MEP-831a Overload

[Jay722]

You were right, that TM is awesome. Do you know where I can get that 120vac coil relay fairly quick?

 

[Dwnorton1]

They are not uncommon. I suspect Amazon will have them or about any electrical supply house

 

[royerator]

Before the thread was hijacked, the discussion was about inverter shorts. I was having the same problem and realized that the inverter is not properly grounded because of the paint on everything the bolt head touches...then when there is a little moisture, whammo. so, what if you just isolate/secure the inverter with silicone caulk instead of bolts? I know, but it may run for yourself instead of scrapping it?

 

[robson1015]

These are fickle units- I bet they gave the military fits !!!

 

[royerator]

anyone know where to buy an inverter for a mep831 that has shorting issues?

 

[dav5]

I think you should listen to Dewie38 [post#2]. You can buy 831's way cheaper than a new inverter and you would have a parts machine as well.

 

[royerator]

roger, will look out for one.

 

[Guyfang]

Also keep an eye out every once in a while in the auction sites. GL and such. Last year I saw one or two inverters in lot boxes. Just labeled "parts" or "Electrical parts". I was just killing time, looking. You never know. I also remember NSN's well. I have a useless file of them in my moth eaten brain. When I see one, it clicks. Then I look up the numbers.

 

[royerator]

thank you Guyfang,

just a matter of time on GL out here in Hawaii...then that nice surprise one day!

 

[jmenende]

Might be moisture. With the unit off, open the voltage switch cover and leave it open. Fire the unit up and let it run at high idle for 15-20 minutes. Shut it down manually, close the cover and the restart. See if that solved the problem. The overload circuit appears to be very sensitive to moisture and will give a simular complaint.

This is the solution that worked for me. I live in PR where high humidity and heat is normal. I just remove the lower 6 pin connector and run it for five minutes with the top open since the fans wont work. After it heats up, turn off, plug the connector back in and voila!

 

[dav5]

This is the solution that worked for me. I live in PR where high humidity and heat is normal. I just remove the lower 6 pin connector and run it for five minutes with top open since the fans wont work. After it heats up plug the connector back in and voila!

I wonder if Kurt will come up with a fix. It sounds like he has an inverter disassembled.

 

[kloppk]

I do have two bad ones here that I'm trying to make 1 good inverter from. Both had catastrophic but different failures.
My hunch about the moisture issue with the inverters is the 13 potentiometers on the main control board. The pot's aren't sealed with CC like the rest of the board is and my suspicion is moisture is getting into them and wreaking havoc on the Overload and/or Over Voltage functions in the inverter. For some reason they aren't sealed at TRC after they've got them all adjusted, QC'd and ready to ship.
That's my hunch so far.
Kurt

 

[KEN2]

Ok, flipping the battle short must be a sequence critical because I tried flipping it before and it made no difference, but I thought that it wasn't effective on overloads. I'll try it again tonight.

mine runs @ 30 seconds unless flip battle falt then runs for long time. but not showing any power on meter. Any thoughts.? Thanks

 

[Guyfang]

Ken,

Start your own thread. That way, people who have never seen this thread will get a chance to see yours and answer. Some of the old folks do not pay much attention to real old threads.