Westerbeke 15kw diesel gen stalling

"Okay then I jumped the two wires together and the gen ran normally although I haven't run it very long. What does this tell me?"

It reads like you found the problem.

If you want more confirmation, put your ohm meter across the terminals of the temperature switch and see if it goes open at a low or normal temperature. If it does then that is the problem.

The second oil switch may be an "auxiliary" oil pressure switch that has a use other than the safety circuit.

I think the second or one of the two oil switches is a safety that does not allow the starter to engage if someone hits the button and the engine is running.

Skipper

If I have read this thread correctly, your genny is now running fine? If so, you may have had a momentary block to your water supply that fell away before the restart.

What do you think would reach an overtemp condition first if the raw water supply was blocked?

A) The engine jacket water.

B) The raw water cooled exhaust.

It would be nice to get some feedback from the OP, wouldn't it?

Would someone please check to make sure he didn't get electrocuted poking around on his now apparently functioning generator.

C) the raw water pump and it's impellor, then B, then A.

A, B or C

You should have stopped at C !

The water sensor is most likely going bad. In the pic it looks like the terminal on the right is loose or not connected the way it should be to the sensor. After the gen is running move/jiggle the wires/terminals on it and see if it shutsdown...... Either way, They're cheap, just change it.

The two oil sensors. The normally closed one is most likely the oil shutdown sensor. The normally open one, closes once there is oil pressure, is most likely a safety that will not allow the start button to work once the generator is running (or vise-versa), so that someone doesn't inadvertantly break the starter by keeping the start button held down after it has started.

Not all Westerbekes have the exhaust sensor. Some do, some do not. Yours probably does not if you cannot find it. It will be on the exhaust riser that your rubber exhaust hose is connected to. Within 12" of the exhaust hose, if it is indeed equipped with one.

Considering there was no C, I agree. There was no C because there is not a safety switch on the raw water pump.

That's because only you can answer that question. You have to check to see if the switch opens at a temperature lower than intended.

You are the guy at the scene with the test equipment, we are just sitting at our computers asking questions and making suggestions. The rest is up to you.

The newer Onan gensets also have a sensor for water flow (the computerized ones) and if they don't detect waterflow just past the impellor within something like 7 seconds, they'll shutdown for that also. But that's a different generator than the OP's, however still valid to your question. hehehe

I would just change it, they're pretty cheap, take 2 minutes to change.

If you really really want to test it. The best way or most accurate way would be to remove it, get a pan with water in it, put a submersible thermometer in the pan, turn the burner on high, and put test leads on it connected to a multimeter, put the sensor end in the cold water, stand there until the water boils or the switch closes and watch the ohm's on your multimeter until the thing closes......note the temperature on the thermometer.......

Also you should run the generator fully loaded and see what the water temp is getting up to. Because at a 1000 hours, the heat exchanger should be cleaned. Water flow through it may be fine under light to moderate loads, but it's possible that your water temp is creeping up under heavy loads, such as when underway when you have all a/c's cranking, just turned the water heater on, etc. etc....

CskipR

Just curious, how did your genny run today?

Skipper

I had a problem with a roaming oil pressure. I pinched the connector a bit with a needle nose to make the leads to the oil sender tighter and that solved my problem. If you think a loose wire is the problem, try that?

You ran for 6.5 hours back on 4/3 with no problem, then it shut down after 4 today. Have you run it in between? Also, did it just shut or did it sputter or surge out before shutting? Also, were you running when it shut or standing still? An intermitant problem often indicates a short or lose connection.