MEP-003 Hz problem

[AIE1]

So the NorthEaster comes through and I fire up the MEP-003 that has done very well through storms since 2012. Just broke 700 + hours. She was working fine set her to 60hz she takes load fine for a day then all of a sudden I start to see either Hz pegget to the high side after readjusting back to 60 a short time later all the way to the left. It appeared with house loads like furnace (oil burner), well pump, 3 fridge’s and hot water heater didn’t seem to effect the load at all before. Now I’m at a loss, I did the steps in Table 3-3 Troubleshooting #8 I did fine one of the AC output connection slightly loose, however before I could continue to trouble shoot regular power came back on. I will admit I’m no generator man, so I sure could use some good advice.
Thanks in Advance!!

 

[DieselAddict]

Did you check the frequency with a separate meter? Did the engine sound like it was running faster than normal?

The frequency transducers on those units do eventually fail. You need to verify if its lying to you.

 

[DieselBob]

I second the recommendation of verifying with a separate frequency meter. A good quality multi-meter with frequency readout is a very good trouble shooting tool to have available. One of the few failures my 003 has had is the transducer for the frequency meter.

 

[AIE1]

I second the recommendation of verifying with a separate frequency meter. A good quality multi-meter with frequency readout is a very good trouble shooting tool to have available. One of the few failures my 003 has had is the transducer for the frequency meter.

Thanks all for recommendation, I will have to get a little local help on this one, I do have an old TS-352 and don't know if that will work or not. If it turns out to be the transducer for Freq meter are they available at a human beings price? Again thanks!!

 

[AIE1]

I did not check with separate meter! The engine sounded normal however as I adjusted the power control knob to bring the needle back to 60 it would sound like it was below the normal running sound!

 

[jamawieb]

Just get a kill-a-watt meter or buy an aftermarket meter and make a custom holder. The transducers are huge problems and you wont find a new one anywhere. So you'll be buying a used one and no telling how long it will last.

 

[DieselAddict]

That meter as delightful as it is won't read what you need.

An alternate to a VOM meter with frequency is to buy a kill-a-watt plug-in meter. They are pretty cheap on amazon or your favorite electronic retailer. You can plug it into the convenience outlet with a short AC cord. It will give you frequency and voltage. You can also use it around the house to see how much energy your appliance use. All around a good tool to have on hand. Totally worth $20.

The frequency transducer is practically unobtanium. You may find one on fleabay from time to time. You can go with an aftermarket meter and retire the transducer.

 

[AIE1]

Chris, Thank you! I just spent about 45 mins looking through the -24P dated Oct 1983 and I cannot find the Frequency Transducer, am I missing something? Don't know if that is the problem just yet, but was getting a jump start on looking for one if that is the problem. Is the transducer in the meter? The kill-a-watt plug in meter sounds handy definitely will check into one of those. I would like to stick to the original military setup if possible, seems like the more you bastard a piece of equipment the more problems you have. Wife is on me to get rid of "Surplus Junk" (her words)and go with Generac civ stuff. We shall see!

 

[Guyfang]

Look at TM 5-6115-585-24P. Figure 5. Item 46. NSN 6625-01-046-5763. Part number 72-509 or 3128. The TM's will tell you that you must change the meter and transducer. I never did, after the first few times, because the meter will read close enough that it makes no difference.

Open the control panel. To the left of middle, top, is a small box. It has 4 wires. Two on the right and left side. The left side is AC input. The right side goes to the meter. A3 should be printed on the wall, next to the transducer.

 

[justacitizen]

Guyfang
your ability with the TM is astounding. THANK YOU as i keep studying. there is so much info built into a TM that i never saw before.

 

[AIE1]

Look at TM 5-6115-585-24P. Figure 5. Item 46. NSN 6625-01-046-5763. Part number 72-509 or 3128. The TM's will tell you that you must change the meter and transducer. I never did, after the first few times, because the meter will read close enough that it makes no difference.

Use on code A,C for PN# 72-509 and B PN# 3128. Do you know if the PN 3128 for the MEP-112A will also work on the MEP-003A?

I have moved Generator just out side shop, since house power is now restored, beside taking high current draw tools like electric grinders or skill saws to put a load on the MEP-003A any suggestions of what load it up with. I just love trouble shooting an intermittent electric problem!
Again Thanks!!

 

[stugpanzer]

Look at TM 5-6115-585-24P. Figure 5. Item 46. NSN 6625-01-046-5763. Part number 72-509 or 3128. The TM's will tell you that you must change the meter and transducer. I never did, after the first few times, because the meter will read close enough that it makes no difference.

Use on code A,C for PN# 72-509 and B PN# 3128. Do you know if the PN 3128 for the MEP-112A will also work on the MEP-003A?

I have moved Generator just out side shop, since house power is now restored, beside taking high current draw tools like electric grinders or skill saws to put a load on the MEP-003A any suggestions of what load it up with. I just love trouble shooting an intermittent electric problem!
Again Thanks!!

Not sure if you are just loading up the convenience outlet or if you have other means of connecting. I just posted over the weekend about my load bank which is just a breaker panel with space heaters connected.
https://www.steelsoldiers.com/showthread.php?176846-My-Load-Bank

Something like that would work quite well loading the unit up!

 

[Guyfang]

Look at TM 5-6115-585-24P. Figure 5. Item 46. NSN 6625-01-046-5763. Part number 72-509 or 3128. The TM's will tell you that you must change the meter and transducer. I never did, after the first few times, because the meter will read close enough that it makes no difference.

Use on code A,C for PN# 72-509 and B PN# 3128. Do you know if the PN 3128 for the MEP-112A will also work on the MEP-003A?

I have moved Generator just out side shop, since house power is now restored, beside taking high current draw tools like electric grinders or skill saws to put a load on the MEP-003A any suggestions of what load it up with. I just love trouble shooting an intermittent electric problem!
Again Thanks!!

I keep threatening to write a document to help people understand the TM's better. Maybe one day.

ANY TIME, you see something in the UOC, (Usable On Code) block, STOP!! Set the handbrake.

AIE1, whats the difference between the MEP-003A and the MEP-112A? One is 60 hertz, and one is 400 hertz. Big difference. So if the manual makes a destination, between two models, you can bet your bottom dollar, the parts are NOT interchangeable. If there is 4-5 different models, it gets worse. But here, in this instance, NO you can not use it. So what is A,B and C mean?

4. Special Information, located on (PDF reader) page 21 of the -24P manual.

a. (ALL) Identification of the usable on codes are:
Code Used On Serial Numbers

UOC A: MEP-003A EZ00001 thru EZ00118

UOC B: MEP-112A EZ00001 and UP

UOC C: MEP-003A BZ00001 and UP
SERIAL NO RZ80001 THRU RZ80400

Uncoded items are applicable to all models.

You can learn a lot by reading the books.

 

[AIE1]

Thanks, I know use on codes with other vehicles, I only asked because you mentioned both Part numbers. Kind of answered my own question after reading my post. Again thanks!

ran generator for an hour plus today using 120 AC plug in with different tools. Sometimes the 60 HZ NEEDLE would jerk left of 60 at the most to 59. Cannot get it to act like it did under house current.

 

[Guyfang]

Have you checked the linkage yet? If it's loose or sometimes worn, you can get strange engine operation, and engine speed=hertz. If the engine speed is not surging/uneven, the perhaps you have a connection problem between the A3 and S6. I have seen/replaced a lot of A3's and can not ever remember one having an intermedant problem. It works, or not works.

 

[justacitizen]

I keep threatening to write a document to help people understand the TM's better. Maybe one day.

ANY TIME, you see something in the UOC, (Usable On Code) block, STOP!! Set the handbrake.

AIE1, whats the difference between the MEP-003A and the MEP-112A? One is 60 hertz, and one is 400 hertz. Big difference. So if the manual makes a destination, between two models, you can bet your bottom dollar, the parts are NOT interchangeable. If there is 4-5 different models, it gets worse. But here, in this instance, NO you can not use it. So what is A,B and C mean?

4. Special Information, located on (PDF reader) page 21 of the -24P manual.

a. (ALL) Identification of the usable on codes are:
Code Used On Serial Numbers

UOC A: MEP-003A EZ00001 thru EZ00118

UOC B: MEP-112A EZ00001 and UP

UOC C: MEP-003A BZ00001 and UP
SERIAL NO RZ80001 THRU RZ80400

Uncoded items are applicable to all models.

You can learn a lot by reading the books.

Yes Please. write the document.

 

[AIE1]

Have you checked the linkage yet? If it's loose or sometimes worn, you can get strange engine operation, and engine speed=hertz. If the engine speed is not surging/uneven, the perhaps you have a connection problem between the A3 and S6. I have seen/replaced a lot of A3's and can not ever remember one having an intermedant problem. It works, or not works.

Yes Sir, I checked connections between A3 & S6, everything appears tight and check screws for looseness.
Reference the Governor linkage; there is a correlation between the Hz needle moving with the governor linkage. Yesterday after starting Gen set, initially erratic fluctuation of needle. Watching the Hz needle move (left & right) of the 60 hz then watch the gov. linkage there is movement. After warm up less movement, power tools cause the hz needle to fall to 59 then return to 60, sometime with little 60 plus creep. Gen set static running (no load) for an hour, no creep of needle.
SMR code for Governor linkage shows part is DS part, the -12 being an Operator/ Organizational manual does not reference anything beyond para 3-21 (3) about speed control. With that said; my set the govnernor linkage has what I consider a good bit of radial play between the little (lower) and bigger (upper) shaft on the gov linkage. A tap on the linkage while running set of course changes the RPM of engine then returns to what I call sweet spot and continues to run normal. Without having a new or some kind of reference to a Gov linkage inspection, I have no idea what is considered OK or NOT OK.
Back to my initial problem. “Generator under house hold load, then when some appliance like hotwater heater came on at some point the 60 Hz needle would be pegged to right, then adjust the speed controls back to 60 Hz a short time later the Hz needle would be all the way to the left”. It did seem like the running speed was lower then it should be when moving the speed control back to 60. The pig won’t do it while I’m standing there watching, I can stand there for 15-20 mins then walk away come back later and its one way or the other but mainly to the 60+ side.

 

[Guyfang]

Yes Sir, I checked connections between A3 & S6, everything appears tight and check screws for looseness.
Reference the Governor linkage; there is a correlation between the Hz needle moving with the governor linkage. There should be one. Yesterday after starting Gen set, initially erratic fluctuation of needle. Watching the Hz needle move (left & right) of the 60 hz then watch the gov. linkage there is movement. This could be because the engine is not warmed up, or maybe wet stacked. After warm up less movement, power tools cause the hz needle to fall to 59 then return to 60, sometime with little 60 plus creep. Again, this may indicate wet stacking. You also need to expect some moment, when a load is applied. But the set should correct itself, to some extent. Also remember to take the meter readings with a grain of salt. This is NOT a precise power gen set. Take good readings from your load terminals with a multimeter that reads Hertz or a Kill-O-Watt meter. That way you can see accurate readings. Gen set static running (no load) for an hour, no creep of needle. What do you expect? With no load, it should stay in one place. Remember, Hertz = Engine speed. Add a load, the engine will bog a little. If you add a CONSTANT load, the hertz meter drops a bit, and if you leave the CONSTANT load on the set, the engine should stabilize at one speed, (hertz) and stay there. If you run a constant load, you watch till it is stable, then add a touch, to bring it up to 60 hertz. When you drop the load, you need to re-adjust the hertz back down. This is once again, not a precise power gen set. It called a Utility set for that reason. When you have your house hooked up, the load is variable, and your engine will react to the load or lack of it.
SMR code for Governor linkage shows part is DS part, the -12 being an Operator/ Organizational manual does not reference anything beyond para 3-21 (3) about speed control. With that said; my set the governor linkage has what I consider a good bit of radial play between the little (lower) and bigger (upper) shaft on the gov linkage. The linkage should be spring loaded, to move up and down, but only with much force. The universal joints, (ball joints) should allow the linkage to turn a bit. If the U-joints are painted over, the linkage tends to not operate right. CARC paint is a PITA. You should be able to "roll" the linkage right and left with your fingers, but the thing should not flop all over. The screws that attach it should be tight. If the Ball Joints are worn out, the thing will flop around. Easy to see. A tap on the linkage while running set of course changes the RPM of engine then returns to what I call sweet spot and continues to run normal. Without having a new or some kind of reference to a Gov linkage inspection, I have no idea what is considered OK or NOT OK.
Back to my initial problem. “Generator under house hold load, then when some appliance like hotwater heater came on at some point the 60 Hz needle would be pegged to right, then adjust the speed controls back to 60 Hz a short time later the Hz needle would be all the way to the left”. It did seem like the running speed was lower then it should be when moving the speed control back to 60. The pig won’t do it while I’m standing there watching, I can stand there for 15-20 mins then walk away come back later and its one way or the other but mainly to the 60+ side.

I would put the set on a load, say 6 KW and see if it runs right. Do you get Smog plus coming out the exhaust? Or chunks of carbon? If so, leave that baby run for a few hours, then bump it up 2 KW, and let it run some more. Then bump it up again. Go to 100% or a little higher. Make sure you can say its not wet stacked. If that doesn't help, then, have you looked in the -34 manual for the governor cup adjustment? On page, (PDF reader) 7-25 the procedure is listed. Its a bit of a PITA. If the balls in the cup are worn, (and don't forget these sets are probably older then most SS members) the gov will not react properly.

There is also on page, (PDF) 53 a picture of the whole gov-linkage set up. Sometimes the star adjusting nut is maladjusted, or loose. Look at the picture and then compare it to what you have. You can play with it a bit.

 

[Chainbreaker]

...She was working fine set her to 60hz she takes load fine for a day then all of a sudden I start to see either Hz pegget to the high side after readjusting back to 60 a short time later all the way to the left.

What you are describing certainly sounds like a failing transducer (erratic readings, then good, then erratic again). I 3rd the suggestion to buy and use a Kill-A-Watt meter. Once you use a Kill-A-Watt meter you won't care much about a erroneous meter readout on generator panel and replacing it (if you can even find a good working transducer).

The nice thing about a Kill-A-Watt meter is that you can use it when starting the genset to adjust both Hz and Voltage after warm up and then take the meter inside your house and plug it in to an outlet to keep an eye on frequency as well as voltage at further "points of use" while running on generator power. A Kill-A-Watt meter is indeed a VERY handy tool for ~$20.

 

[justacitizen]

i think you need to check your governor droop settings. there is a spring and a set screw under the cooling shroud above the oil filter. the adjustment procedure is in the TM

i think your governor is "HUNTING"