Question about Kohler 12 kW Emergency Power System - 12RES-L

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Displaying OC after repeated weekly self-test attempt; manually starting generator at gen-set panel immediately after said failures works fine.

Posted by Jeff Frontz on

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  • Jeff Frontz Aug 07, 2011

    Almost exactly a year ago, the exact same thing happened -- after the unit failed its self-test several weeks in a row, it also failed to spin-up during an outage; the tech who came out found that the the GM34969 ADC Controller was oozing red goo and claimed that it was intermittently failing to send power to the starter solenoid.  He replaced the controller and said things were OK. Unfortunately, he forgot to reschedule the weekly self test and I didn't reset it until I noticed many months later that it wasn't happening. Consequently, the gen set panel reads only about 9 hours of operation.

  • Jeff Frontz Aug 07, 2011

    The indoor control panel flashes indicating a fault -- the panel on the gen set flashes "OC". If I then move the rocker switch on the gen set panel from "auto" through "off/reset" to "on", it starts up without a problem. If I then go back inside and manually start/schedule the weekly test, it works fine that time, but fails the next week.

  • Jeff Frontz Aug 07, 2011

    The one thing in common between now and a year ago is that we're again experiencing incredibly hot/humid weather.

    Previously, the ATS was replaced for failing to switch one of the phases (another thousand dollars or so).

  • Jeff Frontz Aug 07, 2011

    I've tried contacting Kohler and they say "it's out of warranty, call your local dealer". The problem is that the dealer doesn't seem to know much more than I do (I was the one that actually diagnosed the ATS failure) except they have the service manuals.

    I'd rather not plunk down another thousand dollars on another guess.

    Any ideas on how to trouble-shoot this?




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Scott Alcott

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Its shutting down on over crank, which is a safety to protect the starter.

Posted on Sep 18, 2011

  • Jeff Frontz Sep 18, 2011

    Yes, that's what "OC" means. The question is: what's causing the failure.



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