Generator runs fine but no AC current flow?

[Capt. Rodbone]

It seemed in the first few hundred miles of our Loop trip I was reaching out to this forum almost on a daily basis for thoughts on issues I was having with which I had no experience or knowledge of how to handle. You came through in wonderful fashion. We have been blessed in that we have had many less issues over the last few thousand miles and have about 1500 to go. That has freed up time for me to do proactive things on the boat instead of reactive plus reply in situations where I do have some experience to other forum users asking questions. Like many of you, I feel an obligation to not just be the question asker but help out where I can by contributing. Having said that, however, I am back in a “need for advice category.” Yesterday afternoon, we were running our northern lights generator which we have done quite a bit over the last month. Not my intended topic here, but these new low tolerance ground fault pedestals we had issues with coming through Florida are also very prevalent on the Michigan coast on Lake Michigan. It seems the state of Michigan parks service, whose website many Municipal, and I think even individually owned marinas utilize for their booking services, put out a requirement two years ago, that in order to be a part of their system all pedestals must be replaced by 2024 season end. Being 2/3 through that three-year window most have complied. Since we are still tripping breakers and are going to complete the loop before we invest in the long-term solution, we have used the generator much more recently.

So back to the generator. Yesterday sometime mid afternoon and mid recharging and AC power use time, it stopped generating power. The generator continue to run and starts and runs fine now however I do the breaker on the panel and nothing shows juice. Here are a few questions and thoughts I’ll share.
1. Please confirm I am correct when saying the breaker on my AC panel will either be on or off and there is nothing on the backside of the panel where I can access that breaker I should check or do?
2. Early in our journey, we had multiple situations of the generator not even starting that ultimately were related to loose relay switches. For a period of time I was able to start it by forcing downward pressure on them while also starting the generator by hand below. That worked until we got the shipment of new relays and had them installed. Last night I noticed the breaker switch actually on the generator was very loose. Today I plan to test it with a multimeter in both on and off position. Am I correct in saying the leads should show power coming from that breaker when the switch is on and not when it is off? And if that occurs, does that mean even though the switch box itself is a little loose that is not my issue?
3. I doubt these could be related, but the timing really makes me suspicious and would like thoughts here too. I have a starboard side running light that is an operable. execute the fix I had to at 6 to 200 pounds wedge my way all the way up into Behind the pedestal at the flybridge. I joked that I may fix one wire and damage another handful given I was crawling around and bumping into things. It was during this exercise I believe that the yellow light went off on the main panel. I can’t imagine a reason, however, why wiring from a generator down in the engine room would be going all the way up to anything in the flybridge? Is this likely a correct assumption?
4. Mostly when we were having reoccurring issues related to the relay switches, I had more than one person say you probably should just replace the entire wiring harness. Is there anything about an entire wiring harness that could be causing problems with actual power making its way out from the generator? I’m not even sure what an entire wiring harness encompasses.
5. What else should I be checking?



Sent from my iPad

 

[lwarden]

I would recommend opening the electrical box on the generator and carefully check the input to the breaker. If you have power there then work your way to the AC panel at every connection. If not, it's going to be more serious like a rectifier or issue with the generator coil wiring internally. I had a breaker go out on one leg of power at the generator. Replaced the breaker and all is well. While you are at it, tighten all connectors and terminals and inspect the wire run along the way (with generator off of course).

 

[SteveK]

Look over the generator itself for a overload breaker, could be a push button.

 

[E-Sea Going]

I had a problem with my 16KW MasPower generator (Yanmar Engine with I believe to be a Westerbeke generator). The engine always started and stopped fine but generated no voltage. I called the company's service department, they were very helpful and walked me thru some very simple readings for me to take with my mult-meter, we diagnosed that I had a bad stator. It was replaced and have not had any issues since.

 

[Bacchus]

I had one occurrence where gen ran but lost power output.
It turned out to be simple... one of the fuses on the gen... in my case the outer portion of the holder would not stay in place. I was able to bend the metal tabs that engage the holder w a 1/4 turn.
Yours may be more complex but don't overlook the simple things first.

 

[kchace]

There should be a fuse or a breaker on the generator. Check that too.

Ken

 

[Larry M]

Check all your GFCI’s.

 

[STB]

As for the pedestal RCD breaker tripping, it may not be as much of a project as you think. Shut off all breakers, including the main. Plug in.

If it pops the problem is before the main. Check the shore power cord, especially at the connectors; check the shore power inlet wiring and the wiring where it comes into the main panel; and check any transfer switches (automatic or manual), especially the wiring and connections.

Turn on the main. If it pops, look for and pull the fuses on any back wired loads (gulp). Try again. If it still happens, disconnect any breaker panel loads, no matter how small: LEDs/Lamps, reverse polarity indicators, surge suppressors. Try again. This should isolate it.

Once you can turn on main without it popping, you are home free. Turn on the circuits one at a time to see what causes a pop and what doesn't. Turn each off after verifying it. Leave any chargers or inverters for last. Then, if you have a charge-only device, check it.

Lastly check any inverter. If an inverter pops it, the most likely cause is that the inverted and non-inverted outputs are sharing a common neutral bus. Get another bus bar and separate them. Try again.

Now, start turning on multiple loads at the same time. If there is a problem, the leaks are adding up. When one pops it, leave it off and keep going. When you are done, note which loads you have. Turn them all off. Turn on a leaker. Then turn them back on until it pops again. You found another leader. Do this a few times systematically and you should find your good enough circuits, your really bad circuits, and most of those that leak a little.

Now you are set to plug in at the dock for what is good...isolating devices and wiring on the bad circuits to find and fix them as time allows.

As for the generator, work forward. Start directly at the generator output. If there is nothing there, check fuses and breakers, conventional and push-button, etc, at the generator. If no problem, and able, check the controller back to the generator back end output.

If you do have output at the generator, itself, check forward to any breakers, transfer switches, disconnects, etc. Check for loose wires and bad connections as you go.

Good luck!

 

[High Wire]

1-Plenty of stuff to check other than the breaker itself. If you are lucky the failure will be a loose wire. A bad breaker is also very possible but not as likely. Check for AC voltage at both Line and Load sides of the breaker. If not comfortable, find a dock mate who is. We’re all just guessing here!
Does your boat have transfer switches? Problem could be there too.
2- When you say loose, do you mean it’s physically loose or the toggle action/latching is loose?
3- Doubt very much there is any reason the two are linked. Running lights are DC. Generator output is AC. The circuits are physically separated.
4- people with no clue would tell you to replace the harness! Don’t listen to them. Do you get a full set of dental implants if you have 2 cavities? Of course not. You might have to pay for professional electrical help to diagnose the problem. I don’t want to sound like bragging but it would take me about 15 minutes to zoom in to the issue.
Does the generator itself have power TO the output breaker? If yes, check the Load side. Then check along to the transfer switches then breaker panel.
If No, the generator itself may have a voltage regulator failure.

 

[Old SH-3 Driver]

Greetings, I have a Northern Lights M753 8Kw generator that suddenly failed to produce AC power. The fault was a capacitor (about 2.5 inches tall and 1.5 inches round) in the generator control box. Replaced capacitor and generator has worked flawlessly for over 20 years since. Diagnosis and repair took less than an hour. Hope this helps.
John

 

[Steve1.0]

"So back to the generator. Yesterday sometime mid afternoon and mid recharging and AC power use time, it stopped generating power."

Sounds like the fuse in the control box burned out due to an ongoing (worsening?) fault. I had a NL 783 that burnt a couple fuses on my Morgan ketch. It wasn't grounded properly. Dangerous situation! (fire or electrocution)

As mentioned above, it could also be the voltage regulator board, but something caused it to fail.
As STB wrote, start at the beginning.