ok iam trying to figure out what i need to turn 400hz into 60hz, so i can use a surplus generator as a home backup power. 1986 Kurz & Root Co., MEP-115A, 60 KW, 400 Hz diesel engine generator set, serial number DZ00110, 120/208/240/416v, three phase.
at $400.00 hard to pass up if it will work some how.

 

Run at a slower RPM?????

 

Genheads are wound specific for a frequency, and although the frequency is partially dependent upon the RPM at which they are turned, they lose efficiency very quickly when they are varied much from their design frequency. It's commonplace to lower the rpm of a 60 Hz alternator from 3600 to 3000 in order to obtain 50 Hz, but a change from 400 to 60 is not at all practical. You need a new genhead wound for 50/60 Hz.

 

dont know much about electric but, this gen runs only at 2000 rpm so would think if i could slow it down wouldnt i lose some voltage power too and would need it reliable to run computers and tv's and not blow them out like the old school generators do, i know first hand )

 

Frequency converters are available but will probably be expensive. A 60 kW generator will consume a lot of fuel.

Timescope

 

400hz is common for aerospace and ground aux power for aerospace.

One way to do the conversion would be to convert to DC then use an inverter to get back to 60hz. The inverters are widely available from solar applications. The DC rectification is easy but the capacitors will be the killer. You might have been better off spending $4k on a 60Hz unit at the power level you need. I recommend disconnecting the Diesel engine, sell that and then sell the copper wire on the generator and start over.

 

lol yea then generator is a military one, as far as i can figure they have tons of them from old airplanes and sell them since they no longer need them at goverment liqudation.
after the storm sandy and had no power for 5 days was hoping to have somthing to run the hole house instead of my 5000 watt backup generator that cant run much but lights, fridge, and fan for fireplace.
Was thinking if to much to change would just sell it all for srap at 4400 lbs if my bid does win, find out in 3 days.
thanks for all the input.

 

Of course another alternative is to replace the 400Hz alternator with a 60Hz alternator.

 

One of the reasons they use 400Hz for aerospace is that all the reactives can be much smaller and lighter. That includes the windings in an alternator, so replacing it with a 60Hz Alternator is not practical. The 60Hz Alternator would probably be more than twice as large in length height and width and 4 to 10 times the weight.

The fact that this was a three phase system also causes issues.

You can do a lot with that amount of power, and that price is spectacular, but you would have to really know what you were doing and try to use the supplied power as is, or after DC conversion.

Somewhere out there I expect there are a few people who have gone down the path of trying to run a whole house or a houseboat, or an RV from 400Hz. There is certainly going to be an airplane customization shop or two that would be able to tell you what would be involved. I expect there is a forum for them to swap tricks. I am not sure I would like to hunt it down but I would probably be interested to visit.

 

I looked around and it appears there is a good sized population of backyard engineers trying to figure out how they could modify one of these IF they bought one. There is another group (usually more hostile on various forums) trying to figure out how to modify one because they ALREADY bought one. Nobody seems to have a good suggestion other than DC route. Nobody seems to have successfully converted one.

There does appear to be a business opportunity to help all of these people with there generators, unless they all bought and sold the SAME generator over the past 10 years of forum posts I found.

 

yea looks like every 1 buying them is spending from $200-$900 for these 400 hz generatore. 60 hz ones that are from 15 kw to 3 kw $1000-$3000 still cheaper than a new 1 but little small for what i need and already have a 5k gas 1.
i did ask a company about there 400 hz to 60 hz converters but they said there is nothing they have to do it, seems they only go other way 60 hz to 400 hz as i can tell.
ohwell live and learn, if i do have to get it since offer is on the table and i cant back out maybe it will work for lights atleast or ebay will find some 1 to pass it on too.
thanks all for you helpfull input, ill keep looking there got to be some one out there that has done it some how i hope lol

 

mep-115S ARE 400hZ ac GENERATORS (AS ALREADY ESTABLISHED).
..
There is no economical way to convert them to 60Hz power.
...
The best you can do is to rectify the power and feed as a Solar Power system back-up supply. (seems silly on the face of that statement - since the sun is more reliable than a generator - but that said...).
...
These are excellent power sources, you just cannot get 60Hz out of them. But, remember, Light bulbs, don't really care what frequency the power is at (assuming it isn't way off the planet...or microwave). So using a 400Hz power source for say lighting or cooking isn't that bad of a match.
...
I agree that there is a really big potential if you could build an economical retrofit kit. But retrofiting would definitely involve an alternator swap - which is in effect probably the most expensive component, not considering the governor and associated monitoring circuitry.
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Good luck..
..
Dave
Phoenix, AZ
Retired Air Force Programs Mamager
(and Tr-Tac Specialists, which used the MEP-115s until we got the LEG, and and LIPPs gensets into the inventory)
..
What are LEGs and LIPPS (Lightweight Engine Generator Sets (LEGS) and lightweight Initial Power Production Generator Sets (LIPPs)..).
...

 

wasnt sure if it could run lights, but now u added that i guess it could be used to run all the lights, stove and hot water heater that my 5k couldnt run because the 30 amps and them being 40 and 50 amps.
then generator is 220 115 amps so wouldnt be any problem for it till i can unload it or find a generator that some one has burned out the engine and i could strip the other parts out of it to change this one out.

 

I almost posted about lights and heat elements for cooking but I stopped.

Some fluorescent lights will work but others will not for example. Any high frequency ballast that rectifies the source AC is fine. The big old ballasts that work off of line frequency should be replaced anyway just to end the flickering.
Most incandescent bulbs will be fine.

Unless you had an extremely low tech oven range there will be parts inside that mind 400Hz. Three phase is even more of a deal breaker.

Any transformers, or AC motors will cause a serious problem.

The idea of pairing these gensets with a solar power system is a good match.

You wouldn't want to pay for the inverters just for emergency use. Making them part of your primary solar power with power company lines as a first line back up and your diesel gen as a third line is going to be a cost saver in the long run. The diesel gen is good for this at the price. Hurricane Sandy might have played havoc with a solar power installation.

You might also drop battery storage from this system by using the diesel as your night time supply.

 

wasnt sure if it could run lights, but now u added that i guess it could be used to run all the lights, stove and hot water heater that my 5k couldnt run because the 30 amps and them being 40 and 50 amps.
then generator is 220 115 amps so wouldnt be any problem for it till i can unload it or find a generator that some one has burned out the engine and i could strip the other parts out of it to change this one out.

Before you invest more money in a genhead (new or used), you should remove the genhead from the diesel engine for several reasons.

First, you want to be sure that you can get it off; they are always a tight fit and very difficult to remove. With this being a military product, I wouldn't be surprised if it is sweated on.

Second, you need to know the diameter, length, and shape of the shaft coming out of the engine. Most engines for generators use tapered shafts and there is more than one taper choice that might be used.

Third, you need to know the bolt pattern on the engine and make sure that your replacement genhead will bolt up.

Fourth, you need to know what the engine speed regulation method is, and if it relies on a signal from the genhead, which some do.

Of course, the replacement alternator must be designed to run at whatever the engine speed is optimized for. Many diesel generators run at 1800 rpm, but I haven't read about the one you have.

Then, there is the matter of the wiring, which can be quite confusing, but you can probably work that out.

All in all, what you propose to do is full of challenges. Good luck.

 

my only problem is the stove is a flat top with digital readout and not sure if it would blow it out or not. figure id test it out on my alarm clock thats on the fritz rite now and couple other junk stuff i got laying around.
i figure ill end up putting it on ebay for sale like coupl other people i see are too, but they want a lot money. if i brake even if it wouldnt work for me ill be happy.
thanks all for your help still got time to try anything.

 

well it looks like i dont have to worry about it any more some 1 just out bid my $500.00 max bin at last second.
kinda happy and not, would have bin nice to atleast try it out, oh well keep this in the back your minds and if any 1 finds ideas or where i could get CHEAP parts to change it over ill try again.

 

Congratulations?

Now we'll just have to wait for the "winner" to start posting the same question when they realize their generator is running at 400hz.

 

Lots of computer PSUs say something like "90-240 V". Most items that do not use a heavy transformer would run on DC (Stuff may blow up or burn up trying trying this, so one should know what one is doing before attempting). In recent years, a lot of personal electronics have moved from transformer -> linear regulator to rectification -> switching regulator due to the high cost/size/weight of 60Hz transformers.

Items such as computers, light bulbs, and stoves will often work with 120V DC. If you full rectify the output to DC, and then connect ONLY Switching Power Supply based items, you could use that if you could get the voltage right.

There was a member here who changed his entire basement over to DC, I haven't seen him around in a while, though.

 

There was a member here who changed his entire basement over to DC, I haven't seen him around in a while, though.

That sounds ominous.