been $425.00....then in 2013). Update: since running live in June 2018 power outage, noticed that unit failed to revert to weekly excercise. The gen. responds successfully to a manual on/off at rockerswitch on unit. And when I perform a manual live load at the main, the ATS turns the gen on within 6 seconds....then a 10-12 min normal shutdown after I switch the main back on. Good news? ATS communicates to gen. Bad news? $Cost to replace approx $450.00. As long as I continue to test as mentioned, all is swell. BTW, warranty on aftermarket RDT board is only 120 days.

  • Shirl Kobler
    4 years ago

    Have problem with the generator not doing exercise also. Had new starter put in, new battery, new plugs, oil filter, oil, and air filter (?). Notice that the breaker in the unit seems to move to the middle and then shut off. Had code oc before, not cc1. Unit is not new, but not vintage either. Up to this summer, ran as it should. Had the mother board replaced about 3 years ago. Solution anyone?


  • Craig
    4 years ago

    The problem is that the unit vibrates and it causes the control panel to loose power. There is a bad connection somewhere, my opinion. After a long period of going back and forth with them, I don't think they believed that is was happening because the control panel did not show an error that would cause it. The only error I saw was that the exercise was not set, then the time and date was not set, and finally it turned itself off. Their solution was to pad up the control panel so that it would not vibrate enough to cause the problem. It seems to work so far. The only other problem I had after that was the automatic choke wasn't working properly and the unit failed to start. I called the company that was suppose to repair these units and was told that it was probably too cold outside. But other than that the unit has operated without shutting down. So in my opinion the control panel has a possible bad connection, so it causes it to loose power when the motor runs and vibrates it too much.

  • Gene Shaw
    3 years ago

    I just installed a new 2100adc controller on my 12res and the output voltage reads 120, 60 on each leg. Is there a way to adjust this, or is there a problem with the generator? Thanks. gs69camaro@hotmail.

  • HU-648031672
    3 years ago
    last modified: 3 years ago

    I am having the same problem with my 12RES. I changed the controller and now only have 120 volts between the 2 hot legs. (60 +- on each leg to ground. I tried adjusting the voltage with the controller but it would only go up to about 136 v.

    Update: I went into the Controller Configuration Procedure to check the voltage setting and it was set to Uu00 instead of Uu01 as it should have been. After changing this setting and saving the setting, it works fine.

  • George Cramp
    2 years ago

    I also have a similar problem as many of you have described. When power goes out the generator will start and immediately shut down. It will cycle through this start/shut down repeatedly and never show a code fault. I get a rapid flashing red light on the transfer switch. I can manually switch from auto to run and it performs great providing power. Just not on auto. it seems as though the problem has progressed. Initially it would run when on auto and then sometimes not, or run for a few minutes before shutting down. Now it won't run at all after initial start up. Just shuts down. Any thoughts? Thanks to all.

  • PRO
    Wright Construction
    2 years ago

    I believe one of the capasitors could be the problemblemish.

  • HU-574500711
    last year

    My 12RES is doing the same thing as George Cramps. So, I did a complete service (plugs, oil, filter). It worked for about two weeks. Now back to the same old thing. Cranks, runs for about 5 to 6 seconds then shuts down. Will not restart.

  • HU-468931388
    11 months ago

    miriam miller, I to have the same problem. during hurricain fiona, I was wthout a generator for 10 day. I burned 3 batteries in 10 days. my generator is not even a year old. my second problem is big fuel usage, very loud unit as well. kohler people have been very unhelpfull. the authorize dealer have tried to help with no results. I am stuck with a bad product. stay away from this product. I live in fear sinceI livein puerto rico, where bad weather is commom.