Sometimes it does. Other times it will show a 1500w load as 3,000 watts and rising. Usually at that point I bail on it and switch the load off. Right now it shows the load as something trivial like 500 watts. Dewie38 says there should be .857 ma at 3kW load at the back of the meter. I'll try to get that reading tonight.
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MEP-831a Troubleshooting
- Thread starter DieselAddict
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Ok, well that explains why the switch doesn't drop the load. One problem solved!
I attached the procedure I followed to adjust the speed. I set the speed to 254Hz, but I didn't adjust the linkage and I think I skipped step #9. I think I'll go back to reset the unit again to be certain I got it right.
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Dewie38
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Remember, you can't measure across the meter, you have to take one of the wires off the watt meter and put your multi meter in series with that wire and the watt meter.
You can't set full load speed when you are only loading to about half load. You have to get 3 kW worth of load and load from the load terminals and set no load speed and then full load speed.
Set no load speed and 5/16 gap on magnet and then apply 3 kW load and adjust boost pot on governor controller to obtain full load speed. Counter clockwise to increase speed.
You can't set full load speed when you are only loading to about half load. You have to get 3 kW worth of load and load from the load terminals and set no load speed and then full load speed.
Set no load speed and 5/16 gap on magnet and then apply 3 kW load and adjust boost pot on governor controller to obtain full load speed. Counter clockwise to increase speed.
R Racing
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Got my 2 mep-831a up from GA. Looked them over today. Started working on the nicer of the 2. It's missing the F1 fuse and k15. Took both from the other unit and tried it. But its dead as a door nail. No lights no gauges no nothing. Had it slaved for my mep-004a. Not a clue ??
R Racing
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I'm going to replace the fuse holder in the am as the cap doesn't seem to lock like they normally do. Also going to break out the meter and ohm the DC side since it all seems dead.
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I have some info about the power circuit in my first post. That will get you started on tracing the DC power.
R Racing
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Thank you !! I'll check that out tomorrow. I can't pull start this 1 as the rope is broke off and I'd like to see it run before I pull that all apart. The second unit seems to have a stuck governor ( As it won't budge at all threw the engine shaft? the linkage to the magnet moves freely) and the front panel is damaged pretty bad but repairable I believe. It bothers me that K15 was missing on the first gen along with the FU1 . That all seems to be part of the DC circuit. nothing looks cooked or burnt.
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Sounds like you have your hands full with those. Keep us posted on how its going.
Dewie38
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K15 and FU1 are AC so I doubt that has anything to do with your DC problem.
K15 is the starter cut out relay when there is AC voltage from the inverter this relay energizes and prevents you from re-engaging the starter.
FU1 is the AC to the battery charger, there is a separate winding in the PMA of 40 Volts AC to power the battery charger that fuse is in line with one of the winding leads.
K15 is the starter cut out relay when there is AC voltage from the inverter this relay energizes and prevents you from re-engaging the starter.
FU1 is the AC to the battery charger, there is a separate winding in the PMA of 40 Volts AC to power the battery charger that fuse is in line with one of the winding leads.
R Racing
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Thanks Dewie !! Maybe today I'll have better luck ?? Both units look usable but there always those gremlins! !
R Racing
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Ok Got a update !!
Found pin 17 on J7 green and funky. Cleaned it and voltage went from 14V to 25.5V Still nothing ! Found the 7 1/2 amp CB blown and read open. Swapped it from unit 2 . Still nothing. Checked the NC contacts on the E stop. They were burnt and read open. So I swapped the wires to the second set of NC contacts, And We have power !! Engine started instantly ! On the AC gauge it reads 100 VAC if you breath on the pot it jumps to 150 VAC . Its been hit by something and the shaft is bent and twisted. The muffler is broken. But I can TIG weld it up . I have no AC to the receptacle . If I check Voltage on the box back on the left with the switch . I have 114 VAC between L1 and L2 114 VAC between N and L2 . and 0 between N and L1 ? The switch is toggled forward to 240 VAC ? Any input would be awesome !!
Found pin 17 on J7 green and funky. Cleaned it and voltage went from 14V to 25.5V Still nothing ! Found the 7 1/2 amp CB blown and read open. Swapped it from unit 2 . Still nothing. Checked the NC contacts on the E stop. They were burnt and read open. So I swapped the wires to the second set of NC contacts, And We have power !! Engine started instantly ! On the AC gauge it reads 100 VAC if you breath on the pot it jumps to 150 VAC . Its been hit by something and the shaft is bent and twisted. The muffler is broken. But I can TIG weld it up . I have no AC to the receptacle . If I check Voltage on the box back on the left with the switch . I have 114 VAC between L1 and L2 114 VAC between N and L2 . and 0 between N and L1 ? The switch is toggled forward to 240 VAC ? Any input would be awesome !!
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When you say on the box on the back left.. You mean the inverter box? The terminals on the top of that one?
If you don't have 240v between L1 and L2 on that with the switch in the 240v setting that could be a problem with the inverter itself. Lets hope that isn't the case.
If you don't have 240v between L1 and L2 on that with the switch in the 240v setting that could be a problem with the inverter itself. Lets hope that isn't the case.
R Racing
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Yes the inverter box ! Ill try the switch in the opposite position tomorrow. The fan in the box is working as well. I'll see if I can find the part # for the inverter box. Something tells me it wont be cheap if it is bad 
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That is going to be several thousand dollars if you can find one. 
R Racing
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I found the company that makes them. Perhaps they have a program to repair my unit. If mine is bad I'll pull it apart and see what makes it breath lol
R Racing
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I guess what puzzles me is the front meter reads 100 vac. But L1 and N Read the same which is 0 ?
Dewie38
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Sounds like you either have a winding out on the PMA feeding the inverter or blown fuses on the inverter input.
There are fuses inside the inverter they look like resistors but are marked F1, F2 etc.
You can check the input to the inverter very easily by disconnecting the P15 and P16 connectors on the side of the inverter, start the set, it will run at max speed so you might want to adjust the black knob on the side of the engine half way between start and stop.
With a multi meter measure AC voltage on all the windings of the PMA at P15 and P16.
If you have all balanced voltages there then you have blown fuses in the inverter.
I cant tell you what the voltages will be because that depends on the engine speed so as long as they are balanced then you should be good.
You probably wont be able to get the inverter repaired by TRC so we may be in deep do do.
There are fuses inside the inverter they look like resistors but are marked F1, F2 etc.
You can check the input to the inverter very easily by disconnecting the P15 and P16 connectors on the side of the inverter, start the set, it will run at max speed so you might want to adjust the black knob on the side of the engine half way between start and stop.
With a multi meter measure AC voltage on all the windings of the PMA at P15 and P16.
If you have all balanced voltages there then you have blown fuses in the inverter.
I cant tell you what the voltages will be because that depends on the engine speed so as long as they are balanced then you should be good.
You probably wont be able to get the inverter repaired by TRC so we may be in deep do do.
R Racing
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any Idea what pins on p15 and p16 ? Thank you for your help !!
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Page 309 of TM-9-6115-639-13-and-P will give you the test procedure for the alternator windings. It includes the pin combinations.
R Racing
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Perfect thank you !! Would love a paper copy of the manual. The computer screen is hard on the old eyes lol.