MEP-004A parts, and problems

[joshgar8]

Hey guys,

Where would be a good place to find parts for the MEP-004A. I have one that is having problems with high voltage. I have tested the components within the voltage regulator and cannot find any faults. I do not mind replacing the voltage regulator if need be however the cheapest I have found is $400 plus my core for a take off. I do not even know if that would fix my problem, and hate to spend $400 plus my core to be in the same shape. Do you guys know of any other option? Keep in mind im am by not means an electrition, matter of fact I dont know anything about it other than what the TM's have told me. I have posted my problem on smokstak.com and havent had any replys. I will copy and paste the post here.

Thanks for the help in advance,
Josh



Hey Guys,

I am new to the site and I am in search of some help. I bought me a MEP-004A 15kw 3phase JR Hollingsworth trailer mounted gen set with noise supression.

I got the gen home checked all fluids and filters. After a pre run check up to ensure the years of storage at redstone hasnt damaged anything I fired it up. I got the rpm set for 60hz and the voltage was adjusted perfect. I wanted to let everything get up to temp so I let it set there running for 30 mins or so. I then checked my gauges and the HZ was still 60hz, but the voltage had spiked about 30 volts high on all settings. I was not getting any response out of the micro adjustment with the voltage or hertz. I decided to take the two screws out of the gauge panel to take a look and see if anything abnormal........I find that the reostat for the voltage adjustment is fried, so hot that it melted the porsilen (Spelling?). I went to the local electrical supply place here in nashville and bought a exact replacement and soldered the two wires back on exactly how it was from the factory. I fired it up, and no smoke or anything burned just no response from my adjustments and still a spike in voltage on all settings.

I then get all the repair manuals and start the trouble tree. The military states if the voltage is to high to replace the VR. I took the VR out and proceed to ohm all the components in the VR to try and find the bad component as per the TM. I had no luck finding any problems.

I then decided to take the gen set to HERTZ rental here in nashville to their gen repair shop. The have had it since the second week in january and havent had any luck, however the only thing I know he has done was also check out the VR. He is very busy with rentals and no time for mine. This is what brings me here. After 5 months, I dont seem to think he will ever get it so I am going to attemp to look more into it myself.

Do any of you guys have any opinions on what to do or even a local place here around a couple hrs of nashvile to get this thing fixed?


Thanks in advance for your help guys,
Josh

 

[brianrbull]

Josh, You wont get any Hertz adjustment out of that rheostat. it would have to be one of the precise sets with the hydraulic governor.The HZ on your set is adjusted by the throttle cable. The military used the same control box for both types... I "Think" that the control box is interchangeable between the 004-007 models, as long as you stay in the same HZ range IE 50/60 same.... and 400 HZ same...
As to your voltage rheostat not responding you are 100% sure it is the same part? not doubting you just asking. I will do some reading and get back to you in a bit....

Brian

 

[joshgar8]

Brian,

Thanks for your help. The rheostat that was fried we took down to randolph and rice in nashville and they compared the mfg to the part number on the oem part and came up with the replacement. All the part numbers are correct along with the overall apperience. I am only assuming it is correct based on the info they had in their cross references. I did not check it with a meter to insure its working correctly though. It very well could be a bad part right out of the box but very unlikely. I currently do not have the gen set here, its still at HERTZ but I called the guy today and said I will be picking it up friday at 2:30. I have got to get this thing fixed, hopefully its not to major.

 

[AceHigh]

If you need military surp parts Delk's has everything...

Delk's Army Navy Surplus_Generators

 

[Crash_AF]

Did you check the wiring between the rheostat and VR? If the rheostat burned up, there might have been a short in the wiring that is now an open. Check wires X9H (printed on the wire itself), X82A and B, X80B, and X90A. Should be easy to spot as it will probably be burned up, check anywhere the wiring harness goes through a panel.

Also, test your new rheostat by connecting an ohmmeter across the two outside terminals. The ohmmeter should read 250Ω. Rotate the rheostat completely counterclockwise and check from the center to either outside terminal, it should read 0Ω. As you rotate the shaft, the increase should be smooth from 0Ω to 250Ω

Also, verify that you do not have the Local/Remote Voltage switch in Remote or the Parallel/Local Unit Operation switch in Parallel (both should be DOWN). Both of these can cause the voltage to be unresponsive.

Later,
Joe

 

[joshgar8]

Thanks for all the advice, I am going to pick it up on the way to work tomorrow evening. I will take a look at the things you guys mentioned and post an update of my findings. I hope its something simple.

Thanks,
Josh

 

[joshgar8]

Hey guys,

I picked up my generator set friday on the way to work. Over the weekend I was going to attempt to track the high voltage problem down via the info you all supplied and the TM. I have came to yet another road block. I am not sure what HERTZ did to it, since he wont answer my calls (imagine that) but it will not start. It will spin the engine over fast and all but no fire. Im sure with it being a diesel its a fuel problem. I have started reading the TM about this issue but the second step is to check the engine speed sensor. I tried to reset as per the TM but I cannot verify by the info I have if it was tripped or if I reset it for that matter. Its just alittle push button on the sensor top. I am not sure if its supossed to remain in the down position or in the up position. Currently is is pretty much all the way up and has alittle bit of spring pressure on the button. I tried pushing it back down and then tried starting it but no change.

Also I cannot get any of the lights on the control panel to come on in test mode. no low oil pressure when the engine is in the run position not running. I tested the 1amp fuse and it is good.

Any input on where to start?

To continue with the test as per the tm I have to have a test stand for that engine speed sensor wich I do not have.

Hopefully after we get her up and running again we cant continue on with the gen problem.


oh and yes it does have fuel in the tank, almost full verified with a wooden stick and the fuel switch is in the correct place....

Thanks guys,

Josh

 

[LDMILL]

I am sure it goes without saying you have checked the fuel shutoff valve near the fuel
filler neck.
Have you checked the breaker under the reset button. it may be slightly hard to push in to reset it.
Have you checked for air in the fuel system
Check to see that you have 24 volts to the fuel IP solenoid

Just a few thoughts

 

[PeterD]

Battle short on, run switch on (not start). Do the fuel pumps run?

 

[joshgar8]

I just got the engine running. I checked all the wiring connections at the voltage regulator and exciter. They was not ever screwed down, just somewhat plugged in. After getting all those tight it fired right up.

I still have no lights on the fault light board when oil pressure is low or when I flip the test switch. I took the harness completely off and checked all the wires to make sure they was good and they are. The 1amp fuse is also good.

As far as the voltage problem goes. I still have the problme and I probably wont look into it any further until i get the engine running normally with all the warings lights and such working. I did check the new rheostat that I put in and it ohmed 0-180 ohms. It did not go all the way to 250 like you guys said and lioke it stated it should on the rheostat.


At this point, what direction would you guys go in now to get this thing running just as it would brand new?

Thanks,
Josh

 

[Crash_AF]

You need to get the correct potentiometer first and foremost... that will let your voltage adjust properly.

The disassembly and testing of the fault indicator panel is located in the -34 in section 3-138. You're going to have to pull it apart and troubleshoot why the indicator panel is not functioning properly and make sure it's not missing any internal components.

(ETA: Check to make sure that there are actually bulbs in each socket before removing the box... hate to find out that's the problem after removing it.)

Later,
Joe

 

[joshgar8]

I just got done going over the wiring looking for anything that could be causing my problems. I just looked basically at all the connections to make sure there wasnt anything obviously wrong. I didnt come up with anything other than a bundle of two wires taped together very close to the engine speed sensor. the tape was old and didnt look like it had been messed with at hertz. I opened the bundle of electrical tape to find and connector on the end of each wire, they were both the same connector so there is no way they could have ever been plugged in together. The wire numbers are V64F12 and V65F12. I dont think this could be the problem since it does appear to have been used in the last 20 years but I was just curious as to what it could be? I tried to search the numbers in the TM but didnt find those numbers.

 

[PeterD]

My MEP-004 has the same two wires. Same situation, taped up and appear to never been used. I may take a look in the manual/diagrams and see if I can figure it out, or see if I can trace them one of these days. They are heavier gauge wire...

 

[joshgar8]

Peter,

That is correct, they are about half again as big as all the other wires in the bundle that runs up and over the fuel pump towards the VR and exciter. Now with me knowing yours is also the same way, I know the military did it, not the guy I purchased it from or the guy at hertz.

Where would you start looking for solutions to my other problems? The engine is running and putting out the same high voltage. I do not get any lights when I flip the test switch on the fault indicator. I do not have 24v going to the fuse.

 

[PeterD]

For the lights problem, I think you will have to just tracing out continuity using FO-6 as your reference.

You mention a fuse, which one is it? I'll assume it is the fuse on the indicator panel. OK, check continuity from the DC circuit breaker to the fuse holder's innermost terminal/pin. Try using FO-9 for trouble shooting the circuit. (I'd guess a broken wire at one of the connectors...)

 

[joshgar8]

Yea, I was talking about the fuse thats right below the test switch on the fault indicator panel. I have all the wiring diagrams including the FO-6 and FO-9 blew up and laminated, but as far as reading it, it would do me just as good written in japanese... I am not very good when it comes to reading those things.

 

[Crash_AF]

The mystery wires are on FP3 in the lower left hand side. Look for TH1, which is what is supposed to be connected to those wires. It is a part of the winterization/heater kit for the unit. If the unit didn't have the kit installed, it won't be used.

As far as reading the diagrams, it's like reading a road map. In order to complete your trip, you have to start at a ground and make your way to the battery. Practice extracting some simple circuits on the F03. Then find the same component on the more complicated F01 diagrams and trace it out. If you've laminated them, take a dry erase marker and trace out the path to help keep up with it.

If you were closer, I'd take you to school on it and you'd be able to figure it out in no time...

First thing to do is take a multimeter and test to see if the fault panel is getting any power. Unplug the cannon plug from the back of the indicator panel. Stick your probes in the A and B pin sockets in the plug (If you look real close, the letters are molded into the face). With the DC breaker in and the S2 switch in RUN, do you have 24V displayed?

If so, the problem is in the box, if not, we need to trace back in the harness to find why there isn't 24V to the panel.

If you want to call me to walk you through the troubleshooting, drop me a PM.

Later,
Joe

 

[joshgar8]

Joe,

Thanks for your assistance, its greatly appriciated and very much needed. I just got in from checking terminals "A" and "B" in the wiring harness. I dont not have any voltage at that point. I checked the wiring harness itself for a break in the wires between the big control box and the fault indicator and it checks out good. I also checked that wiring harness for a ground to the generator frame and cannot get one out of that harness. I tried both "A" and "B" directly to ground and still no voltage.

 

[Crash_AF]

Ok, A is the power side of that circuit, so we need to follow that wire back until we get to the problem. It should have power anytime that S2 is in RUN and the CB1 DC breaker is closed.

*ALL TESTS ARE DONE WITH THE CB1 BREAKER CLOSED AND S2 IN RUN*
Find Terminal Board 101, screw 11 (Wire P45J and P45G) and see if there is 24V there.
If not find TB 1, screw 10 (Wire P45D and P45A) and check there
If not, go to the back of S2 (Start/Run/Stop switch) terminal 3 and find wire P45A. See if there is 24V on that terminal when it's in RUN. If not, the switch is bad and is the problem.

You can start at S2 if you want and move through the terminal boards that direction if you find it easier. TB1 will be inside the control panel. Don't remember where 101 is off the top of my head.

Later,
Joe

 

[Crash_AF]

I checked the locations you said to check except for Terminal Board 101 screw 11. I could not find it anywhere on the unit or in the TM. I found station TB1-01 lug no.11 with wire number P45A16, wich that is comming from S-2, BUT i canot physically find that on the unit.

I found S2 wich was simply, the switch wich had 24v on lug 3

I also found Terminal Board 1 that had 24v in lug 10

The only terminal board I could locate only had ten lugs. At first I was thinking that the Terminal Board 101 was the same as TB1 but Terminal Board 1 doesnt have enough lugs. thats the board with 24v on lug 10.

I am going to keep looking for that lug 11, if i find it and it checks out good all three will have 24v.

Josh

Ok, that's a good start. We can eliminate S2 and TB1 from the problem list.

I am working on FO-1 Sheet 4 and 3. 4 has the switch and everything to J1, then it switches to Sheet 3 for P1

On the path of electrical flow, you have J1 which is the large cannon plug on the back of the control panel. P45D (the 16 is just the wire size) runs into this plug on the panel side through Pin R, and comes out of P1 (J is the receptacle and P is the plug) on socket R as P45F.

P45F runs from P1 to P2 pin R, then comes out J2 socket R as P45G. From there it goes to TB101 Screw 11 (Highest number I see on the schematic is 20)
From TB101-11 it branches to J7 (the remote connection plug) on P45H and P6 (the plug that goes into the Fault Box) on P45J.

If you can follow P45J, you should be able to find TB101. I'm going to make an assumption that it is somewhere around or inside the special relay assembly which is where the voltage regulator and other equipment is located... IIRC it's on the right side of the set as you face the control cubicle directly behind the fault panel. You might have to take the cover off of it to keep tracing the wire. The P1 to P2 harness is 2 feet (25 in) long.

Later,
Joe