Generator shuts down

[chasmoyer]

This weekend at anchor I started my Kohler 8.5 Kw generator and after 20 seconds I realized I had not opened the thru-hull to cool it. I quickly opened the thru-hull and the water started spitting out as normal. However, after about 4 minutes the genny shut itself down. I vented the heat from the engine compartment and restarted the genny 15 minutes later....it started up just fine, was spitting water overboard, and sounded normal...but again shut itself off after about 4-5 minutes. This genny has 73 hours of use and till now has been a perfect tool. I usually run it 1-2 hours for a.m. or p.m. cooking and battery top-offs.

Did I inflict damage to it during the 20 second running without cooling water....damage the impeller? Any suggestions please.

 

[kloudie1]

Probably damaged the raw water impeller, Chas.. Still pumping some but not enough..I'd open the raw water pump and change the impeller.. but that is just a slghtly educated guess.. Does it give you any error codes ??

 

[Slow Mo^cean]

I wouldn't think a 20 second run without any cooling is enough to do damage. A minute or more, maybe.

 

[Benny17441]

I'm skeptic of coincidences. If the generator was running well before the incident I'll bet that the raw water impeller was damaged and broken pieces may be partially blocking the flow of water. A safety high temperature sensing switch is likely shutting the engine down.

 

[rtmccue]

Temp senser

Check the temp senser on the Exshaust , I overheated the Gen with a Jelly fish clog. The senser shuts down the Generator. The senser was real rusted, but very easy to replace . I would replace the impeller to. I have the same Generator with 500 ? hours

 

[chasmoyer]

Thank you for your suggestions. I have a spare impeller for the genny and will attempt to replace original this week......is the impeller access difficult to get at on this Kohler genny? I clean my raw water filters (engine and genny) after each overnight trip and the genny filter has remained clean...since I didn't get to use it much! Thanks again for your help.

 

[rtmccue]

impeller access

Thank you for your suggestions. I have a spare impeller for the genny and will attempt to replace original this week......is the impeller access difficult to get at on this Kohler genny? I clean my raw water filters (engine and genny) after each overnight trip and the genny filter has remained clean...since I didn't get to use it much! Thanks again for your help.

If you remove the fuel filter and the cooler hose , you can get to the screws. I dont find it as hard as the main engine . Replace the O ring on the cover too. Good luck its a great boat

 

[onecoolair]

my panda will not run more then 20 minutes

Check the temp senser on the Exshaust , I overheated the Gen with a Jelly fish clog. The senser shuts down the Generator. The senser was real rusted, but very easy to replace . I would replace the impeller to. I have the same Generator with 500 ? hours

Were is this temp sensor? I have been trying to solve this same problem for over two years on my 20 minute 6kw kabuda panda. Correction in this Texas heat more like 12 minute panda. Can someone post a picture.

 

[chasmoyer]

Re: impeller access

rtmccue, thank you for the direction. I will try this tomorrow..I changed the zinc today and I take it that the impeller location is just above it on the starboard side of the genny engine? We love the 450 Passage and want to keep her running her best.

 

[chasmoyer]

I appreciate the advice and information re my generator problem. I moved the fuel line and sea water line to the impeller and was able to then get at the four screws holding the cover plate on. Bad news....the impeller was entirely chewed down to the core....no fins left on it. I have started to find some fins in the line from the impeller inlet and some in the next small tank where the zinc is located, but I do not think I can undo the heat exchanger....I may need to get an engine mechanic to do this for me. If you have opened the heat exchanger can you tell me what is involved in doing so? Could I tackle this part of the repair myself or should I get a trained mechanic to do it? My Yanmar engine on this 8 kW genny has only 73 hours on it and I would like it to last a lot longer by doing the repairs correctly.

 

[Rick486]

When something similar happened to my 6kw Panda, I back flushed the raw water system with the dock hose by disconnecting the raw water line at the mixing elbow, and at the raw water pump down stream side. The little bits of impeller came out with the flush water. Worked pretty well for me. Panda actually sells a little gizmo to insert in the raw water system to catch the bits before the heat exchanger if (when) the impeller destroys itself.

 

[onecoolair]

When something similar happened to my 6kw Panda, I back flushed the raw water system with the dock hose by disconnecting the raw water line at the mixing elbow, and at the raw water pump down stream side. The little bits of impeller came out with the flush water. Worked pretty well for me. Panda actually sells a little gizmo to insert in the raw water system to catch the bits before the heat exchanger if (when) the impeller destroys itself.

Ditto on that, I back flush my 20 min 6kw panda the same way from time to time the same way. I have made up a special piece of water hose. I keep handi. And use as a part of regular mantainence, even though I can only get my panda to only run for 10 or 20 minutes for the last few years.

 

[Rob38]

My 4k panda unit in my hunter 38 would only run about 18 minutes. I called Panda and the tech told me there is a wire on relay K3 that keeps the electric fresh water pump running. I found that pushing the relay into the socket actually pushed the spad lug out leaving little contact. I took the relay socket out and reseated all the lugs and insured the reinstalled relay was connected properly. The panda runs fine now.

 

[seadaddler]

Panda Relays

I had the same problem with my 4200 Panda with a bad connection with one of the two relays not making good connection on the relay for the fuel pump and internal water pump .
Once i squezzed the connection for the relay and put the plastic back on she rruns for hours now,viibrations would make it get loose and now no problems.
Nick