While running my Westerbeke 7.2BCGTC...

[Face89]

While running my Westerbeke 7.2BCGTC on my 2000 380DA under a typical full load (both A/Cs, TV, Stereo, air pump briefly), the microwave was used and suddenly something blew or tripped, and the boat lost all 120V power.  

The genset continued to run that day, and still fires up and runs fine now…except no 120V genset power to the boat.  Shore power works normally though.

I can’t imagine that kind of load would be enough to damage the unit.  Rather, I would have expected a breaker to trip on the Sea Ray panel if too many amps were being drawn.  But what do I know?  I did check the main breaker on the genset located near the front-left corner and it is not tripped.

Any guess as to what likely happened or advice as to where I should continue looking for the problem source?

Thank you

[wingless]

Welcome to the forum.

The generator has a dual pole breaker at the generator.

There is also a pair of 120VAC breakers in the salon, part of the shore power / generator interlock system.

Check all the breakers. Cycle off then on if tripped.

[Face89]

I believe the dual pole breaker you’re referring to is the only 120V breaker on the generator (left front outside corner if standing between the generator and starboard engine). While that breaker seems odd in that it moves very easily between on and off, I don’t think that’s the problem. Im not getting any measurable voltage before or after the breaker…people smarter than me are saying the stator/windings have gone bad.

If true, Unfortunately Westerbeke has discontinued production on replacement backends. So now im looking at a rebuild…trying to figure out cost/effort involved in pulling out the generator’s electrical box and giving it to someone who can bring it back to life.

Briefly contemplated buying a whole new gas EFI genset (nearly $20k parts/labor), but R&R looks like a nightmare. Besides, the gas portion still runs great.

[wingless]

Swapping a dead 7.0 BCGB backend on the 380DA is not the most horrible job. The boat has sufficient access for that task.

Why is yours identified as 7.2 BCGTC? Has this already been swapped?

Depending on the location, the local marine generator shop could / should already have a rebuilt backend available to swap for the dead unit. It should / will also already have fresh electrical parts, like capacitors and the like.

A good first step is to perform the manufacturer's electrical measurements from the manual that confirm this is required.

If backend replacement is required, my suggestion is to detach / leave the engine and only yank the backend.

Do a super complete inspection / service / clean up / repaint of the engine during this repair, especially of the hidden back side. Here is the fuel pump / cooler on mine that I cleaned up / repainted. I also swapped those two skinny bent fuel pipes w/ new OEM parts. I swapped the fuel pump w/ a visually identical part / not OEM that has been working fine for a decade.

https://live.staticflickr.com/65535/51425410197_b14b787c9d_c.jpg

[Face89]

This is the placard on the genset, 7.2BCGTC, which is consistent with the owners manual. I was not the original owner for the first 7 years, but I have no evidence in my documentation suggesting a replacement.

[Face89]

I am having someone do more thorough electrical testing this week per the technical manual. But if that fails, I’ll be looking to have a shop rebuild it, or better yet, buy a rebuilt unit off their shelf as you suggest. Here in Chicago with our short seasons however, I don’t think we have the luxury of such specialization to find a marine generator shop. But i will search.

[wingless]

How about contacting a company in the "Boating Capital of the World" like these people (zero affiliation) to see if they can provide timely assistance?

https://browardarmature.com/

[wingless]

Note, it might be required to remove the engine riser and elbow, plus the fore / aft aluminum H channel floor support to attain sufficient physical clearance for the backend swap.

For my 2000 380DA I always maintain an inventory of exhaust gaskets. It is very handy to permit the required annual disassembly for corrosion inspection of the internal raw water passages.

[wingless]

As an example, the tree spark plugs are on the back wall.

During the backend swap, removing / replacing w/ properly gapped spark plugs is a good idea.

Cleaning / painting that back side of the engine (if required) is a good idea.

Note that in addition to removal of the exhaust and floor support, the cockpit bench above that floor is "easy" to remove by yanking a couple of clevis pins.

[Juanca]

Hi @Paul Adreani, I had similar problems with a Westerbeke 7.2, and a 5.0 bcg. Two things:

(1)There is a breaker switch in the back lower part of the generator (really uncomfortable place.) If you find that breaker switch, just flip it back up. This should return the unit to normal operation the next time to start it.

(2) If the generator was overloaded (maybe the microwave,) then you might have lost a capacitor. The capacitors are located on the top of the unit (looks like an electrical box.) Open the box by unscrewing the four screws on top. You will see the two capacitors. Inspect for burn marks anything weird. The generator needs the both capacitors in order to product a full 120.

(Make sure all power is turned off when opening the electrical components.)

[Face89]

Thank you. I was only aware of the breaker on the lower left side towards the front. Perhaps the orientation on yours was different, making access more difficult? Assuming you’re saying there are two, I will look for another one.