38 ocean yacht - gen runs but no power!

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Shirley Rice

Member
Joined
May 19, 2021
Messages
10
Vessel Name
Relentless
Vessel Make
38 Ocean Yacht Sport
My husband and I have a 1986 Ocean Yacht Sport with twin Cat diesels.
2# 8D batteries power everything (Currently no house battery).
We purchased this vessel 1 year ago. Boat runs great, generator runs great, all appliances work great but... as soon as we disconnect from shore power we loose anything connecting to 110 power.

We would really appreciate any feedback to help us trouble shoot this. Connection looks good at genset and panel - just can't understand why we suddenly aren't getting power from it.
 
Have you switched the breakers on your 110 panel from shore power to generator? (We are just checking the basics)
 
Sorry if too basic but.... there's probably a transfer switch somewhere.... that tells the panel available power is from the genset versus shore power. It's essentially a selector, sometimes a rotary, sometimes a slide of some sort.

If you've already worked that, I'll retire quietly to the background. :)

-Chris
 
Have you switched the breakers on your 110 panel from shore power to generator? (We are just checking the basics)

Sorry if too basic but.... there's probably a transfer switch somewhere.... that tells the panel available power is from the genset versus shore power. It's essentially a selector, sometimes a rotary, sometimes a slide of some sort.

If you've already worked that, I'll retire quietly to the background. :)

-Chris

Exactly correct.

If the genset powered the vessel during sea trials, then there is a switch of some sort to redirect the AC source from shore to genset.

Otherwise- have the genset output checked.
 
Have you switched the breakers on your 110 panel from shore power to generator? (We are just checking the basics)
Yes. All had been working fine for the past year.
 
Have you done any maintenance on the genny lately? It's super easy to accidently bump and turn off the breaker on the generator itself, especially when changing out the air filter. I'd check that first.
 
Have you done any maintenance on the genny lately? It's super easy to accidently bump and turn off the breaker on the generator itself, especially when changing out the air filter. I'd check that first.
Thank you! That is a good idea to check, it's a 1986 Westerbeke. Will do this today
Jason
 
Thank you! That is a good idea to check, it's a 1986 Westerbeke. Will do this today
Jason


If you have the generator manual, it should tell you the location of the switches and breakers on the generator. Sometime they can be in unexpected locations on the equipment.


Also follow your power leads from the genny to your panel as those can have a fuse or fusible link on them as well.
 
Thank you so much, this is good advice. Jason and I are greatful for your reaching out to us. We will take a closer look.
 
A. check the output switch on the generator.
B. check the main panel for the correct configuration of the lock out breakers for shore power or generator power.
C. If everything is configured properly, call a tech.
 
Another thing that can happen is if the generator was shut down with a load on it you can have the same problem. You may have to " excite" the gen with a 12 volt battery. May should have a qualified tech do it.
Gary
 
Another thing that can happen is if the generator was shut down with a load on it you can have the same problem. You may have to " excite" the gen with a 12 volt battery. May should have a qualified tech do it.
Gary
Thank you Gary. We both appreciate your advice. We will look into this.
Shirley and Jason
 
Any updates? Inquiring minds want to know!

Gary
 
Hello Gary and thank you.
No updates yet. The tec at our marina hasn't located out problem yet. I have an appointment at another marina to take a look at things. This other marina feels confident tjat our problem lies in the control panel. We will so see, I hope. I will post an update when I have one.
Prayers that it will be soon!

Thank you again,
Shirley
 
Thanks for the update and good luck!
Gary
 
Generator runs, no power

You didn't cite the make. Assuming by now you have checked switches as suggested. A generator can be running perfectly when shut down and not produce current when started up again. The most common culprit is the voltage regular which is a board which can be easily detached and sent out to a dealer for checking.
Over the years, I have come to trust Flight Systems. The company specializes in generator controls. FS has a quick 3-day turnaround. I have found them to be totally reputable--returning boards that were not defective.
If it is not the regulator, you should check the bridge rectifier. The procedure will be outlined in a factory service manual. If not have the tech do it.

From there you will have to flash the armature, check the brushes if you have an older unit, or the diodes if it is self-energizing. In the unlikely event should have a shorted stator or rotor it is probably not worth repairing. Depending on the generator you might find someone replacing theirs because it is mechanically worn out. The electronics will be working. I did that once with an older Onan.

Good luck!
 
Thank you so very much Oliver. I just read you message to my husband Jason Rice. You sure did get our attention with your advice and we will look into all you have suggested.

PS: Our generator is a Westerbeke 1986.

Very sincerely,
Shirley Rice
 
My 1991 Westerbeke 5.0BCD exhibited the same symptoms after I overloaded it. It turned out to be a blown capacitor.

https://www.trawlerforum.com/forums/showthread.php?t=41619

We have a 1986 westerbeke 4.4BCD and the same thing happened to us. I measured about 2.5 volts across the rectifier’s ac terminals. I read about the capacitor, and as it was a relatively cheap part I took a chance and ordered and replaced it. It was pretty easy, the hardest part was not dropping the mounting nut into the bowels of the generator when installing the new cap. Fired it up, and we had ac again. The only thing I did wrong was getting the wrong wire on one terminal of the cap so the inverter hated the power. Once I viewed the wiring diagram and fixed the mistake (we had wire #7 and #9 swapped) everything was perfect.
 
Jeff thank you so so much! I will look at the schematics and locate this.

Have a great day Jeff,
Shirley Rice
 
My Westerbeke failed generating shortly after I had the powerhead rebuilt($5,000). I had a Westerbeke rep look at it and he said the powerhead needed to be rebuilt. Sounded lame to me so I got a second opinion. A very old and experienced boat maint expert gave it a look. He found a broken crimp connection! A $0.05 part. It has run well for the last 11 yrs.
 
I lost power to my panel when my capacitor blew. I was told by the prior owner he needed to run a blower when running the generator to keep the capacitor from overheating. Has anyone ever heard this before? I run on diesel so was never running the blower.
 
I lost power to my panel when my capacitor blew. I was told by the prior owner he needed to run a blower when running the generator to keep the capacitor from overheating. Has anyone ever heard this before? I run on diesel so was never running the blower.

I have found that the capacitors in capacitor regulated generators need fairly regular changing IE every 5 years or so.

The first symptom generally is that the generator will not output enough voltage. but sometimes they just go out.

I would just replace the capacitors. It is a inexpensive easy job on most generator ends that use them.
 
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