MEP 831A

[grywitt]

Hello guys. Well I've continued with my new addiction. I bid on an 831A. My mistake it was an 832. Oops. I got it really cheap so no matter what it doesn't hurt much. Even if all I got was the engine out of the deal I would be happy. My question is is the inverter the only thing making it 400hz or does the alternator contribute to this. I know I can and will if I need to dig around in the TMs for the answer but I thought someone might know off the top of there head. If changing the inverter alone won't do it I saw they have a conversion kit for it this might be a great candidate for. Thanks for the input

 

[grywitt]

Also. What batteries have people come up with to replace the military battery it's supposed to have?

 

[grywitt]

I really wanted one of these gens until I read more about them. I like the design. Then I read they are pretty unreliable but since I've ended up with one I think I would like to try and make a go of it. They are a good looking gen and quiet. The one I bought only has 27 hours on the engine. I won't have the gen for a couple weeks so I don't plan on buying things yet but want to start sourcing parts so that once I verify the engine is good and the majority of the other parts. If I can't get a new inverter for it I'll probably get one of those conversion kits from kloppk. From what I've seen so far looking through the TMs I only need the inverter. The other thing is I won't have the gfi convenience outlet. If any one knows about something I'm missing I would like to hear it.

 

[fb40dash5]

I'm not sure if the governor controller in the 400hz is the same just adjusted, or different... either way, they suck, buy one of Kurt's.

If "All you need" is the inverter... well... I got some bad news. Look up how available they are, and how much. If you wanted to do something non-standard, like charge a solar bank, I've seen mention here that one could just rectify the output to DC, and not care that it started out as the "wrong" frequently... so there's that.

Personally, I'd look into converting it to a synchronous generator, which requires a new gen head & one of Kurt's controllers. I bought my 1st one not really aware that it's not exactly an "inverter generator" in the same way as a consumer inverter generator... it "idles" at close to full RPM, and any load brings it to full RPM anyway. My experience with mine is it's still plenty fuel efficient, mine runs a probably 1.5-2kw average house load on about a quart per hour.

I bought a 2nd parts machine to get a working load meter, and with the hopes maybe its inverter could be dried out (didn't seem to pan out) and now I'm halfway considering just swapping both of them to conventional gen heads & selling my one good inverter. Should put out an extra kw or so, and if you're running it for backup power on a house it's never really gonna idle down anyway since there will probably never be "no" load.

 

[grywitt]

Right on. I kind of like the idea of it being a regular generator any way. Thanks for the input

 

[2Pbfeet]

FWIW: For charging batteries, 400Hz rectifies into "cleaner" DC... absent off grid uses, I would look it as a source of backup parts, if needed. But YMMV...

All the best,

2Pbfeet

 

[grywitt]

FWIW: For charging batteries, 400Hz rectifies into "cleaner" DC... absent off grid uses, I would look it as a source of backup parts, if needed. But YMMV...

All the best,

2Pbfeet

Right. Once I bring it home and see what I bought I'll know more. Like I've said a couple times now I really like the looks of that gen and that diesel engine is sweet. I pretty much had myself talked out of getting one though then I half screwing around bid a small amount just looking at the pics and ended up buying one. I can imagine that 400hz really does rectify nicely. Are you taking about building an ac to dc converter or buying one already made? Heck I could probly use a windmill charge controller on the output. IDK. I'm a decent (heck pretty good even) troubleshooting electrician with a decent grasp on electrical circuits but I'm not a good fabricator. I do really well making things work again or maybe even differently but not good at starting from scratch

 

[2Pbfeet]

As I am more on the "hey, let's fabricate something" end of the spectrum, I was thinking more along the lines of "roll your own", going from 400Hz into a full wave rectifier and then with some EMI (capacitors and inductors tuned for 400Hz) giving you DC as input to a charge controller for a load bank. However, I have never really looked around to see what is readily available in the single phase 120V/400Hz area. At some point, @kloppk's conversion may be a more attractive route for you.

400Hz is a different case compared to 60Hz, and you should be aware of the greater reactance, giving larger wires more resistance than expected compared to 60Hz, but it isn't a huge deal at 3kW. Just be aware that "common sense" from 60Hz may not fully apply.

Again, if you got the MEP-832 at a bargain price, I think that the engine alone is worth the price of admission. Those L70/L709 engines are best in class, in my view.

All the best,

2Pbfeet

 

[grywitt]

As I am more on the "hey, let's fabricate something" end of the spectrum, I was thinking more along the lines of "roll your own", going from 400Hz into a full wave rectifier and then with some EMI (capacitors and inductors tuned for 400Hz) giving you DC as input to a charge controller for a load bank. However, I have never really looked around to see what is readily available in the single phase 120V/400Hz area. At some point, @kloppk's conversion may be a more attractive route for you.

400Hz is a different case compared to 60Hz, and you should be aware of the greater reactance, giving larger wires more resistance than expected compared to 60Hz, but it isn't a huge deal at 3kW. Just be aware that "common sense" from 60Hz may not fully apply.

Again, if you got the MEP-832 at a bargain price, I think that the engine alone is worth the price of admission. Those L70/L709 engines are best in class, in my view.

All the best,

2Pbfeet

Exactly!! I like that engine a lot. I wish I was better at that sort of thing. My dad had that skill too but me not to much. I think I'll probably end up using that conversion kit. I think the chances of finding one of those gens with everything perfect except the engine is slim. Lol. I have a harbor freight inverter gen that I converted to propane. I wish I could use those parts on that engine heck its 8kw but I bet that diesel would push it. At least a lot of it anyway. Back to me not being great at fabrication. I think for just over $200 dollars I'm not hurt any way. I happen to be going to visit a friend in the area so I can pretend I didn't have to pay anything for transportation too .

 

[Ray70]

Another option might be to use the engine and swapping out the inverter and alternator for a 4500W generator head, @kloppk used to sell a kit to do so, but I believe he recently posted the info on where yo source the generator itself and I believe he still sells the electronic pieces necessary for the conversion.
As for locating a 60hz replacement inverter.... not gonna happen. You'd be better off buying another 831 and use the 832 for parts.

 

[kloppk]

Yes, I still make and sell the conversion kits. Just shipped 18 kits earlier this week.
I can source the gen head if desired and have it drop shipped.

 

[fb40dash5]

As for locating a 60hz replacement inverter.... not gonna happen. You'd be better off buying another 831 and use the 832 for parts.

I haven't looked in a bit, but a while ago someone in the 'bay was selling takeouts, that were supposedly tested good.

But they were something around a grand IIRC, and I'd definitely agree with your latter sentiment. That money should handily buy the Mecc-Alte head & Kurt's board (and I'd call the board a wash anyway for a machine with the SLC100 in it)

 

[grywitt]

Yes I'm pretty sure I will be buying the kit from kloppk. The one other idea I had was that EG4 makes a thing called a chargeverter. It takes gen power and charges 48 volt battery solar batteries. I've got an email out to them to verify it will work with 400hz and if so I might just use it as a backup battery charger. I have a solar system and batteries so I mostly don't need to charge batteries but if it's cloudy long enough they can get low. Just a thought. Mostly I'm pretty sure I'm buying the conversion. I appreciate all the replies and ideas

 

[kloppk]

The spec sheet for it says 50-60 Hz input.

 

[grywitt]

Oh. Yeah it figures. It would be a good way to use it if it would work. I think using it to charge batteries would be awesome. Oh well. Thanks for checking. I looked earlier but didn't see that. It would be nice if I could find a way to make the 400hz work for something. It will be an awesome gen once I do the swap anyway.

 

[grywitt]

ha ha. Well I found one. Frequency converter that is. The only problem is its $4000 ha ha. HZ-AFC-1105.. I don't know if you guys have already found these but that is the model number and you can set it up for 120 or 120/240 60hz output with 120 400hz input. its 5kva. I will be doing the conversion still but I now know they build them. There is an 1800 watt one made to take on airplanes too and its $2000. I didn't know if you guys had found these so I thought I would share. I won't be buying one to test and report though.

 

[grywitt]

I did get a response from EG4. They confirmed 400hz was to high for the chargverter.