Knocking in generator

[dirievi]

351DS

[dirievi]

Sorry posted too quickly. Here's what happened. Hot day. Generator running with no issues for about 4 hours with both AC running. Went to bed and all of the sudden no air and hear this knocking and sputtering sound. No power to anything. No circuits tripped. Generator circuits never tripped. I reset everything anyway and only ran rear ac with no further complications. What do you think the knocking was and why would the circuits have not tripped?

[willingtonpaul]

how many hours on the genny ? after the first 50 hrs and then every 150 hrs, the spark arrestor needs to be cleared. buildup there can create back pressure. it is a very simple procedure (look in your manual); just a removal of a plug and then you run the genny for a little to blow out any carbon buildup.

just a thought that there was some back pressure. also could be a plugged fuel filter, or just a hiccup in the engine that caused a voltage drop and scrambled the power flow kicking things off.

also, do you have the ATS ? could be an issue there....

[dirievi]

New rv. Only a few hours on generator. Ran all day the next day with no knocking but was careful to not run both AC since we had other appliances running. I think I overloaded it Friday night but I'm still talking to the dealer about it anyway.

[willingtonpaul]

do you have the automatic transfer switch (ATS) ?

some have had problems with it...with it even being new....

[dirievi]

The rv is a 2015 351DS. I'm not very experienced in features so I'm going to say I believe we have the ATS. Could it be just like the other people who have trouble running 2 AC on a hit day?

[willingtonpaul]

If you have the ATS, it could have very well been the ATS doing the knocking and sputtering not the genset. When the ATS trips, it tries to reset. But with the draw on the genny because the ACs are trying to kick on at the same time as the switch is trying to reset, the switch can't reset. So it keeps trying, and makes a grinding/knocking/buzzing sound. I am willing to bet that is what happened. And my understanding is that once this happens to your ATS, it is never quite the same again; it is prone to keep doing it as it is weakened. I know cause it happened to me, and it seems when the ATS gets hot it becomes prone to tripping out. I have been told that the ATS that forest river uses is a lower end model, and replacing it with a better one is recommended. Still researching that. But take a look at your spec sheet and see if you have the ATS. If you do, I am pretty confident that the ATS kicking out is what you experienced.

[willingtonpaul]

And by the way, was the microwave beeping on and off ? That is the tell tale sign of the ATS trying and failing to reset. A little power makes it to the micro to have it beep, and then it quits....

[dirievi]

That is exactly what happened with the microwave. Thanks so much for all the replies. This forum has been so helpful in diagnosing issues with this rv and the last one we had.