803a Problem

[Knuckles]

I finally got it running. I took out all of the injectors and soaked them in PB blaster and used a brass brush to gently scrub them. The unit only had one hour on it so I don't think carbon build up was the problem. Maybe it we from sitting for a couple years and there was some rust or old diesel blocking them. Anyway, it started up and runs fine. Only issue now is the voltmeter does not work, I'm getting 140 volts out of the convenience receptacles and the potentiometer gets it between 140 and 155.

 

[peapvp]

Great! Check your VR board and see if you can calibrate the board per manual. If the VR board is not damaged then you will be able to reduce the output voltage back down to 100 to 130 range

 

[Knuckles]

After 3 months of working on this 803a I will finally declare victory. Everything functions as designed and within specified parameters. I load tested it for about an hour yesterday and everything checked out. This was a great project and I learned a lot from troubleshooting the many small issues associated with a genset that sat for 4 years without running. Now I can move on and get another project genset to work on!

 

[londonhous]

Some are diodes and some are resistors .Those noted as CRX (where X is number) are diodes, and those noted RX (where X is a number) are resistors. V is a varistor. I had to replace some on one of my 802A's and have some, so if burned up could send to you for a few bucks. Regards- Joe

 

[PETE01]

Hello M-35tom. I've been lurking around this forum for a while. I now own a MEP 803a with a newer engine and after exhaustive troubleshooting i believe I need a working stator and a voltage regulator. You say you have lot's of parts. Any chance you would have either of these available? We are practically neighbors, I live in Walkersville, MD.

All the best,

Pete Lebel

 

[m-35tom]

i don't have any spare parts but i have several working units if you need to check values on something

 

[PETE01]

Thanks for your response and your offer. I think I have the problem pretty well figured out. No Voltage on the quad winding (A7 to A8 )and very low resistance, .07 ohms instead of the .9 to 1.1 ohms specified. I changed the diodes on the voltage regulator, but it may require additional work, I don't know yet.

Do you know if there is a motor shop in Maryland which can rewind this stator? There may be an outfit in California that does them but it's too heavy to ship across country.

The engine sounds just sweet. No problems there. Nice machines. built for, well... you know!

Thanks,

Pete

 

[Guyfang]

Pete,

Did your gen set have no Quad circuit mod applied to it?

 

[PETE01]

Yeah. It came in wired direct. Blown out diodes in the Voltage regulator and dead Quad winding. No volts and very low resistance on theQ1-Q2 leads. I replaced the diodes and I'm pretty sure the Voltage Regulator is fixed but I can't check it until the stator is replaced.

I contacted Powertronics Inc. to see if they can provide me with a voltage regulator powered from the battery instead of the quad winding. The stator is otherwise good, all the windings check out and no shorts to ground. Armature is not discolored from overheating or anything. We'll see where that goes. There are so many 802's and 803's getting sold right now that I am sure this fix could be sold 100's of times.

Only other solution is use a big shackle on the D rings and use this thing as a boat anchor... (Just Kidding)... Engine is real strong. Only 400 hours on Tier 2 Reset.

 

[Guyfang]

Send a PM to DAYBREAK. He might have some extra parts. Cant remember if he has a stator, but the exciter/stator is the same for the MEP-802 and 803.

Lets start easy here. Just what parts do you think you need. Look them up in the parts manual. and write a list of part numbers/NSN's.

 

[PETE01]

Hi Guyfang. Only need two parts:

Stator: P/N 220-4236-02
Voltage Regulator: P/N 88-21063

Interestingly enough, I contacted Power-Tronics, Inc., in Texas this morning and they indicate that their XR8 Universal Voltage Regulator will work with the MEP 803-a Generator. Power to the VR is 120 volts AC, no need for the Quad winding. It's not a cheap way to go, ($400) but better than replacing the stator and the voltage regulator. Do you know of anyone "upgrading" a MEP-803A in that way?

Based on my testing, all of the armature windings are ok. All are in spec and none are shorted. These alternators are massive. Built for hard work.

I don't really care about not having the generator as close to stock as possible. As long as it provides power, I'm ok.

Have a great day!

Will send a PM.

Pete

 

[Guyfang]

Pete,

What I would do if I were you is to start a new thread. Label it, for instance, "Upgrading a MEP-803A and explain what you want to do. There are some people here who may have done what you want to do, and can help. Or, maybe some who have the two parts you need. Some of these people repair or reverse engineer parts for themselves. So a lot of good talent is available to you. But you get no visibility due to you tacking your information need on the end of a LONG thread, that may not get looked at much.

When you say stator, you mean the generator windings. Part number 220-4236-2, Item 43, in the parts manual. Item 43 is the combination of items 44-49. That's the main gen windings.

 

[PETE01]

Good point. Will do. Thanks