garret gtp30-67 emu12/e troubleshooting

[thewhitestjamal]

Hows it going guys, stumbled upon this site today while doing some research on my recently acquired turbine project and thought i'd post up some pictures and videos for some of you seasoned turbine pros to look at since i find myself scratching my head. I'd like to say thanks in advance for any help you guys provide, looks like a neat community with some resourceful and imaginative engineers, glad to have joined! And although i will not be machining my own hand built turbine wheels or building a land speed bike, i'm hoping the tech that comes form this will help anyone else out in the future as well and if i get the little sucker to fire i've already been toying with using the powerplant for a willys flatfender rockcrawler, but only time will tell

I'm a recent A&P mechanic graduate who acquired the emu12 generator from a guy who had abandoned the project over 4 years ago when he burned up the starter and decided to give it to me to tinker with so i could get some hands on experience (after a month of nagging he caved and so the project began). I was able to rebuild the starter and get it to spin up but the generator was in pretty rough shape in regards to how it was stored and my gut tells me the igniter box has gone bad since it sounds like these are usually the weak link with these turbines (based on another owners statements) how can i test this out safely? is it true that these have radioactive material inside? know of any links to approved data? emu12 wiring diagrams? etc. theres a mile of wire in this thing most of which it looks like is for the generator portion

i was able to find quite a few videos of the gtp30's starting sequence and one video of the emu12, and some good tech on people wiring these up with there own control boxes but at this time i would like to preserve as much of the original equipment as possible since this is a bit of a military antique from what i've gathered, is that newb mistake thinking i can squeeze life from abused 1960's wiring? any hoo heres some pictures and video of the first start attempt, basically all i did that day was drain and clean the entire fuel system, (which took 2 hours since i found the drain plug for the tank 1.5 hours in) clean up some electrical terminals, bleed air out of the fuel system and hook up my freshly serviced starter, the starter worked great and my rpm and egt gauges seemed to be functioning normally........but thats about as far as i got before we lost the light, also in the video there is some howling from what i am assuming is the main bearing, your thought?


























heres the video of the first anti climactic run up
www.youtube.com/watch?v=xlk8Uf8nOeQ

<iframe title="YouTube video player" width="480" height="390" src="http://www.youtube.com/embed/xlk8Uf8nOeQ" frameborder="0" allowfullscreen></iframe>

[ernie wrenn]

Sounds like a fine start without the ignitor.

1: run a 24 vdc + wire over to the ingitor box. Find the + connnector and touch it, the unit should spark like hell. Check the ground terminal on the ignitor also.

1A: unplug ign module... insert meter in plug... attempt to start and check voltage.. If no reading follow above.

The bearings should be fine. Wait till you get a GOOD start before condeming the bearings, most of these units have low hours. Dirt and trash gets in the turbine and exhaust and will cause the sounds.

Ernie

[Richard OConnell]

I didn't hear anything in the video that sounded "strange," but its hard to tell anything without proper ignition. Like ernie said, the firtst thig you need to get squared away is that sparker. If need be, pull it out and test it buy directly connecting it to a battery. If it works, return it and try manually igniting it by leaving the spark running during the test.

It looks like a really nice piece and is easily worth the time to fix it up.

[thewhitestjamal]

thanks for the tips, ernie that sounds like sound advice, i'd be a happy man if the problem is a dirty ground cable and that is something i didn't bother to clean. I was warned by one of my teachers at school to be extremely careful when doing testing since these little suckers put out some whopping voltage, i take it all these tests should be done with the igniter in it original position?

richard, so at the very end of the video, that growl that is heard is of little concern? i'm new to turbines so it initially scared me and i thought it sounded like bearing stress but like you mentioned there is a good chance this thing has some junk in it. and from the hobbs meter and data plate it has been overhauled once in its life and currently has very little time on the hobbs. Also i did the test fires on pure red diesel, but i have access to plenty of sumped jetA, i know its approved for both but what are your experiences? i also read that guys will run a diesel avgas blend as well once again thanks for your time

Jamal

[Richard OConnell]

You can remove the ignitor to test fire it, but I would run wire directly to the battery to do that. I'm not sure on your exact setup, but a lot of generators and aircraft huffers have automatc ignitors. If this is the case, it would require you to start the entire unit and if the ignitors aren't working properly, you are just flooding the engine.

You need to test it independently of the fuel pumps. It should be producing audible and visible pops.

As for the growling sound.. In my experience with turbines, I have heard plenty of discerning sounds. A lot of times, what you are hearing is the actual gearbox that comes out and goes to your generator. Just make sure you check the oil levels and that you are using the oil specified. Most of these units use a very light weight oil. We use automatic transmission fluid for most of our projects since it's a little easier to find than military spec jet aircraft oil, but it gets the job done

EDIT:
Is it running on 12 or 24 volts?

[thewhitestjamal]

its running on 24 volts, i serviced the garret gtp30 with aeroshell turbine oil, since i'm an a&p it was easy to get my hands on the quarts needed, but at 12bucks a pop it definitely would have been cheaper running ATF, but is there a separate area for the gear oil i'm missing? and i was flooding the engine badly after a couple of attempts it was evident that if it did fire it off we were going to get a bad "hot start"

[Richard OConnell]

The hot start possibility is exactly why I was suggesting checking the starter alone. If it passes, you can just wire it to either the main start switch or to a new independent switch. It wont hurt the unit to keep the spark firing the entire time, even though it isnt necessary once youget a good flame. Keep us updated with your progress on it

[thunderbirdsarego]

Hi all, just found this site, and I have a couple of notes to add and questions to ask:

I have run both a JFS100 and a mates GTP30. The noises you have seem entirely normal. Some of my runs are here

www.youtube.com/user/SkyJeepAviation


I might add, as other sites note, the GTP30 will easily scare the pants of you if it runs up to 100% the first time. There is a lot going on, and if the shutoffs and sequencers are not working properly there is no time to act...

After many starts of the GTP30 and not getting more than about 60%, I dissasembled the fuel control governor finding the flyweights loose and in an unexpected position. Upon reassembly the start went off with a whoosh and stabilised at 95% which pleased me greatly.


A month or 2 later, by which time I'd installed the beast into the rolling test bed, on one start, the rpm went right past the 100% governor speed and I shut the fuel solenoid off.

Lots of careful retesting and setting of the overspeed microswitch to operate as it should, but without the problem fixed I removed the fuel control and examined carefully all the likely problem areas.

It felt to me like the fuel was getting past the main governor even after repeated reassembly of it etc. the only thing of concern was some groove marks on the shaft where there is a seal. I replaced the seal also polished the shaft. photo of shaft before polishing.

This work made no difference to the overspeeds.

I currently run with a controlled bleed on the acceleration control air line, this prevents the fuel pressure building past that required to run at 100% no load, and is satisfactory for my purposes.

I'm curious as to what may have caused this sudden change to overspeed, despite checking all the various regulators in the FCU I'm stumped for now

PS this site has info on the troublesome igniter box.

www.technologie-entwicklung.de/Gasturbines/GTP30-67/gtp30-67.html

I fixed one by replacing the main capacitor with a 1 uF 3,000volt and trigger capacitor with .05 uF 3,000 volt

another way is to use an automotive HID igniter, via a pulser circuit, and add gasoline to the fuel.

Ralph

Attachments:

[gaetan]

Does any of you GTP30 users has a manual or technical documents on the GTP30-150F type...

Thanks.

My test turbine is running on an industrial PLC unit. It was completely rewired and reprogrammed...
Would be nice to see what the correct technical specs are...described by the manufacturer. At this moment they are based on the specifications of the GTP30-140 something.

Its running at 60000 rpm and producing 2.1 Bar(g) at 1 kg air / sec.