12RES kohler starts and run have 105 volt one leg 5plus volt on other leg does not shut down for under voltage .have 13,7 at brushes at slipring

Hi there I had a similar problem years ago. 1) check brushes on the sliprings of the alternator 2) There is a small pcb on the brush gear and an electrolytic capacitor some diodes etc. check for bad joints or capacitor 3) lift off one brush from sliprings and connect for a couple of seconds a 12 volt battery to it. Why? The rotor must have some residual magnetism for it to develop excitation and sometimes if the genny was not used at all for a long time then that magnetism sometimes die away. It also happen if the genny was disassembled for one reason or another Good luck

No you cannot, a 60HZ unit is designed to run (and the controller expects to see 60HZ) RPMS 1800 for a 4 pole rotor and 3600RPM for a 2 pole. Slowing engine speed down to 1500RPM the controlelr would see it as under frequency

No it is not typical, you never indicated if you are measuring it under load or not. Repeat that test under 1/4 load and see if they even out.

If it has a couple hundred hours or more, try cleaning the slips rings on the back of the rotor shaft. They should be very shiny and not black or polished looking.

Check that when you run it, it is not in fact making correct voltage (within about 10% is good), also make sure the engine is coming up to full speed, 3600 or 1800. You could check this with a multimeter that measure hertz. On the main output leads when the genset is running make sure it is getting close to 60 hz. or if you are in an area that uses 50 hz. check for that respectively. There are a couple things that would affect this, one would be your SCR module. There is a test procedure for this which you could find here. http://www.scribd.com/doc/50171916/tp6196-1 . I don't work on marine units, mostly standby so these manuals are for residential. Check your fuses, could even go as far as checking the wiring in the back and wiring and condition of the brushes and sliprings. These actually build field voltage to make 240 or 120 volts whatever your unit is configured to make. The brushes need to sit flat on the slip rings and on a unit with 10 hrs. the sliprings I can't imagine would be very dirty but check that as well. If you have an ADC2100 controller use this manual to go into the controller to verify that it is set for the correct voltage that the machine is built to make. The only other fairly simple thing to check that I've had issues with is if Kohler mounted a fuse block on the side of the cabinet mounted to the genset with no vibration isolation. Check these fuses while attempting to run the unit and make sure you getting steady voltage out of them as sometimes they will vibrate causing pulsed voltage to come out of them and can give you an intermittent UU, UF, or OC fault (undervoltage, underfrequency, overcrank).

Is there a fault?? All UL listed generators including Kohler are required to lockout on a fault on shut down. This really sounds like a problem with your 2-wire auto start connection between your automatic transfer switch and genset. RDT model automatic transfer switch it is the 2 middle wires on the green connector and terminals 3&4 in the generator. close to run and open to shut down. Any open at any time will cause the unit to shut down. The 12 will shut down instantly upon an open because your 5 minute cool down is built into the transfer switch.

You have to reset it because it locked out on on under frequency. Just pullout the fuse on the control panel and then reinstall it a couple of seconds later. Now it will reset the fault codes. Hope that helps.

Sounds like a short in one of the windings to me. Can you verify that the engine rpm is not exceeding specs? If you can modify the engine speed Id say slow it down and see what the voltage read is.

check connections on speedsensor or take down rpms must be a screw or bolt on de fuelpump

call koler but ui think is meant high heat as in the thermal circut is shuting you down or low oil
could be a couple of things best bet call kohler