Need some GETT / Applied ECU / 23kw 3 Phase Generator Electrical Help

[kloppk]

I found a manual about the gen head at: Gen Head Manual
It talks about using a 12 volt battery with a 30 ohm current limiting resistor to apparently flash the gen head.
See PDF page 52

You may want to test the rotating diodes in the gen head. If they are toast the rotor won't generate any magnetism even though you are applying power to the static exciter.

 

[Scoobyshep]

I was just thinking diodes may need tested. Hopefully they aren't too badly burried

Sent from my SM-S908U using Tapatalk

 

[gotaconvoy]

Yes, when powering the coil with 27 vdc, the meter was showing .25 amp draw between the positive lead of the battery pack and the yellow wire/terminal.

So if I buy a variable power supply that can go up much higher, say 60 or 80 vdc, with adjustable amperage under 6, I should be ok doing what I've been doing?

What is the end diagnostic step? If the 9v trick worked, what would I be replacing? If this 80v trick doesn't work, what will I be replacing?

 

[kloppk]

Personally I'd suggest checking the rotating diodes next before investing in a DC PS.

 

[Scoobyshep]

this is bypassing the AVR by supplying current straight to the field. If it makes power this way the AVR may be bad (or there isnt enough magnetism to start the reaction(thats the ideal thing as the fix is a jump start and heavy load)) In the rotor assembly there is a set of diodes that rectify ac to dc for the rotor coil. if one is bad, it can cause the head to stop producing power ( essentially its shorting out the rotor coil, shorted coil=no magnet).

Next step if this fails is getting into the head and testing diodes. which can be rather unpleasent as they are on the rotor and usually a real {insert foul word here} to get to

 

[gotaconvoy]

kloppk

Thanks for the link! I'm reading it now. From what I understand, I need to find the diode bridge, then test the resistance in each diode. I'm looking for a high resistance in one direction, low in the other?

I have no idea what a diode bridge looks like or where on the genhead it is, so I'll be looking through the manual a little closer.

 

[gotaconvoy]

Scoobyshep

Ok, cool. I will see what DC power supplies I have around the house and may be able to cannibalize one for a higher voltage to try what we've been doing. I'll also look into the 12vdc / limiting resistor process kloppk linked.

If all fails, I guess I'm going diode hunting.

 

[Scoobyshep]

kloppk

Thanks for the link! I'm reading it now. From what I understand, I need to find the diode bridge, then test the resistance in each diode. I'm looking for a high resistance in one direction, low in the other?

I have no idea what a diode bridge looks like or where on the genhead it is, so I'll be looking through the manual a little closer.

They are easy to test when you can get to them its very important to disconnect one side when testing if you want any useable results. Most digital multi meters have a diode test function look for a symbol that looks like a triangle with a line through it. one way should show overload and the other continuity. Think of is as an electrical check valve.

 

[gotaconvoy]

[B]Scoobyshep[/B] ok, perfect. I was just reading the diode test section in the manual [B]kloppk[/B] linked and it lays out the procedure pretty clearly. I shouldn't have an issue once I can get to them.

I will also try and reflash the genhead as outlined in this manual.

Hopefully I'll have some results tomorrow if I can find a 30ohm resistor somewhere...

 

[peapvp]

Any of them $ 20 Chinese AVR’s with 5A to 8A will work.
Residual magnetism will last of up to 3 month if you don’t move Genset.
Magnetism will loose it self when magnetized part is exposed to vibration.
Physics 101

 

[gotaconvoy]

@Scoobyshep @kloppk

I got distracted by some other projects, but I'm finally tearing back into this generator. This morning I removed the rear vent cover to try and find the diodes. As expected, it was tight and I had to disassemble the generator body slightly, but I'm now working wide open with great access to the entire rear portion of the alternator.

I ended up looking at the diodes too hard and the leads disconnected from the diode body. They're obviously trashed and need to be replaced. Three questions:

1: In an attempt to get more access to the diodes, I removed the 4 long studs and 3 smaller nuts that hold the rear bearing housing in place. I tried lightly prying the housing off, but it doesn't want to come off. Instead of bashing it, I decided to consult the experts...how does it come off? Do I need to use a puller between the main shaft and the rear housing/cover?

2: Where should I source these diodes?

3: Before reassembly, is there anything else inside here I should replace as a precaution. I'd rather spend a few extra bucks on the unnecessary replacement of a component, than have something fail soon down the road which requires re-disassembly.

Thanks fellas.

 

[peapvp]

Could you please post some pictures of what you got there? So we know of what you’re looking at? Thanks

 

[gotaconvoy]

Yeah, after I posted I realized pictures would be helpful...haha. Thanks!

 

[peapvp]

Yeap, those diodes are toast. They are very uncommon. I would consult the Parts TM which should end in -24P
Please post part numbers once you have them.

 

[gotaconvoy]

Yeap, those diodes are toast. They are very uncommon. I would consult the Parts TM which should end in -24P
Please post part numbers once you have them.

Yeah, as soon as I touched the DVOM probes to the diode leads, they just crumbled.

Do you know how this bearing carrier comes off? Do I need to use a puller, or should it just pry off?

 

[peapvp]

Yeah, as soon as I touched the DVOM probes to the diode leads, they just crumbled.

Do you know how this bearing carrier comes off? Do I need to use a puller, or should it just pry off?

I am not sure. One of the more mechanically inclined members would have to answer that question

 

[gotaconvoy]

I am not sure. One of the more mechanically inclined members would have to answer that question

Right on; I appreciate it.

 

[Guyfang]

I would use a puller. Soak the thing for a day or two, and might even have to apply heat.

 

[Scoobyshep]

Puller is probably preferred

Digikey or newark is a good place to look

Might be worth looking at the possibility of replacing the bearing while it's apart.

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[Light in the Dark]

I use this brand for my pullers, very heavy duty (have a few different sizes): https://www.posilock.com/product-category/manual-pullers/2-and-3-jaw-manual-pullers/

I would replace the bearing at the same time, for certain. Cheap insurance.