ONAN QD 8K Fault Code 14

[Dwight Lindsey]

My 8K Quiet Diesel shuts off randomly, sometimes after an hour or so, sometimes more quickly.  The fault code is 14, which is "Over Frequency".  I've had the generator out of the coach for a new water pump belt . . . and I'm prepared to take it out again . . .

Anyone know what the fix is for the 14 Over frequency fault code? 

Dwight

[96 EVO]

Well, over frequency usually means it's running too fast.

Don't know which model you have, but, it may have an adjustment. 

[Guest Ray Davis]

Pretty sure an 8k is an inverter gen.   A traditional gen controls frequency by maintaining a constant speed an inverter does it electronically.   I'm not aware of any frequency adjustment but there might be one.

[hex_nut]

My Onan QD8000 is also randomly shutting down after 2 or 3 hours run time in the heat.  I have tried to retrieve the fault codes (blink codes) with no success.  Either no fault code is being set or I am doing things wrong.  I have tried to follow the description for retrieving the codes printed in the manual, but nothing displays.  Can someone give me a quick tutorial on this process?  Thanks

Richard 

[Ivan K]

When your genny quits on its own, the switch indicator should give you the first part of the code, typically 3 blinks that repeat. Hit the bottom of the switch like if priming and you should get the next part of the code, like for instance #6 for the most usual code 36.

[hex_nut]

Thanks Ivan!

However, when my generator quits, the light on my generator is not lit (it is lit when the generator is running).  No light, no blinking, nothing.  I don't seem to be getting any error codes.  Does the light on the dash switch also indicate error codes?  The light on that switch has been burned out for years.  I have just gotten along without it since I could not find a direct replacement for the switch or a way to replace the micro bulb in the switch.

Richard

[96 EVO]

30 minutes ago, hex_nut said:

  Does the light on the dash switch also indicate error codes?  

Yes!

The one time mine had an error, that's where I was reading the code from.

[Ivan K]

Yeah, that is different. All the switches inside and out should show the code. One reason for no code could possibly be that the generator brain loses battery pover and that kills it. Or it is commanded to stop by switch malfunction that just randomly sends a stop signal. Also random moisture connections in the connector on side of the generator. AGS stop setting? I have AGS set to auto start and manual stop for that reason. If the problem is happening regularly, I might disconnect the generator side connector to confirm it isn't commanded to stop from the interior equipment.

[wamcneil]

What happens if you flip the main circuit breaker on the generator and run it with the breaker off?

At one time I had a problem with my generator shutting down and in the course of that I learned that if the generator shuts down without error, it’ll show you the last error that was flagged in the past.  
Onan’s trouble shooting guide led me to try and run the generator with the circuit breaker OFF, indicating that my problem was external to the generator. 
In my case, the inverter was shutting down the generator. 
Do you have a separate AGS or inverter with auto gen start feature?

[hex_nut]

Thank you all for your helpful comments.  It does seem that it is receiving a false shutdown signal.  I had not even considered the AGS.  I will reprogram the AGS and see if it makes any difference.  The difficulty of course is that it is a random happening.  I don't seem to be able to force it to happen.  At times I have let it run for hours in my driveway under load and it has run fine.  At other times, it will run for a couple hours and then shut down.  I will keep your comments in mind and continue to observe its functioning to see if I can determine what is causing the shutdown.

Does anyone know which particular lighted Carling switch was used to control the generator from the dash?

Thanks!  Richard