I have a Mep 004A that has a overload light on. The set is putting out correct voltage to the overload relay input side, but of course no voltage at output side. If I battle short the set before start up the relay functions as it should, however the set has no power to start on battle short. I tried looking at the TM, but I dont really know where to start. I had a lightning strike on a tree close to the unit a few months ago and have not used it since then. The control box behind the control panel is leaking sticky varnish looking fluid as well. All guages seem to function as they should and output is as it should be at the guages. Any Ideas or direction would be greatly appriciated.
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mep 004a help
- Thread starter charger53
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Please take a picture of the "control box behind the control panel" is could be the Frequency Transducer, but with this kind of symptom, is most likely the Thermal Watt Converter.
Sorry, should have been more specific, it is the thermal watt converter. The freqeuncy transducer look fine from the outside. If you believe this is the source of the problem, do you know where I can get a replacement? I am very mechanically adept, however generator function is all new to me....
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Do you know what a UOC is? Usable on code? If not, let me know.
Try and look at the test procedure for the Thermal Watt Converter. It's in the -34 manual. Unless you have a rather nice electrical workshop, you need to find a friend who does. Its not hard, but you need a crap load of gear that most people just don't have.
Try and look at the test procedure for the Thermal Watt Converter. It's in the -34 manual. Unless you have a rather nice electrical workshop, you need to find a friend who does. Its not hard, but you need a crap load of gear that most people just don't have.
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I dont no what a UOC is, and there are no electrical shops within 100 miles. I am a car guy and have a good multi meter and thats about it. Usually the best bet for me when it comes to complex electrical is to replace the part with a known good unit, in this case looks like that would set me back about 100.00. Please let me know if there is a better way.
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The watt converters always seem to leak. Does not mean it's bad. They are potted with a black substance that is sticky right out of the box. I opened a new one up.
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First the UOC. Did you notice in the -24P manual, that the thermal watt converter, (TWC from now on) is listed twice? Look at the manual. Item 31 I think is the TWC. Listed twice, different part number and NSN. So what's the right part for your set? In the first few pages of the TM, there is an explanation of terms and a "how to use this manual". Towards the end is the explanation of the UOC. In it, it lists all the model numbers for the different gen sets. And there are several. You have a MEP-004A. Look to the right and you see CLD. That is the UOC. Now look at the two listed TWC's, and notice that to the right of the NSN's, are the UOC. Pick the NSN with tour UOC. Some people assume, and that will get you in trouble every time, but they assume that the 60 hertz (MEP-004A) parts are always listed first. It ain't so. Learn what your UOC is, and always look for it. 99.99 % of the parts fit all models. But it's that .01 that will mess you up.
Now, to the testing of the TWC. If you looked at the procedure. Can't do it with your multimeter. And you can't do the test for the M4, (watt meter itself) because you can't close the output circuit breaker. So we need to get that to close first. You said in your first post that if you use the battle short, you can get the overload relay to function right, but " the set has no power to start". By that you mean the gen set will not turn over and start? That's normal. Try first starting the set, flip the battle short up, and then push the output circuit breaker to the closed position.
Now, to the testing of the TWC. If you looked at the procedure. Can't do it with your multimeter. And you can't do the test for the M4, (watt meter itself) because you can't close the output circuit breaker. So we need to get that to close first. You said in your first post that if you use the battle short, you can get the overload relay to function right, but " the set has no power to start". By that you mean the gen set will not turn over and start? That's normal. Try first starting the set, flip the battle short up, and then push the output circuit breaker to the closed position.
I have tried that as well, ouput circuit breaker will not close with the close switch even if the battle short is up when the set is running. It will only close if the set is in battle short and not running. I will verifiy this again tonight when I get home, but I did try that. The set is putting out rated voltage on the incoming side of the breaker, however nothing on the output side including battle short and attempting to close breaker. If I leave the set not running and battle short it I can close the breaker and it has continuity to both sides.
Thanks again for all the help. This set has saved our skins in the winter and I would like it to be reliable again.
Thanks again for all the help. This set has saved our skins in the winter and I would like it to be reliable again.
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The only safety relay not bypassed by the S7, (Battle short switch) is K13, (short circuit relay) and the S11, (Over speed switch). If you connect a wire between pins 5&6 on K13, then start the set. Flip the S3, (AC contactor switch) up, to try to close CB2, (AC contactor) normally. If it won't close, then turn on the S7. Then try and close the CB2.
Your set IS in the single set position? That's S6.
Your set IS in the single set position? That's S6.
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Yes, set is in single position, I will bypass k13 and give that a try tonight if the weather permits. Thanks for all your help again. I am terrible at military style manuals, they just dont fit well with my brain. The help you have provided would have taken me weeks to figure out and I would have to print the entire manual and study it in printed form to get anything useful.
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Well, you know, that's why I begged, stole and conned my way into a copy of every TM, for every generator set in the army, while working as a contractor. Sadly, I gave them all back when I stopped.
upon further investigation I have discovered that the breaker will close when the set is in battle short mode. Turns out I wasnt holding the breaker switch long enough..... So the set operates as it should in battle short mode putting out correct voltage. I still do not have a understanding as to what triggers the Overload condition, I do understand that if overload is detected it will trigger, but not what in the set measures that condition or activates it.
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Open up TM 9-6115-464-34.
Go to page, (PDF reader ) 44. It shows you Troubleshooting for: MAIN LOAD CONTACTOR FAILS TO CLOSE. Go to step 6.
Step 6.Defective overload reload relay K14. Check relay K14. Replace if defective (para. 3-89).
Paragraph 3-89. TACTICAL RELAY ASSEMBLY. This passage shows how to test the Overload relay, but unless you have a real nice electric test set up/shop, I don't think you can do it. You could take the relay to someone who has the right test equipment, and they can use the procedure listed here to perform the test.
What I would do if I was you, is find a Tactical relay box to borrow, and see if the set works. Then perhaps you can buy one.
There is an Overload relay in that big auction house for $45.00. Type in 5945-00-318-3050.
No, this is NOT the NSN in the -24P manual. That number has been superseded by the 3050 NSN.
Go to page, (PDF reader ) 44. It shows you Troubleshooting for: MAIN LOAD CONTACTOR FAILS TO CLOSE. Go to step 6.
Step 6.Defective overload reload relay K14. Check relay K14. Replace if defective (para. 3-89).
Paragraph 3-89. TACTICAL RELAY ASSEMBLY. This passage shows how to test the Overload relay, but unless you have a real nice electric test set up/shop, I don't think you can do it. You could take the relay to someone who has the right test equipment, and they can use the procedure listed here to perform the test.
What I would do if I was you, is find a Tactical relay box to borrow, and see if the set works. Then perhaps you can buy one.
There is an Overload relay in that big auction house for $45.00. Type in 5945-00-318-3050.
No, this is NOT the NSN in the -24P manual. That number has been superseded by the 3050 NSN.
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Glad it works. Take care