Identifying Windings on 12 Lead generator
Identifying Windings on 12 Lead generator
(OP)
thread238-314092: Identifying Winding (leads) on 12 lead Generator.
Great post above~! I am in the exact situation...I've got a genset here that someone has cut all the output wiring. I've been able to identify the coils and yes, I did have to disconnect the diodes on the rear to identify the remaining 3.
Forgive my ignorance here, but it was stated to excite the gen with AC. The Gen I am working on does not have any AC plugs attached...how would I go about exciting it??
Thank you all in advance!
Great post above~! I am in the exact situation...I've got a genset here that someone has cut all the output wiring. I've been able to identify the coils and yes, I did have to disconnect the diodes on the rear to identify the remaining 3.
Forgive my ignorance here, but it was stated to excite the gen with AC. The Gen I am working on does not have any AC plugs attached...how would I go about exciting it??
Thank you all in advance!






RE: Identifying Windings on 12 Lead generator
RE: Identifying Windings on 12 Lead generator
Thank you!
RE: Identifying Windings on 12 Lead generator
RE: Identifying Windings on 12 Lead generator
I thought those were DC only...
RE: Identifying Windings on 12 Lead generator
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Identifying Windings on 12 Lead generator
I have 26 wires that come out of this 3 phase (25 kw) generator. I know power output by the markings.
2 of them have electrical clips on them which I assume go to an avr. That leaves me with 24 wires.
What I've done thus far.
With an ohm meter, I've checked for continuity on all wires. 18 of these wires pair continuity which I have separated.(9 pair) I've got 6 left that I assumed went to the diodes on the plate. I disconnected the diodes and there is no continuity with anything having to do with the remaining 6 nor any pair I've found.
I've researched the crap out of how generators work to how they are wired and still find myself...elementary...logic tells me that I have 24 wires....math tells me that I should be able to divide by 2 and come up with 12 pair, divide again by 2 and finally sum 6 leads... in which, I could excite and find the phases. But as mentioned above, 6 wires remaining and no continuity or similarity exists with the tests I've performed between the 9 pair and the 6 nor the 6 themselves...
Am I doing something wrong? Is the generator head broken? The only history I have behind this unit is that I was told a diode was bad and a little diagnosing was needed to replace it.
I rarely give up anything to the mouth of a dumpster!! What do I do?
Thank you for any help!!
RE: Identifying Windings on 12 Lead generator
Hope it helps, MikeL.
RE: Identifying Windings on 12 Lead generator
Thank you for the information...
I've got 24 wires coming out of the head that are not identified. How do I narrow those 24 to 6 pair to start testing phases with a battery?
18 out of the 24 wires ohm out to each other. That gives me 9 pair, if you will. However, there are still 6 additional wires left...Could this be a "dual wound" generator? Could the remaining go to a switch for polarity..ie...uvw, wvu?
Thank you
Chris
RE: Identifying Windings on 12 Lead generator
One thing you can try is to seperate all the leads, if this is a 12 lead two in hand (old terminology for two wires per lead) then using an ohmmeter you should find 4 of the wires with continuity. Once you have the six sets of windings grouped, if you have access to a Wheatstone bridge or a DLRO you should be able to determine which of the four wires are at which end of the winding. Then once you have them grouped into the 12 leads you can use the procedure and identify them properly. It helps if you assign temporary numbers to all of the wires and do up a drawings to keep track. I attached an old sample.
Last time I did this was several years ago with a 12 lead three in hand (36 total wires coming out)machine, it took about 7 hours and I had done this type of procedure before. You need to be methodical and patient, but you should be able to figure it out. Otherwise you may need to take it to a motor shop and they might be able to identify the leads after a partial disassembly depending on how the generator is built.
Hope that helps, MikeL.
RE: Identifying Windings on 12 Lead generator
First, Thank you so much for your time with this...
Is there any logical explanation as to why 18 ohm out to each other leaving 9 pair? Not knowing the history behind this head, I'd hate to put in the time and effort to try and figure it out if indeed, the unit is broken...
Chris
RE: Identifying Windings on 12 Lead generator
I am wondering if there was a partial burnout and someone cut the leads short to ensure that repairs would be done (Rewind) before there was an attempt to use the set again.
Does this machine have brushes or does it use a brushless exciter? On a brushless machine the diode plate is on the shaft between the brushless exciter and the revolving field. The wiring to and from the diode plate is along the shaft and is not in the main terminal box.
Does it have a PMG? (Permanent Magnet Generator, a small permanent magnet alternator on the back end of the shaft to supply power to the AVR)
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Identifying Windings on 12 Lead generator
Are you sure this is a "12 lead machine"? How do you know that?
Do you have nameplate info on this machine?
Can you provide a picture of the 24 wires that are coming out of this machine?
Is this a "standard" type generator, or some type of special purpose machine like a military MEP unit?
It really sounds like you need the services of a competent motor shop with generator experience, can you let us know where you are and maybe someone in the forum has a reputable contact they can point you to?
MikeL.
RE: Identifying Windings on 12 Lead generator
If you think I can get somewhere with this, I will build a small wooden jig to correctly separate each one of the wires in order to keep organization testing the fields. Please see the enclosed photos.
The wires wrapped in orange are the mystery...
Mike, I do know of one more shop that I could take it to. I will call them and see if they can identify...
Thank you!
RE: Identifying Windings on 12 Lead generator
First thing I'd do is add temporary numbers to all the leads
Next, is to megger test each lead to ground at 500 VDC, at a bare minimum you need to be above 1 meg-ohm, Newage prefers a minimum of 10 meg-ohms.
Next, use a DMM and measure each lead to very other lead, you should end up with 6 groups of 4 leads each that have continuity. If you don't have that grouping based on everything provided you have one or more open windings.
In my experience these chinese Newage tailends were terrible, where I worked at the time, we packaged a number of smaller rental contractor units with these and had a huge failure rate. Open windings were common, but grounded windings were most of the failures. Repair cost exceeded replacement costs and we ended up scrapping all of them in 2006 just before I left the company.
Attached is a Newage Fault Finding Manual you may find helpful.
MikeL.
RE: Identifying Windings on 12 Lead generator
Thanks again for the information.
After much research locally, I've been informed that you are exactly correct about the Newage Heads. I was not aware that there is a rewind shop fairly close to my location. After speaking with them, they told me that they could identify each of the coils but wouldn't be able to identify the phases. He also stated that even if I miraculously were able to get the machine to run, he would expect it not to run much longer. They've replaced 'thousands' of these heads with only a few hundred hours on them. He said they were a terrible design made with very low quality materials. He too stated that many of them had open windings. I am now VERY suspicious as to why this head is now laying in my shop. I believe my gamble with $200.00 USD and a bad diode is now down the drain. He said he knows exactly where to find a replacement and will quote in a day or so.
I thank you all very much for all the help with this, but I think I will heed the advice, chalk it up as a loss and move forward with a replacement head. Anyone have any use in Texas for a 200 lb paper weight? I have two of them! lol
Chris