Mep 002a trips DC breaker

[dlbard]

I was wondering if someone could give me some help on where to start fixing my gen set. My generator was running fine when a loose battery terminal disconnected. The generator immediately shut down and now won't start. When I go to start it, it will run in the auxiliary pump setting. Thent when I go to the main pump , the dc breaker trips immediately. Any help would be appreciated.

 

[Ray70]

Try unplugging the main pumps 1 at a time. If you find that one of the pumps is causing the problem try cutting out the noise suppressor in the wire. ( volted to the pump mounting bolt.
If that doesn't fix it then the pump itself may have an internal short.

 

[rickf]

"Bolted to the pump mounting bolt"

Thought I would add that in since we are talking about an electrical part and that was confusing.

 

[Ray70]

"Bolted to the pump mounting bolt"

Thought I would add that in since we are talking about an electrical part and that was confusing.

Oops! correct! "Bolted".... I was typing and drinking my 1st. coffee first thing this morning..

 

[rickf]

I am wondering if when the cable came off the regulator spiked the system with high voltage. That happens in vehicles and usually takes out the alternator but I have seen blown lights and computers from old time mechanics pulling off a cable to see if it still runs. Proves the generator is working" they will tell you. Well, they were right back in the days of DC generators. This is why you always tighten the cables.

 

[Guyfang]

OK, lets start simple. You should have three E-pumps. Two provide fuel to the engine when the S2 is in the normal run position AND in the Aux position. One is for Aux fuel function. But all three are supposed to work in Aux position.

My generator was running fine when a loose battery terminal disconnected. The generator immediately shut down and now won't start.

Now this gen set was designed to run WITHOUT batteries. So it should have continued to run, on the DC output of the 24 Alternator. Tell us, did it stop as soon as the cable fell off? Or did it run a while? Or do you know? don't guess, know. If you are not sure, tell us.

Like Ray wrote, disconnect the E-Pumps, one at a time to find the pump that might be bad. Why might be? If the set runs in Aux mode, all three pumps SHOULD be running. If it runs in Aux, and not the normal run mode, that's kinda strange. Let first see if there is a bad pump. I would disconnect ALL three pumps, and try and start the set and make it run first in Aux, and then the normal rune modes. If the set runs in both modes, plug them one at a time into the Aux pump wire. If the first one pops the CB1, continue to test the other pumps also. Just to be sure.

 

[dlbard]

Thank you for reply. I'm away from home right now, but I will try that and post the the outcome. Thanks again!

 

[dlbard]

It shut down the second the cable came off. I knocked it off.

I didn't see any sparks

 

[Guyfang]

If the set stopped as soon as the cable came off, that makes me think your battery charging system is not working.

Is this set new to you? Have you had it a while? Has it run for longer periods before this happened?

 

[Ray70]

I was wondering if someone could give me some help on where to start fixing my gen set. My generator was running fine when a loose battery terminal disconnected. The generator immediately shut down and now won't start. When I go to start it, it will run in the auxiliary pump setting. Thent when I go to the main pump , the dc breaker trips immediately. Any help would be appreciated.

For clarification, the breaker is tripping when you switch to Prime / Run but before you attempt to crank at all?

 

[Ray70]

If you are not cranking the engine, I don't see anything that would be powered in Prime /Run that is not also powered in Aux. ( as Guy pointed out ) however, I wonder if you could have shorted out diode CR-3 when the wire came off somehow, and if current is flowing backwards perhaps it's overloading the DC breaker??
Just a thought.
Should be easy enough to verify if CR-3 is good or not.

 

[dlbard]

Ok. Got home and did as was suggested. The first pump I disconnected, the one closest to the operators panel, was unplugged and it fired right up. I let it run about a half hour then shut it down 3 times and it restarted every time no problems.
You guys are awesome! Thanks!
Only thing not working now is the Frequency gauge.

 

[Ray70]

Now try cutting out the noise suppressor on that pump and try with it plugged in and see if it works correctly.
For the frequency meter, 80% of the time the transducer is bad.
Best solution if transducer is bad is to either ditch it and get a direct reading Hz. meter ( analog or digital )
Or there were TRC transducers on ebay not long ago that were from a newer model machine, but the work just the same, all you need to do is slightly alter the bolt pattern holding the transducer to the rear wall. I just looked and don't see them but maybe try looking around.

 

[Ray70]

Found 1 of the TRC transducers on Ebay.
https://www.ebay.com/itm/355610147163 If you need it.
This is by far the cheapest way to replace a failed transducer other than using a plastic Chinese direct read gage.

 

[Ray70]

Just beware this one is located in South Korea apparently! says total shipping is $29 including import fees......

 

[Ray70]

Scratch the above auction link.
Here's a domestic auction with cheaper shipping and 10 available!

Frequency Transducer 60 HZ 13211E6901 P/N 10380 | eBay

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