Westerbeke diesel 5kw problem

[ancora]

The gen set starts right up but only runs about one minute before shutting down. Before shutting down the RPMs drop off. Put jumpers on all the two NC shut down alarms, i.e., exhaust, water temp. and pulled the leads on the NO oil pressure alarm. Replaced the K2 run relay, and the fuel shut-off solenoid, to no avail. Removed mixing elbow..all clear. There is exhaust water flow. The engine mounted 20 amp breaker trips every time the engine shuts down. With only 410 hours on the unit I am perplexed on what to do next.

 

[High Wire]

The breaker tripped is the key. It should never trip unless there is a control circuit short(overcurrent). Something is shorting to ground. Instead of jumping the switches, disconnect both leads of the switch one switch at a time. The NC switch leads will need to be jumped.

 

[luna]

The 20 Amp breaker that trips, what is it providing power to?

 

[SIBERNUT]

Question is , what happens first? Leave breaker tripped & start up, same thing happen?

 

[twistedtree]

Check what the actual current is through the breaker. It might not be over-current, and just be a bad breaker. If it is over-current, then meter each of the loads served by the breaker to see which is drawing too much current.

 

[porman]

Is the breaker a round push in/pop out type? A friends' Westerbeke was doing the same thing and it was a bad breaker.

 

[Pete Meisinger]

If you are losing power it sounds like a fuel problem. The tripped breaker may be secondary.

pete

 

[TowLou]

If you are losing power it sounds like a fuel problem. The tripped breaker may be secondary.

pete

Thats my thought. Tripping secondary as a shunt trip after shutdown like cats like to do.

Find out why it is shutting down. Now if it sounds like its taking a load then shutting down thats a different end of it.

Is it putting a load out when it does shut down?

 

[twistedtree]

The breaker will only trip from over current, or begin defective, and when it trips the engine will shut down.


I can't think of any way that a fuel issue would cause the breaker to trip, so would definitely address the breaker first since it is a clear problem, explains the shutdowns, and has to be fixed regardless.

 

[Barking Sands]

I was just poking through some diagrams. I believe if its the 20 amp breaker of the typical westerbeke mounted back by the glow plug solenoid that breaker powers the glow plugs, starter circuit, but also the fuel lift pump. If the fuel lift pump is malfunctioning it could trip the breaker. Giving you all the symptoms you describe. When you hold down the preheat does the clicker pump sound normal? They are pretty cheap and easy to change.

 

[Barking Sands]

Is it this arrangement?

 

[richchiles]

Check for corrosion in the wiring harness connections, my Westerbeke did the same thing and that was the culprit.

 

[Bob328]

I had a start solenoid short to it's case and trip the breaker. Removed the solenoid and isolated it from the mount. It ran fine, so I replaced the start solenoid and has worked fine since. The vibration caused the problem. To diagnose, I did a voltage check from the solenoid case to the engine block and showed voltage. The solenoid has to be away from the engine mount. To get home, I put the solenoid in a sandwich bag and hung it with a zip tie. Worked fine until I was able to get the replacement. It was the Westerbeke 8kw model. Hope you find the issue.

 

[ancora]

We finally got it running. Removed the connections to the engine mounted breaker, installed a jumper with an inline breaker and it ran until we shut it down. Took a while, but the satisfaction of seeing it through is priceless.

 

[High Wire]

Thanks for closing the loop.