mep 831a what is this?

[chrisross]

What is the thing at the top left in the aluminum looking box to the left of the muffler, with the red cover? The manual says Frequency Converter. Mine is missing. Does anyone have one to sell?

Also while i'm here, if you need a fuel filter with the nylon bowl, this is less than $20: https://www.amazon.com/gp/product/B07GQMLRBM/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8

 

[Guyfang]

Good luck. Like hens teeth. BUT, will say, one time I was looking at gov auctions, and saw a large cardboard box, with lots of parts in it. At least two of the parts were a Freq Converter. So there are some out there. But very hard to find. That's why your set has none.

 

[69birdman]

View attachment 817430

What is the thing at the top left in the aluminum looking box to the left of the muffler, with the red cover? The manual says Frequency Converter. Mine is missing. Does anyone have one to sell?

Also while i'm here, if you need a fuel filter with the nylon bowl, this is less than $20: https://www.amazon.com/gp/product/B07GQMLRBM/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8

TRC's website shows they may have some new and rebuilt. I think I priced one from them years ago when watching some 831s missing inverters, VERY pricey !

 

[chrisross]

https://www.logsa.army.mil/psmag/archives/PS2003/605/605-45.pdf

 

[chrisross]

crap. what is the output without the inverter?

 

[Guyfang]

Zero. Maybe you need to read the TM. No inverter, no generator. Just a paperweight that has a nice motor.

 

[Dieselmeister]

Keep looking on GovPlanet. They just sold three in the last two month. Don't know if they worked, but it would be a start. Search for TRC 29350. I have also seen them on E-pay.

 

[chrisross]

Is TRC 30554 the same thing?

Well I'm finding "Designed to meet requirements of TA 30554-98-831" so that's probably why I see TRC PMG 30554

 

[Guyfang]

I am not sure what TRC 29350 is. TRC is the company that makes parts. Normally electrical parts. 29350 COULD be a part number. It could also be a CAGEC. That is a code to represent the manufacturer. Every company that supply's to the military has a CAGEC code.

CAGEC The Commercial and Government Entity Code (CAGEC) is a 5-digit numeric code which is used to identify the manufacturer, distributor, or Government agency/activity that supplies the item.

TRC 30554. Well, we know what TRC is. So, 30554. Its a CAGEC code, for the MEP. Mobile Electric Power organization. A military organization that is responsible for Mobile Power Generation. They also supply parts to the military. See above explanation.


Well I'm finding "Designed to meet requirements of TA 30554-98-831" so that's probably why I see TRC PMG 30554

Wrong. 30554, or better know as MEP, controls MOBILE ELECTRIC POWER. Period. The come up with requirements. They set the limits. They decide who get the contract. Any on, and on.

30554= MEP.
98= year project started.
831= What type Gen set.
"Designed to meet requirements of TA 30554-98-831" = That the part is designed to meet the requirements set down by MEP, to fit and work in the MEP-831A gen set.

What you really want to know?

 

[chrisross]

Thank you for breaking down the terminology. I am finding auctions that call the Inverter / Frequency Converter "TRC 30554" and also "TRC 29350" which is TRC's actual part # for this piece. I was wondering if they are indeed the same item and they appear to be. Now I better understand where the names come from.

 

[kloppk]

29350 is TRC's part number for their 60 Hz Inverter.
Here is a shot of an 831's data plate with all the numbers on it.
(One of 3 dead inverters on my bench...)

 

[Guyfang]

293500, (TRC part#)= NSN: 5895-01-477-0855
98-19604-01, (MEP part#)= NSN: 5895-01-744-0855

5895-01-587-6582 is the PRIME NSN. The first choice, of the two. Several years ago, the -0855 NSN was replaced by the -6582

 

[ECS]

The company that makes them still does but they are $2500 each. They will call you back but they never seem to answer the phone.

I see used ones for sale sometimes, from people parting them out.

 

[m35a22ton]

The company that makes them still does but they are $2500 each. They will call you back but they never seem to answer the phone.

I see used ones for sale sometimes, from people parting them out.

Sounds like it is time for a parts generator, find one with a bad motor!

 

[Ray70]

Unfortunately you were not alone with regards to missing your inverter. There were dozens of 813's rolling through Chambersburg PA about a year or 2 ago. Almost all of them were like brand new with only 2 hours showing on the meters.
People freaked out and paid top dollar for them, not realizing the most important piece was missing.
But.... that's how the auction game goes. it's always Buyer beware!
Not sure why the inverters were all removed, but I suspect there was probably some kind of govt. regulation in play that required these to be "disabled" at some point, for some reason. Someone on here probably knows why, but that's my hunch.
Good luck in your hunt, probably best to find a parts machine as M35a22Ton suggested!

 

[m35a22ton]

Unfortunately you were not alone with regards to missing your inverter. There were dozens of 813's rolling through Chambersburg PA about a year or 2 ago. Almost all of them were like brand new with only 2 hours showing on the meters.
People freaked out and paid top dollar for them, not realizing the most important piece was missing.
But.... that's how the auction game goes. it's always Buyer beware!
Not sure why the inverters were all removed, but I suspect there was probably some kind of govt. regulation in play that required these to be "disabled" at some point, for some reason. Someone on here probably knows why, but that's my hunch.
Good luck in your hunt, probably best to find a parts machine as M35a22Ton suggested!

I just ordered / purchased another gen from iron planet and verified in pic that the inverter was in unit! I was worried for a second!
On a side not love the first unit I have,

 

[kloppk]

Inverters can occasionally be had off of ebay. A buddy of mine picked one up a couple of weeks ago. I tested it for him and it worked perfect.

You have another option if you strike out finding an inverter. That's to remove the PMA and install a conventional generator head on the engine.
I've done a couple of these swaps and can recommend a US source for gen heads that fit. I also have a Governor Controller available that maintains 60 Hz after doing the swap.

 

[Guyfang]

Unfortunately you were not alone with regards to missing your inverter. There were dozens of 813's rolling through Chambersburg PA about a year or 2 ago. Almost all of them were like brand new with only 2 hours showing on the meters.
People freaked out and paid top dollar for them, not realizing the most important piece was missing.
But.... that's how the auction game goes. it's always Buyer beware!
Not sure why the inverters were all removed, but I suspect there was probably some kind of govt. regulation in play that required these to be "disabled" at some point, for some reason. Someone on here probably knows why, but that's my hunch.
Good luck in your hunt, probably best to find a parts machine as M35a22Ton suggested!

I just had to ask someone in CECOM about the missing Inverters. He told me there was a shortage of them. The gen sets were at the end of their life cycle, (going to be replaced with something newer) and no new or rebuilt inverters were to be bought. The gen sets exceed the MEL, (Maintenance Expenditure Limit) due to age and availability of inverters, so a bright person changed the SMR code, (Source, Maintenance, and Recoverability Codes). This code tells you what you can and can NOT order. The codes were changed from PA, ( Item procured and stocked for anticipated or known usage) to XB, (Item is not procured or stocked. If not available through salvage, requisition.) A requisition for an inverter would be forwarded to an Item Manager. The Item manager decided if the requisition would be filled. A so called "Fill or Kill" requisition. If the Item manager did not consider the request to be of major importance, (Units down range, or Units that had a very high priority) the request was killed and the unit was told to turn in the gen set. From there it went to the "Bone Yard, (DRMO) or the Cannibalization Yard. So when the Army got word that this gen set was being washed out of the system, Someone decided that before the gen sets were sent to the Bone Yard, the Inverters would be stripped out of them, for use in generators that met the criteria for "Mission Essential" criteria. So expect to see lots of these gen sets being sold missing inverters, or, with inverters that are Non-Op.

 

[dav5]

Inverters can occasionally be had off of ebay. A buddy of mine picked one up a couple of weeks ago. I tested it for him and it worked perfect.

You have another option if you strike out finding an inverter. That's to remove the PMA and install a conventional generator head on the engine.
I've done a couple of these swaps and can recommend a US source for gen heads that fit. I also have a Governor Controller available that maintains 60 Hz after doing the swap.

Kurt, is the governor controller the same as the one that you developed to replace the SLC100 controller?

 

[kloppk]

Kurt, is the governor controller the same as the one that you developed to replace the SLC100 controller?

It's not the same. The one for supporting a conventional gen head swap has a number of other functions besides the task of governing engine speed.

The SLC100 replacement varies the engine speed based on load applied so that the inverter is supplied with adequate power from the PMA. As I recall the RPM range is from 3,050 RPM and no load to 3,450 RPM at full load.

The version for the "head swap" is designed to maintain the engine speed at a constant 3,600 RPM regardless of load applied. This is necessary so that the conventional gen head maintains 60 Hz and correct output voltage. Besides the engine speed governing it also monitors the current load on both L1 and L2 of the gen head, drives the %Load meter and provides overload protection to open the contactor should either leg of the heads output be overloaded. The governor controller is more complex as well as having a pair of current sensors that get put on the gen heads output leads.
With the inverter removed the contactor control is lost, overload protection is gone and the Load Meter ceases operating.
The controller restores those functions.