Overvoltage error on Kohler Generator

[Nheels]

Hi all. I have a 2007/2008 Kohler 5ECD generator on the boat. A month ago or so it was running fine, then shut down giving an over voltage error. I replaced the voltage regulator and fuses, thinking that would fix it..nope. I start it, it runs for about 5 seconds, then shuts down with the OU (over voltage) error. Any suggestions? Thanks.

 

[alldodge]

Unsure but check the voltage that it is high, also check that the Hertz is at 60
If the motor RPM is not correct this could cause the issue

 

[sam am I]

So it appears the design uses a particular dedicated winding off the stator for a feedback(control) voltage to the VR and in-turn, the VR uses this feedback voltage to control rotor current, the amount of rotor current then determines the magnetic field strength of the rotor, which then determines stator's output voltage, whew! It's a closed loop feedback.

Without that feedback, she may run wide open and cause a OV error........ ...........Check those stator feedback connections/wires to the VR and perhaps that winding (resistance and/or output voltage)of the stator.

 

[Nheels]

Unsure but check the voltage that it is high, also check that the Hertz is at 60
If the motor RPM is not correct this could cause the issue

Voltage at the panel pins over 150 after start up, then shuts down. I'm trying to figure out how to determine the Hertz on it, but am having some issues..

 

[alldodge]

Looks like Sam has a great point
With it going to 150V don't really need to figure the Hertz right now

Look for a bad or broken connection

 

[Nheels]

Looks like Sam has a great point
With it going to 150V don't really need to figure the Hertz right now

Look for a bad or broken connection

What would the Hertz indicate anyway? Because it is getting at least 150 does that indicate that Hertz are correct?

I'll check around for loose connections.

 

[alldodge]

Not knowing originally you were seeing 150V was wondering if the 60Hz was higher and it may be causing a over voltage. If Hz was higher this would mean the motor was running at a higher RPM

 

[Nheels]

Not knowing originally you were seeing 150V was wondering if the 60Hz was higher and it may be causing a over voltage. If Hz was higher this would mean the motor was running at a higher RPM

I suppose it could be higher though right as I am seeing the panel pinned at 150 (max I believe). I have such a limited understanding of generators!

 

[Nheels]

Just an update. I replaced the voltage regulator to no avail. I have been directed to the silicone controlled rectifier but the manual doesn't say anything about the SCR for over voltage errors. Any thoughts?

 

[alldodge]

Sam mentioned previously, if there is no feed back to the VR then it can go wild. Need to check the connections going to the VR

 

[Nheels]

Just wanted to report back. Replaced the silicon controlled rectifier and that fixed the issue. The voltage regulator on these units regulates only DC output.