Generator shuts off and trips breakers

[Rays53hatt]

I have a westerbeke 8.0BTDA. Seems to run great, BUT in the last week it has;
Tripped the 30 amp breaker on the generator.
Tripped the 20 amp red button breaker on the side of the control box.
Both after hours of running under load.

The second time I checked the temp 1 hour after the auto shut down and the temp was 205. I’m not sure if it was at that temp when it shut down, but it was an hour later.

I found very very small leak from the fuel filter, 1 drip every 12 seconds—-fixed by tightening the bowl ring.

Found a slight leak from the back of the heat exchanger. 1 drip every 2 seconds. Prior to starting I added 8 fluid oz of coolant and that filled the coolant tank. No coolant has been sucked in from the coolant reservoir.

It’s been running for 30min under full load, no temp or pressure issues. Stays between 170-185. It runs at 175 for 30 seconds then moves fast enough I can see it move, up to 185, then drops back to 170 in about 10 seconds and stays there for 30 seconds then runs up again.

As I’ve been slowly typing this in to my phone with my thumbs, the up and down cycle has moved up slightly and the low end is now 178 but high end stays at 185

I’m going to replace the heat exchanger, any other ideas?

 

[luna]

Sounds like the thermostat may be slow to react or sticking. Should be a simple, cheap and easy replacement.
I would consider doing this prior to changing the heatx.

 

[Rays53hatt]

Ok, that sounds like a great idea! Even if it isn’t the culprit, its cheap and it will be good to know it’s new.

 

[Mac2]

Check the wires exiting the sound box if you have one. On my previous boat, the wires from the control box, inside the sound box to the external control panel, got chaffed (exiting sound shield) due to the vibrations. This caused the breakers to trip. An easy thing to check before you go nuts replacing parts.

 

[High Wire]

The red 20 amp push button circuit breaker only should trip on overcurrent. Something is wrong in the control circuit. It’s likely that one of the trips is shorting to ground.

 

[fgarriso]

When was the last time you changed the water pump impeller?

 

[Rays53hatt]

Check the wires exiting the sound box if you have one. On my previous boat, the wires from the control box, inside the sound box to the external control panel, got chaffed (exiting sound shield) due to the vibrations. This caused the breakers to trip. An easy thing to check before you go nuts replacing parts.

I will do that first thing in the morning.
Those bolts and nuts for the transfer of power from inside the sound box to outside, were replaced 5 weeks ago, the week before I bought her. Those nuts were loose and I tightened them the first day. I’ll go back and check, I was afraid of over tightening so very possible this is it.

 

[Rays53hatt]

When was the last time you changed the water pump impeller?

Never!! I’ve only owned her for 5 weeks. That is on the “to do” for offense prevent maintenance. But I’m still playing Defence trying to catch up. There is a geyser gushing out the exhaust, so I think I’m ok for the minute.

 

[Sailingveterinarian]

I just had a similar problem with my Northern Lights Generator.
Turned out to be an issue with the built in , push button breaker.
Replaced the breaker. An easy, inexpensive solution.

 

[wrm95]

same problem, same generator. Found supply hose from thru hull collapsed during use, limiting water supply.

 

[Maerin]

Thermostat change out will require dropping the coolant, so will changing the exchanger. You can probably pull the caps of the exchanger to check the seawater side, but IMO that would be getting ahead of yourself. It sounds like your thermostat is functioning OK. There should be a high temp switch for the engine temp as well as an exhaust temp switch, both will shut the engine down. If you have good flow at the exhaust and no steaming, that issue can be lower priority. The breaker issue likely isn't related. I am with the sailing vet; the breakers are cheap and can fail, You could install a jumper with a fuse just under the rating of the breaker in parallel to the breaker, if the breaker trips and the fuse holds, that's pretty conclusive to condemn the breaker. I'd still give a close look at the wiring, and if you have a DC amprobe, check the fuel solenoid for amp draw. The solenoid and the glow plugs are AFAIK the only devices that draw any appreciable amperage.

 

[SteveK]

Engine overheating needs to be solved. A wiring short/breaker tripping is a secondary issue to resolve. Maybe the load is more than it can handle which can lead to overheating. Heat can then trip an old breaker.

I would try running it with no load, start touching the heat exchanger and watching the temp. Look at exhaust for good water flow.

 

[booomer4600]

Would remove the heat exchanger and clean. Many times the capacitor failed and when a motor load starts it pulls 5 time the energy causing the breaker to trip. Capacitors are very cheap. Ten dollars last one I bought.