Advantage or Disavantage of re-wired 400hz generator to 60hz?

USAMilRet

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if you made a deal for a fully functional machine that's what you should get,or a refund,or any other deal that you and the seller can be happy with and in that order. "just my opinion no offense". now as far as repair if you decide to keep it then this is the place to ask and source for parts. also there are some good folks here who rebuild and resell good working machines also. and if it helps all i can offer right now is it sounds like the value of the machine is not much above salvage and that is only because of the risk involved. it very well could be a decent machine but the risk of significant cost is great.
A full refund has been on the table since the beginning on this.
 

justacitizen

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as far as price. i purchasheed an 802A with about 5000 hours from a craigslist ad a few month ago. i paid 700 dollars delivered to my residence. the unit runs fine and makes good power but it also has a few cosmetic issues and some other problems i need to address before it is ready for an extended outage. when i am done i will probably have about 1200 dollars in it. like i said it is fully functional now but just needs some freshning up. with current prices and availability there are also commercial gen sets like Kubota,Lister etc to consider.
 

98G

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Right....where these gensets that are not working, wont crank, have parts missing, and are mostly salvage, sell for over $5K not counting the processing fee and time and trouble for pick up. Yes, I have seen some great deals happen when reading the forum but as a general rule, expecially due to the hurricane season last year and the still demand for gensets in PR, you will be lucky to find a fully functional Harbor Freight scream machine for twice that amount.

A little more realistic price would be more helpful than <$500, from a 98J to a 98G.

https://www.govplanet.com/for-sale/...sm|0,k|mep803a,mf|1&rr=0.5&hitprm=&pnLink=yes
I bought a 20kw machine with single digits on the hour meter on a trailer for far less than the 803s are bringing right now. Clean enough to eat off of...

Market value outside of hurricane hysteria is around $3k for a fully functional MEP803 with 500ish hours.

Hurricane hysteria is driving prices, combined with tax season buyers. If you're buying at full retail, you want a fully functional cosmetically perfect machine turn key ready.

If you're rolling the dice on a fixer, roll the dice all the way and buy a nonrunner at auction. You seem capable of doing the fixes yourself and pocketing the equity.

If I'm paying $5k, it's going to be a civvy diesel welder/generator that I can sell after hurricane season for what I have in it.

Of course my situation isn't yours. My genset use is offgrid rural AZ property, not sudden storm failure of necessary power. I'm also looking at this from a "can I sell it for more than I have in it" standpoint.

For $9k I'll deliver the one pictured to your driveway- 20kW of 120/208v, 120,000btu of heating, and 10ton AC. Turn key ready, and quieter by far than an MEP803. I don't seriously think you'll take this offer, as I consider that to be full retail price. I just throw it out as a point of comparison.

98J, the joys of piranha jammers.....

20180527_113539.jpg
 

USAMilRet

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Well, that gives me some idea. I can have this one for a little over $3K with 202 hours on the generator an 5 hours on the rebuilt engine, but with the issues mentioned. I still think that this is going to be an minor fix. For a low hour generator with a newly rebuilt engine, it is hard to pass up. It runs and it runs well until put under heavy load. This indicates to me a minor mechanical issue that has not been discovered. With everything else that is coming with it (fully dressed), I think that I will not find a better deal. Granted, you are in the middle of the US but here in FL, with the hurricane hysteria, a freaking crank radio is going for $1K which is $900 overpriced. Yeah, I did not start the hysteria, but unfortunately, I have to live with the effects.

For the last 9 months, I have been looking for another 803 sourced from multiple places and everything is $5K to $7K more that what this is going to cost me, and there is no guarantee that the units will even run or produce electricity. As far as other generators, I have been looking at/for them for 3 years now and I am still back to where I am right now. Gensets are worth more right now than some houses.

I am limited to a 7KW to 10KW unit. A 40KW unit will never see more than 10KW used and that will kill it faster than a bullet to the head.
 

justacitizen

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yea it sucks to be in a panicked market but that is what it is. get a new air filter and set the valves and adjust the timing on each fuel pump. get one of those laser type temp gauges or even better a thermal camera to see if you have a cool cylinder. make sure the primary fuel pressure is up to spec and load it up and let the rings set. it might get better on it't own. i read on another forum from a member who was working on a Caterpillar D315 with intermittent engine problems hard starting and low power. he was ready to pull the fuel system apart to get a rebuild when by chance he found a rag in the intake manifold and under a valve. have seen many farmers rebuild the turbo on their tractors because of a dirty inner air filter.
 
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zarathustra

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Hmmm. The unit that only generates 7Kw... What are the symptoms when you load it further... does the engine quit running, or does something trip up.
And just as a thought... what kind of fuel pump does it have.... Facet cube or Airtex?
 

USAMilRet

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Hmmm. The unit that only generates 7Kw... What are the symptoms when you load it further... does the engine quit running, or does something trip up.
And just as a thought... what kind of fuel pump does it have.... Facet cube or Airtex?
Can't say as I am not in possession of the 803A at this time. It's not the gen but the motor that is choking at about 85% load. As soon as I get it, I'll start a new thread with all the relevant information.
 

Demoh

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For the beginning of the thread questions let me just say I have successfully done a 400hz to 60hz transplant. It was more of a full down to the skid restore of a unit and it turned out amazing. Did the same with all of the "scrap" from the donor and turned it into a table with a refrigerator inside.

As for the units you are looking at though, I would be weary if you havent decided to run away. If its priced right and you use the forums here and a lot of elbow grease then the 60hz that falls on its face might be your option. I personally would opt for a refund if its sounding like the seller cant figure that out if you were looking for a running unit.

Just to give you perspective, The last 802 I rebuilt after the 5 hr continuous 100% 5kw load I ran it another hour at 6000watts. All of the 803s Ive sold ran 10kw 5 hours continuous as a final test. This should be a MINIMUM standard for receiving a running generator (ive had a gen that would trip overload after 45 minutes, a quick test wouldnt have discovered that) and we make sure there are some other conditions the unit runs fine in.

Being that I rebuild these in my off time. I started with a bunch of units and I am down to 3 or 4 803s and 1 802. Delivered a nice 200hr unit a few weeks ago but most are lower hours than that. My partner that I rebuild these with and I do a whole lot more than fluids and hoses. We take all of the proper fixes (bulkhead fittings, quad, etc..) and a lot deeper level for refurbishing to make our units completely turn-key. (its more of a completely refurbished with the exception of paint kind of job for us)
 

Guyfang

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I have said it before, and will say it again. No gen set ever left my shop that did not run 6 hours at full load. That was the standard. Anything less was a no go.
 

Demoh

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I have said it before, and will say it again. No gen set ever left my shop that did not run 6 hours at full load. That was the standard. Anything less was a no go.
Hmm, looks like ill take my 5 hour test and add an hour to it. No complaints for an extra hour here.
 

zarathustra

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If the engine cuts out at a 7Kw load, but performs well up 'till then, I'd take a very hard look at the fuel lift pump. When a Facet pump works well everything is hunky dory.
BUT there are so few Facet pumps that actually work well I'd suspect the pump first.

The Facet pump was a high pressure, low volume pump and if it isn't working at 100% it just isn't going to "cut it" at the higher loads. A 90% Facet pump just won't do the job at high loads.

They don't make an E1074 Airtex pump anymore (if they ever really did in the first place, it could have been a re-tagged e8131), The e8131 is a low - medium pressure, high volume pump and has been swapped into units by people on this board and they report "yuge" success.

That could be the simple, minor solution that you expect.
 

Demoh

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FWIW even though it doesnt sound like this is the issue (I didnt see what the failure mode was in this thread, then again it was late yesterday when I read-through) if it was a problem where going past 7kw bogs the engine where it cant produce enough power to maintain 60hz it could be just really badly wet stacked. I only say this because I had an 802 I was tinkering with that was really badly wet stacked and could only sustain 3750 watts.

After hours and hours of running I was able to keep increasing load 250 watts at a time until I could sustain 5500 watts. While I was never able to confirm my diagnosis because I didnt take the top end apart, all clues lead to the diagnosis. It was a 6000hr unit directly from the base that used it and from what it looked like I can use my imagination to assume it was used to charge cell phones. I only bought it as a parts unit as it was advertised as a no-crank no-start I found the problem before I even got the unit home and other than the wet stacking it turned out to be fine. I still keep it as a parts unit though.

edit added: re-read, if he heard a noise maybe its running on 3 cylinders.
 
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justacitizen

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If the engine cuts out at a 7Kw load, but performs well up 'till then, I'd take a very hard look at the fuel lift pump. When a Facet pump works well everything is hunky dory.
BUT there are so few Facet pumps that actually work well I'd suspect the pump first.

The Facet pump was a high pressure, low volume pump and if it isn't working at 100% it just isn't going to "cut it" at the higher loads. A 90% Facet pump just won't do the job at high loads.

They don't make an E1074 Airtex pump anymore (if they ever really did in the first place, it could have been a re-tagged e8131), The e8131 is a low - medium pressure, high volume pump and has been swapped into units by people on this board and they report "yuge" success.

That could be the simple, minor solution that you expect.


Primary fuel pressure is very very important to any diesel engine. i would check the spec after the fuel filters and see what the pressure is when the engine falls on it's head.
 

csheath

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If the engine cuts out at a 7Kw load, but performs well up 'till then, I'd take a very hard look at the fuel lift pump. When a Facet pump works well everything is hunky dory.
BUT there are so few Facet pumps that actually work well I'd suspect the pump first.

The Facet pump was a high pressure, low volume pump and if it isn't working at 100% it just isn't going to "cut it" at the higher loads. A 90% Facet pump just won't do the job at high loads.

They don't make an E1074 Airtex pump anymore (if they ever really did in the first place, it could have been a re-tagged e8131), The e8131 is a low - medium pressure, high volume pump and has been swapped into units by people on this board and they report "yuge" success.

That could be the simple, minor solution that you expect.
Here was the fuel pressure/volume test I performed on my 803 just out of curiosity. My test was within the specs listed in the manual so they don't require a lot.
https://www.steelsoldiers.com/showt...ngs-MEP-803a&p=2044537&viewfull=1#post2044537


A Spectra SP8123 is a dead ringer for the Airtex E1074. I have not purchased or tested one but the only difference I see is the 1/4" NPT threads instead of 1/8" NPT. A brass pipe bushing would solve that issue. Not finding the Spectra web site any more so they may have folded. Found one on sale at Amazon but it didn't say in the specs it was 24 volts but the old Spectra catalog said it was.
 

VancleVector

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ca
Higher frequencies can use physically smaller and cheaper transformers; so 60 Hz would be preferred over 50.

Lower frequencies are less affected by skin effect; so 50 Hz is best here. Skin effect is where the AC current flows only on the outside portion of larger diameter wires, in effect increasing resistive losses in transmission lines.

The flicker of fluorescent lighting is more visible at 50 Hz, although this was probably not a consideration when the frequency standards were developed.
The frequency also affects the speed of AC motors and diesel generators. This is not an advantage so much as a design consideration.
 
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