MEP-831a Troubleshooting

[Guyfang]

54-575g

• Circuit interrupter always closed - FIXED, thanks to explanation from kloppk.
• Voltage adjust ineffective, though effects engine revving a little bit - Haven't tested pot, this is on back burner for now.
• Positive battery wire ring is toast from loose connection arcing - FIX IDENTIFIED
• Speed controller linkage out of adjustment - Back burner for now
• Overload light lit
  • Overload indicator even with L1, N, L2 disconnected from A8.
  • I still get AC voltage output (though not enough voltage, but possibly due to engine speed adjustment) with light lit.
  • Opening or closing the voltage selector door doesn't seem to change voltage output.
  • It doesn't cause or attempt to shut down engine.
• You need to check the A2 fault indicator out. Test procedure in the book. If you have a generator that works, try swapping the A-2 with that one. I think the contacts in the A-2 are welded shut that provide power to the light. The A-2 is a pluck and chuck item if I remember right.

 

[OverkillTASF]

You need to check the A2 fault indicator out. Test procedure in the book. If you have a generator that works, try swapping the A-2 with that one. I think the contacts in the A-2 are welded shut that provide power to the light. The A-2 is a pluck and chuck item if I remember right.

Somehow I always bottom-post... You or someone else suggested this. I do have another A2 that I'll pull out and see. Assuming it's not easier to actually test the relay output from A8.

 

[OverkillTASF]

I'll replace the circuit interrupter light (since the whole assembly was knocked off one of my generators) with this:
http://www.digikey.com/product-detail/en/apem-inc/Q12P1CXXG24E/679-1585-ND/1953550

IP67 protection, just doesn't have the "press to test" functionality. I'm not sure how important that is, really, but I suppose I could also wire in a small momentary switch right next to it for that. The whole Dialight assembly otherwise is like a $40 part. Ha!

 

[tburk49760]

Hello all, interesting read. Just took delivery of my mep831a2007 model with 21 hours! Drained excess oil, filled up fuel tank and hooked up the Nate cables to Raqi (my LMTV) and she fired right up! Seemed to be spinning a bit slow but I hooked up a 500 watt light and it is producing power. Low fuel light stays lit even after a reset and neither the e stop or regular stop switch have any effect. I plan on putting a meter on it tomorrow to check output hertz and voltage. Even after reading al, this awesome info, I only have the faintest idea where to start. Magnet adjust? Smack procedure on the governor? Gain adjust? Sometimes if it flip the start switch to off then on again it will die while in the on position... Looking forward to resolving these minor issues and using this as my backup to solar at my off grid tiny home! Thoughts?

 

[DieselAddict]

Hello all, interesting read. Just took delivery of my mep831a2007 model with 21 hours! Drained excess oil, filled up fuel tank and hooked up the Nate cables to Raqi (my LMTV) and she fired right up! Seemed to be spinning a bit slow but I hooked up a 500 watt light and it is producing power. Low fuel light stays lit even after a reset and neither the e stop or regular stop switch have any effect. I plan on putting a meter on it tomorrow to check output hertz and voltage. Even after reading al, this awesome info, I only have the faintest idea where to start. Magnet adjust? Smack procedure on the governor? Gain adjust? Sometimes if it flip the start switch to off then on again it will die while in the on position... Looking forward to resolving these minor issues and using this as my backup to solar at my off grid tiny home! Thoughts?

Hi,

You'll need to troubleshoot the low fuel light. That is cutting the DC control power and keeping the speed controller from working.

Have you downloaded the manual and looked at the electrical diagrams?

Don't adjust the throttle linkage or anything until you have no alarms.

 

[tburk49760]

Awesome! Thanks for the heads up! Reading the tm now. I did study the laminated docs that come in the unit and it got me thinking about the fuel level I presume float switch. Should be easy to meter that out.

 

[DieselAddict]

Yea, its a float. You'll find the connections behind the engine. If you look behind and to the right of the alternator.

 

[Guyfang]

Tburk.

The manual gives you all the info you need to test the fuel level switch. Normally, because the sets have sat forever and a day someplace, empty, the float hangs up. You can also simply remove the switch, check range of motion and replace it. This fixes it about 99 times out of a 100.

Eyeball the floats while you have the switch out. JP-8 ( the standard military fuel), is not real good for the float material. Sometimes it simply ate up the float material, leaving the three magnets that are supposed to be in each float, laying on the bottom of the tank. The top float controls low fuel light. The bottom float turns the set off when the tank is almost empty. And like Chris said, don't fool with the throttle linkage yet. First the low fuel problem, then see if you have a fuel cutoff problem.

 

[tburk49760]

Slowly plowing through the tm. Thanks so much for the input. Just for giggles when I went to work this morning I went out and started it and it fired right up made power and shut right down via the switch. The low fuel light was not on. This evening, the fuel light issue was intermittent. I will pull the switch soon. Any idea where to get a replacement? I plan to mount a 30 amp receptacle soon also. Noticed there was no fiuse in the holder behind the control panel...

 

[Cord]

Yea, its a float. You'll find the connections behind the engine. If you look behind and to the right of the alternator.

There are two floats. One for the fuel gauge and one for the light. The fuel gauge has several small screws holding it in and the light is simply a round switch. Although others say that you should never need to adjust the magnet, I was never able to get mine to shut down without adjusting it. It's a fine line between shut down and surge and I still need to fiddle with it on occasion.

 

[Cord]

Slowly plowing through the tm. Thanks so much for the input. Just for giggles when I went to work this morning I went out and started it and it fired right up made power and shut right down via the switch. The low fuel light was not on. This evening, the fuel light issue was intermittent. I will pull the switch soon. Any idea where to get a replacement? I plan to mount a 30 amp receptacle soon also. Noticed there was no fiuse in the holder behind the control panel...

Try Dan at oldsurvivor39 at aol dot com. 352-two three one-0733 I've bought from him several times now with good results.

 

[Guyfang]

Although others say that you should never need to adjust the magnet, I was never able to get mine to shut down without adjusting it. It's a fine line between shut down and surge and I still need to fiddle with it on occasion.

No, no. We have not said, do not adjust the magnet. We said FIRST solve the other problems, THEN if you have to, adjust the magnet.

Tburk, first check the switch, you may only need to pull it and clean it up. Or exercise the floats, to get it to work right.

 

[DieselAddict]

Yea, +1 on when to do the throttle adjustment. Do it but just don't do it until the end when you otherwise have a good running set.

I also recommend using a spring scale to set the pull-off strength of the magnet. You can spend an hour tweaking it and it will half-ass work or you can set it in 5 minutes with a spring scale and know its right. I know, I've done it both ways.

AND... If you set it with a spring scale and you still have problems, the problem is NOT the magnet. Look elsewhere. Been there done that one too.

 

[OverkillTASF]

I just realized this thread isn't a sticky or anything... it's not supposed to be the monolithic MEP-831A troubleshooting thread, I guess. I'll end up making a few new threads for questions regarding my specific MEP-831A's. Sorry!

 

[Guyfang]

Let us know when you do.

 

[tburk49760]

Had other work this weekend. Got to play with it a bit today after it was on the magic battery fixer all weekend and the battery seems to be ok. Put a 20 amp fuse in the holder behind the control panel and it fired right up and shut down properly! I put some Lucas fuel addative in the tank Thursday in hopes of the float freeing up and it does act much better. Stil not right though. Likely pull it in a few days. Time to replace the three fuel filters and see if that cures the occasional stumble.

 

[buggsy458]

Hey all, I'm brand new to these generators and picked up two recently. The one that I have dedicated the most time to runs but the GFCI trips about 30 seconds into putting any type of load onto the three prong plugs in the front. I'm wondering if anyone can give me advice on figuring out if it is the GFCI or something else. I'm no mechanic but I do believe that if you can read you can succeed. Thanks for any advice/tips you can give me.

 

[OverkillTASF]

You can take the GFCI module out, wire it to your home wiring, and see if it trips there. If so (and your home wiring is correct), you know something! Or wire a known good GFCI outlet in place of it and see if it also trips. Note the GFCI is a convenience outlet, and is only rated for 10 amps. The GFCI does not apply to the main terminals.

 

[Cord]

Grab a three prong plug in electrical tester from a big box store. You'll need one which has a button to test the GFI. Plug it in and see if it holds and then trips when you push the button . If it doesn't, the GFI is probably bad.

 

[buggsy458]

Ok, I took a GFCI out of another unit, exchanged it into this unit and it still pops the GFCI breaker after about 40-60 seconds. I'm not 100% sure that the GFCI I switched out isn't bad also but I do plan on getting a tester tomorrow from the big box stores. On the chance that the GFCI is good what else could be causing it to pop the breaker? I'm only testing it with a 1500w heater so it shouldn't be that.

Does anyone have a good video of wiring one of these through the either main terminals? Thanks!