MEP-002 Tripping DC Control Circuit Breaker

[mrcarman]

I ran my MEP-002 for about 15 minutes this afternoon and then it stopped. Prior to that all gauges and systems seemed to be operating fine. I noticed the DC Control Circuit Breaker was tripped. Now when I reset the DC Control Circuit Breaker and I move the control knob from Off to anything other than Preheat, the DC Control Circuit Breaker trips. I've check the TM and this forum for solutions. I found one post related to that breaker being thrown when moving to the Start position but nothing about it being tripped when moving to anything other than Off or Preheat. Any ideas?

 

[Triple Jim]

I'd start by looking for a short in the glow plug circuit, since they're active in positions other than off or prime, but then you said it first tripped while running, so maybe I'm wrong. Maybe clarify what positions trip the breaker, because there are two prime and run positions, the start position, and the preheat position.

 

[mrcarman]

Thanks, Triple Jim. I actually bungled the description of the problem. (I have corrected it.) It should have read that the breaker trips on anything other than Off or Preheat (I said Off and Prime, but that was wrong; it trips on anything other than Off or Preheat). Maybe the fuel pump circuit?

 

[doghead]

I've seen the master control switches fail and cause this, also seen a few capacitors on the fuel pumps cause the same issue.

I'd disconnect the 3 fuel pump wires and see if it trips. if not, plug them in one at a time and see which one(or more) is causing it. You can cut them out and directly feed the pumps without it. They help keep he output "clean". Not needed for our usage.

You did have batteries connected all the time it was running, right?

 

[mrcarman]

Thanks, doghead. That makes sense. I'll toy with the wiring to the fuel pumps for a bit.

You did have batteries connected all the time it was running, right?

Yes, batteries were connected the whole time.

 

[mrcarman]

Doghead, would those make sense in light of it running fine and then it suddenly stopping while running?

 

[doghead]

Possibly

 

[mrcarman]

I am trying to follow Doghead's instructions and have a rookie question: Are both of the connectors in the pictures connectors that can be disconnected? If so, how do they disconnection? Twist, pull? The fuel pump wiring runs through both these "connectors" so it seems like either of these would allow me to disconnect the fuel pumps and hopefully isolate the problem as Doghead suggests. Thanks.

 

[Jimc]

In the first pic there are 3 rubber connectors there. They just pull apart. Disconnect those 3 and you will have taken your pumps offline.

 

[mrcarman]

Thanks, Jimc.

 

[mrcarman]

I've seen the master control switches fail and cause this, also seen a few capacitors on the fuel pumps cause the same issue.

I'd disconnect the 3 fuel pump wires and see if it trips. if not, plug them in one at a time and see which one(or more) is causing it. You can cut them out and directly feed the pumps without it. They help keep he output "clean". Not needed for our usage.

You did have batteries connected all the time it was running, right?

Doghead, that was the problem. Thank you very much for the assistance. I did as you suggested and the first regular pump was the one causing the problem. What is the best way to bypass the capacitor on that pump? I'm assuming just cut the wire in and out of the capacitor and splice them together? Any recommendations on best type of spice to use on that wire to maintain the integrity/waterproofing of the wiring in that area?

 

[Jimc]

Yeah get rid of thise capacitors. If you look at my refurb thread i did a post with pics 2 days ago where i removed mine. To make it easy though you can cut the wire and use a butt/crimp connector and use some heat shrink around the connection.

 

[doghead]

Yes, just cut it out and splice. If you look at Lowe's or Home depot, they should have waterproof wire nuts or butt-splice connectors.

A normal butt-splice and some shrink tube should be sufficient.

Glad you found the issue!

 

[mrcarman]

Sounds good. Thanks, again.

 

[Triple Jim]

If you're ever going to use the generator to power emergency communication equipment, especially HF radios, you'll see why the capacitors were originally installed. As a ham, I cringe just a little when I hear about taking them out. I realize that most of these generators won't be asked to perform around communication equipment, but in a real emergency you never know what will be needed, and diesel engines are inherently nice and quiet to radios, compared to spark ignition engines.

 

[mrcarman]

If you're ever going to use the generator to power emergency communication equipment, especially HF radios, you'll see why the capacitors were originally installed. As a ham, I cringe just a little when I hear about taking them out. I realize that most of these generators won't be asked to perform around communication equipment, but in a real emergency you never know what will be needed, and diesel engines are inherently nice and quiet to radios, compared to spark ignition engines.

Good to know, Triple Jim. I guess if it became relevant, since I have bypassed only one of the three capacitors, if I needed "quiet" operation, I could just disconnect the fuel pump without the capacitor and again have "quiet" operation. Does that sound right?

 

[Triple Jim]

Yes, it sounds right.

 

[Gnoz]

I've seen the master control switches fail and cause this, also seen a few capacitors on the fuel pumps cause the same issue.

I'd disconnect the 3 fuel pump wires and see if it trips. if not, plug them in one at a time and see which one(or more) is causing it. You can cut them out and directly feed the pumps without it. They help keep he output "clean". Not needed for our usage.

You did have batteries connected all the time it was running, right?

Why do I have to flash my generator every time I start it to make it start producing power?

 

[Keith_J]

Flashing the field is usually not required, auto field flash was added due to the 1800 RPM and smallish rotor on the 002 and 003A. There should be enough residual magnetism in the field to bootstrap.

my Lima MAC on the 1031 SECM generated power the first time I ran it, only 1.6 hours on the Hobbs meter since 1989. No electronics, just magnetic amplification. Flashing procedure for that one is frightening.

 

[Gnoz]

But if I do not flash the field pf my MEP 002 for a few second, it will not produce AC output. Do you have an idea what the problem might be.