intermittent genset issue

[carolinacoast]

Our #2 gen is a kubota/phasor 12.5kw V1505-EBG Generator is Lima Electric 250 gold medallion12 lead 240 volt single phase; which runs fine for 2-4 hours, and then the 220 and 120 volt service flickers with a constant load-no breakers blow, and then the engine stumbles as it reloads. the 220 comes back on, the 110 also TV, lights ..everything. The dropout is maybe 1 second. I assumed it was an engine/fuel flow issue and have chased that to the point I believe it is not. Also, the #1 20kw onan pulls from the same fuel line and there is no issue like this. Is this just an electrical issue on the #2...windings..exciter...How to I find this intermittent issue. The issue repeats itself every 3-6 hours after that over a 3 day period. Thanks in a advance.

 

[Angela]

Acknowledging that you said you've chased the fuel flow and not found it to be an issue, I'll share with you my "genny gremlin" story. For about a year, I scratched my head over why my 2-year-old salon/galley AC units would not run properly only when on genny power, on an intermittent basis which I could not replicate for any technician (had both the genny tech and the AC tech out...nobody could figure out the problem) - the air handlers slowed to almost no air flow, and the whole air handler sounded like rocks rolling in the dryer, but only every now and then (and never on shore power; only on genny power, and never when a tech was here). No other problems whatsoever on genny power, not even with the 30-year-old AC units, anywhere. At the suggestion of a few HOF members, I eventually changed the fuel filters (both primary and secondary) and like magic...problem solved for the galley/salon AC units. Those are controlled by digital controls with an electronic circuit board which is, apparently, VERY sensitive to even the slightest fluctuation in voltage. So, to make a long story short....when chasing your problem and ruling our fuel flow, did you change both filters? If not, try it and see if your gremlins go away.

Now, it is my newer AC units that tell me when to change the genny's fuel filters, rather than the genny or any of her gauges.

 

[bobk]

I had a very similar issue as Angela. I'll add that you should check the system for air leaks into the fuel. In my case it was one of the seals on a Racor filter housing.

Bobk

 

[carolinacoast]

Seals in the Racor..... I do cut corners on that and do not change all of those...just a visual check.. For clarity it is not just my Air Con that cuts out it is TV, LIghts, air cons refrig, everything. Is the thought that the larger gen just pulls more fuel and is less sensitive to the issue than the small one? I used a new mechanic for the oil change and maybe the the small filter on the gen was not changed. good thoughts. thanks. I will stick with fuel issues.

 

[Angela]

For purposes of comparison in terms of whether the larger gensets are less sensitive, I have the 15KW Westerbeke; don't know whether that's larger or smaller in someone else's eyes, but I wouldn't call it small, and it is more sensitive than I would have thought. My experience has been that changing that little filter on the genset was the critical point for my problem. I change it less often than I do the Racor because it's not quite as easy to do, but when no one could pinpoint my problem, including me, I changed that little filter and that seems to have cured the problem. Well, it has run perfectly ever since, anyway. Apparently, it doesn't take much to mess it up. The little filter looked fine when I took it out, but I popped a new one in there anyway and was back in business. It hasn't stumbled, not once, since.

 

[bobk]

Mine is 12.5 KW Westerbeke. I use a 2 micron Racor and only change the small engine mounted filter every second Racor change. (Not to start the micron war again)

Bobk

 

[carolinacoast]

I also use a 2 micron racor, and the engine mounted spin on for the #2 is a 2 also. I will change that one and report back. In theory it should be fine, but the consensus is a fuel issue. Thank you.

 

[carolinacoast]

Thanks Angela and Bobk.....you were both correct and spot on as a Brit might say. My big 2 micron was clean BUT the 2 micron on the gen (which was supposed to have been recently replaced-same guy that tried to,put delo 400 in my mains- already fired).

Purrs like a happy genset.....thanks so,much. Thanks SAMs for providing this valuable communication.

 

[Canuck Dennis]

what's wrong with delo 400 in the mains ??

 

[doc g]

should be using delo 100 in the 2 stroke Detroits.........Pat

 

[Pascal]

what's wrong with delo 400 in the mains ??

A few years ago Delo 400 was re formulated and is no longer approved on DDs. Delo 100 should be used

You d be surprised how many mechanics still uses it though!