Mep 002A Battery Indicator

[RWG421]

I fired up my first Mep and it runs great, I ran it for about 5 hours an noticed the battery indicator stays in the same spot (Border of Green yellow)
The voltage at the battery terminals: Stopped 25.7 / Running 26.1
So I assume its charging, but is that enough voltage.

I know my civi trucks voltmeter is pegged when the battery is discharged; dose this work the same way?

I noticed some "brown snot" that at some point in time ran from around the Frequency transducer. Is this some double secret military sealant or is this transducer on its way out?

I assume the Frequency transducer does not affect battery voltage, but I’m a little confused because it says AC in - DC out on it.

 

[doghead]

They have a very low output charging system. They do not charge like an automobile.

 

[Isaac-1]

It sounds like you have a charging system problem, either in the DC voltage regulator or the alternator itself, my guess is the DC regulator. It looks like it is putting out some voltage, enough to keep it running, but not enough to charge the battery fully. If the parts to fix it right are too expensive and if you have power where you store your generator, you could opt for a 24V battery charger to keep the battery topped off.

Ike

p.s. the transducer reads AC and outputs a DC signal to the meter on the front panel.

 

[jbk]

this gauge reads the battery voltage not altenator output. i just put a new regulator on mine (overcharging) i have new walmart batts. and my gauge is in the same position as yours. i had 27.2 volts after 40 min. of run time. i think yours is fine.

 

[Keith_J]

The "alternator" is unlike any other military vehicle in that it is a permanent magnet rotor, much like a motorcycle's charging system. IIRC, 7.5 amperes maximum. As the voltage approaches 28, the current is shunted to a resistor. Like a motorcycle, the regulator dumps a good bit of this excess power as heat. This is why it is under the blower shroud.

The DC battery charging has nothing to do with the frequency meter. The frequency gauge is a simple current meter, the transducer converts the frequency to a proportional current, causing the needle to move. Yes, your transducer is leaking. It may be dying a slow death. I would recommend an inexpensive tachometer from a radio control hobby shop and put two reflective patches (Scotchlite) 180 degrees apart on the blower, using a strong light to trigger the tach. 1800 RPM there is 60 Hz on the AC.

You could also try a diesel tachometer, these install a sensor on a fuel line. Again, 60 Hz is 1800 RPM on this generator as it has a pair of pole pairs (called 4 pole generator, older gasoline generators had two poles and ran at 3600 RPM).

 

[Isaac-1]

On the frequency meter topic, if your looking for functional cheap replacement, Hardy Diesel sells a digital LED volts/hertz meter on ebay for about $20 (they do not advertise it on their regular web page). I have one, it seems to work fairly good, except the LED display is a bit dim in direct sunlight.

Ike

 

[Keith_J]

On the frequency meter topic, if your looking for functional cheap replacement, Hardy Diesel sells a digital LED volts/hertz meter on ebay for about $20 (they do not advertise it on their regular web page). I have one, it seems to work fairly good, except the LED display is a bit dim in direct sunlight.

Ike

That is attractive. Now if it is digital with decent resolution (1/4 Hz), it would be fantastic.

 

[RWG421]

Keith_J ,

So the battery gauge read out and volts I stated = A normal functioning DC charging system.

So with the dying frequency meter, as it goes will it give inaccurate reading? Or will it just die

Will running low/high frequency hurt anythings down stream.

Are there original replacement available? or are they to much $$

Thanks for your help,

 

[Harleyd315]

Home depot has a small hand held volt/hertz digital meter for $39.00 thats what I use. My frequency meter on my 02 bounces around a bit, so I depend on the hand held unit.

 

[Keith_J]

Keith_J ,

So the battery gauge read out and volts I stated = A normal functioning DC charging system.

So with the dying frequency meter, as it goes will it give inaccurate reading? Or will it just die

Will running low/high frequency hurt anythings down stream.

Are there original replacement available? or are they to much $$

Thanks for your help,

Yes, the battery/charging indicator is indicating correctly. It is a DoD standard item which works well enough.

Running the generator outside of 1800 RPM will generate power with frequency outside of 60 Hz, this can damage motors, transformers and the like. Better to run it slower as many motors/transformers are capable of running on 50 Hz for Europe power.

Replacing the transducer might be expensive. Being simple connections, tag and remove the wires, then pull the unit to see where it is leaking and attempt to plug the leak.

Simpson Electric made these. Good luck finding one as it was a special item. Simpson makes a direct-reading gauge for frequency that has 3% accuracy. You see the reason for this transducer-gauge pair? 3% is the rated range of total frequency variation. If the gauge is only accurate to 3%...like measuring the thickness of a single sheet of paper with a yardstick.


EDIT: I may have located a new transducer. Just need to know the current range of the output, either 0-1 or 4-20 milliamp.

 

[coyote62ny]

try tom at gulf coast trucks he has used parts for these sets and reasonable prices office 1-281-422-3200 cell 1-832-323-1445 and you can also try delks surplus at 1-336-629-0991 i got a transducer from them and i think i paid 50.00 for it but that was over a year ago as for the battery gauge mine has a new regulator on it and mine runs at the upper edge of the green and if you check the voltage across the batteries it runs 28.5 volts i got the regulator from southern automotive they make them for the military and that is what the tech at the co. told me i should have at the batteries hope this helps you get it going

 

[RWG421]

Just got back in from picking up a M105A2 at Nellis. I will check on the range tomorrow,

Thanks

 

[Speddmon]

Running the generator outside of 1800 RPM will generate power with frequency outside of 60 Hz, this can damage motors, transformers and the like. Better to run it slower as many motors/transformers are capable of running on 50 Hz for Europe power.

Just a word of caution about what you suggested. While the statement is technically correct, most motors are designed to run at 50 Hz, your generator is not. The MEP series generators were designed to run at 60 Hz. Running the engine slow enough to only produce 50 Hz can and more than likely will over tax the voltage regulator and fry it.

 

[RWG421]

Keith_J
This is the tag I pulled off the leaking Frequency Transducer, Is this the info you need to see if you have a match?
Thanks for helping on this I would like to keep it original if possible and financially practical

 

[Keith_J]

Keith_J
This is the tag I pulled off the leaking Frequency Transducer, Is this the info you need to see if you have a match?
Thanks for helping on this I would like to keep it original if possible and financially practical

That is a different one than what I have seen. Of course it could have identical output as the ones made by Technology Research Corporation of Clearwater FL. In any case, clean it up and try to locate the leak and fix it. My best guess is the fluid is just dielectric oil. Since this device doesn't consume much power nor delivers but a tiny bit of power, heat generation is nil.

How to fix? If around a connection, act like a dentist and remove the case material around the connection until the plastic is sound. Do this with the leak oriented high to stop the leak, keeping it free of oil. Then fill the cavity with RTV silicone. Permatex Ultra Black will work. Let cure 24 hours before moving the repair lower than the body.

Remember, we are direct support AND depot maintenance. Just because the TM and/or part are listed not serviceable doesn't mean we cannot fix what is broken. I have fixed the ammeter and fuel gauge on my 002A. And even welded the rusty fuel tank (TM lists soldering as repair method, I have TIG skills).

I've just finished applying POR to the stripped generator body. After a week of phosphoric acid pickling. And using POR fuel tank sealer on the tank to prevent future corrosion. Now to find gaskets for the filters and batteries that aren't $100 EACH