MEP-002A Running at 74 hz

[ClarkeF]

I picked up a MEP-002A this summer. Have been working my way through a list of problems: bad fuel (5 years sitting), leaking fuel tank, broken fuel line, general filters and oil change, and no charging when I finally got her running.

Today, I got it running reliably but the Hertz gauge is pegged to the right. I picked up a frequency counter and tested it with line voltage (60hz) and when plugged into the convience outlet on the front of the genny, found 74 Hz up to about 85 hz when I pull the throttle out.

Any suggestions on where to start looking? The throttle control does speed up and slow down the genny - but it must be running too fast still if I can't get the frequency down to 60HZ from 74 at the lowest throttle setting.

The manual hasn't been much help and a quick search here didn't show a match for my symptoms.

Thanks!

Clarke

 

[WillWagner]

Not much experience on mil gen sets, but I have a bit in Onan junk. First see if the RPM is correct. A 4 pole end should run at 1800 RPM and a 2 pole at 3600.

 

[jbk]

check resource section tm5-6115-584-12 pages 7-2, 7-3, 7-4 it covers speed control. the govenor arm, max speed screw or droop rachet could be out of adjustment. also the cable can be adjusted.

 

[coyotegray]

Try adjusting the throttle control. This is what controls the Hz.
Turn left or right to adjust RPM/Hz.
Do not idle it. Idling will cause damage.

 

[ClarkeF]

Thanks for the replies. Had to pull the ASK off to access the governor section (what fun that was). Problem was the throttle cable had lost a strand and was binding up inside the sleeve - not allowing the throttle control to extend enough to drop the RPMs.

In fiddling with it, the cable broke the rest of the way - now I need a replacement throttle cable - any suggestions for a source for NSN 2990-01-046-5864.
Reference Numbers (Part Numbers)

152-0180
152-0180B
345-029-12
345-029-12
72-5091
72-5091

Also it looks like the transducer is on the fritz - tapping on the unit sometimes deactivated the meter. I'll need a replacement for that one too!

Cheers,

Clarke

 

[Isaac-1]

Someone just posted contact information over on the Smokstak board in the military generator section for a guy in Texas that is parting out some MEP-002's (maybe MEP-003's) a couple of days ago. You might also try the usual suspects like Delks or Saturn Surplus.

Ike

 

[jeepin]

If you can't find the original (or can't find it cheap) the throttle is a pretty typical setup for a control cable with locking knob. I found one that worked on McMaster Carr site..

 

[Iyaayas184]

I have a twin set of -002's on a trailer and they both do the same thing. found that by adjusting the throttle down to basically idle the proper output frequency was achieved, however that did not allow for proper rate of charge on the batteries which only seemed to charge correctly when the throttle was at full RPM but then had a 75hz output. Just assumed they were only good for non-frequncy dependent applications like lighting. Will have to domore checking based on what was listed here.

 

[Polycop]

Yikes, 75hz... You are waaay over speeding your generator.

Per the TM the low speed should be set to 1600 rpm with a Hz of 53.3 and a high speed set to 2000 rpm with a Hz of 66.6.

 

[LuckyDog]

check resource section tm5-6115-584-12 pages 7-2, 7-3, 7-4 it covers speed control. the govenor arm, max speed screw or droop rachet could be out of adjustment. also the cable can be adjusted.

I think JBK meant to say the -34.

Thank you JBK for find the pages.

 

[coyotegray]

I have a twin set of -002's on a trailer and they both do the same thing. found that by adjusting the throttle down to basically idle the proper output frequency was achieved, however that did not allow for proper rate of charge on the batteries which only seemed to charge correctly when the throttle was at full RPM but then had a 75hz output. Just assumed they were only good for non-frequncy dependent applications like lighting. Will have to domore checking based on what was listed here.

FYI - Idleing these can damage the voltage regulator.

 

[Speddmon]

I have a twin set of -002's on a trailer and they both do the same thing. found that by adjusting the throttle down to basically idle the proper output frequency was achieved, however that did not allow for proper rate of charge on the batteries which only seemed to charge correctly when the throttle was at full RPM but then had a 75hz output. Just assumed they were only good for non-frequncy dependent applications like lighting. Will have to domore checking based on what was listed here.

Unless you verified that 75 Hz with a good dependable meter other than the one on the machines, I wouldn't believe it. The battery charging alternator should put out plenty of voltage to charge the batteries anywhere above 1600 RPM's...if you are barely getting enough voltage to charge the batts, you might be running it way too slow, and as coyotegray said...that is bad.

 

[Speddmon]

ClarkeF,
Check this link. Not sure if they are long enough, but they provide the function you are looking for.
Throttle/choke cables - Steel Soldiers::Military Vehicles Supersite
BC

Those are nice cables, but they are way too short for the 003a. They might possibly work on the 002a though.