MEP003 CB2 DC control breaker

[bchauvette]

Just got the MEP003 that came with the M1061 trailer/laundry unit AKA Kermit hauler running. Looks like it was completely serviced and never run. Fresh oil, air and oil filters etc.

The DC control breaker pops after several minutes of running. The battery charge meter is in the yellow. Oil pressure is around 40 PSI. I am pouring over the TM's and posts and it sure would help if any of you genny gurus have any suggestions.

At what point do I worry that the cooling air flow slats aren't opening? Hint I do have an IR heat measure gun.

Does a fault like low oil pressure or over temp pop the breaker?

 

[Triple Jim]

At what point do I worry that the cooling air flow slats aren't opening? Hint I do have an IR heat measure gun.

There's a procedure to test them in the TM. It takes a long time, a hot day, and a big load to make them open very far.

Does a fault like low oil pressure or over temp pop the breaker?

No, they just stop the engine. Something is drawing too much 24 VDC current, or the breaker is bad. I guess you could put an ammeter in series with the breaker and see just how much current is passing through, and go from there.

 

[Isaac-1]

On the topic of the slats, be aware they operate by a cylinder of expanding wax, so do not try to disassemble and clean it out.

 

[lxawolf]

When you say your battery indicator is in the yellow, are you saying yellow as in displaying below 24vdc? If this is the case it could be a weak or worn out breaker. Esp if it was pulled and pushed out a lot during its previous life. I see them online not sure of the exact specifications but they should have a part number you can find on it or in the TM.

 

[dangier]

You could have a fuel pump capacitor going bad. I cut them out, crimp the wire back together with a butt splice, and heat shrink the connection. Not needed in 99.9% of the applications. Pull the wire braid back to do the above. Capacitor is located in the power wire about 6 inches from each fuel pump and should be bolted with the fuel pump bolts.
David

 

[LuckyDog]

You could have a fuel pump capacitor going bad....
David

That was my first thought.

 

[dangier]

I also would not put much stock in the original battery charge (condition) meter. I have seen them all over the place. Put a good multimeter on the batteries while running. You should have 27.5 to 28.5 or thereabouts.

 

[bchauvette]

Mep003 control breaker update

Mep003 update

Here is an update to my CB2 DC control beaker popping. The Genset needs to run between 5 to 45 minutes before it pops. So I have to wait that amount of time for every test iteration. Thank God and Coffey1for my Fluke meter. It has a max hold feature where I don’t have to watch the amp meter for 5 to 45 minutes while the set runs waiting for the breaker to pop. I wish had another meter to monitor the breaker current. My Chinese meter won’t allow enough current through to slap the starter solenoid. I’m worried the breaker is going to wear out with all this testing.


Here are the findings so far;
1) There is in fact an overload across DC Control CB2. Beyond the 10 amp range.
2) It is not the fuel pumps. Disconnected the caps any way.
3) It is not the DC line from VR2, Battery charging. Disconnected the Cap any way.
4) It is not the DC bridge A4


It appears the breaker feeds TB4 and TB5 then the voltage branches out from those. I physically checked continuity to each of the 28 terminals. I am in the process of checking current through each of those connections. Keep in mind the meter needs to be hooked up in series meaning the terminal block connection has to be undone and it needs to run up to 45 minutes for the breaker to pop to get a reading. So far consumed half a tank of fuel.

Going to individually check the governor shut off solenoid, oil pressure switch and the over temp switch.

Did find a chafed wire on a high voltage wire that wraps around the "Tap Transformer" no signs of arcing.

I believe the reason they let the generator go is they gave up diagnosing the problem. I am having a blast. I retired from doing this so I would have more time doing this

What does those pointing fingers mean on the schematic? Are they the latest ECO's ?

 

[Isaac-1]

I am glad you are enjoying this, do let us know what you find, all this talk of connecting the meter in series makes me glad I invested in a DC clamp meter a few years ago (Fluke 337a).

Ike

 

[bchauvette]

I am glad you are enjoying this, do let us know what you find, all this talk of connecting the meter in series makes me glad I invested in a DC clamp meter a few years ago (Fluke 337a).

Ike

DC Clamp!!!!! boy do I feel old. Bet they've been around for a while.

 

[bchauvette]

Update.....

I'll start at the end it is the Governor/Fuel/Shut Off solonoid. An internal short increasing as temperature increases. It took over 3/4 tank of fuel and 4 days on and off, mostly on testing. Not being able to get the master switch removed from the panel to get to the lugs to test went to testing the individual wires connected to TB4 & TB5. That was a bad decision. There are a possible 36 iterations to test. Having to wait for a fail for every test and that fail taking from 5 min to 3 hours proved to be impracticable. So went back to SW1 and I added a second meter to CB2 so I didn't have to wait for the beaker to pop. Monitor for the beginning of the end before popping the breaker shortening the test time. My Brother printer came with PDF software that allows printing a page across six 8-1/2 X 11 sheets. A blessing for the schematic .

The folk on Ebay are very proud of their Governor Solenoids $400.00. If I can't find a reasonably priced one going to fabricate a manual shut off. Note my posting in the "Parts Wanted" thread.

B.T.W. The TM's use different names for the same thing throughout the documentation!! Making a PDF CNTRL F search ineffective. The name for something in the TM and find it in the part TM with the Find function may not work.

 

[dangier]

Success! Something to keep on file for future issues. Many thanks for following through.
David

 

[bchauvette]

Just took the solenoid apart. O.M.G. If there was any doubt that was the problem they are completely erased.

It is a very interesting configuration. The are two inter-wound coils. To pull the plunger both coils are used. To maintain hold one coil is dropped out by a set of contacts released by the plunger. The contacts are completely burnt, The varnishing is cooked, bare coil wires. Thing stinks!!!

I developed a highly sophisticated complex temporary stop device. A paint stir stick

 

[Triple Jim]

Good work finding a painfully intermittent problem. A lot of solenoids, including many/most starter solenoids, have two coils like that.