Mep002 will not stay enegized

[Mattpingel]

I purchased an mep002a about a year ago and it's worked quite well yesterday I'm using it to power the house after a storm it ran for about 4 hours and then stopped generating power when I go out and energize generator again rolling the switch to the start position to energize the generator it will generate power but only as long as I hold the switch rolled over to energized fields does anybody have any ideas or suggestions thank you

 

[Chainbreaker]

First off, welcome to Steel Soldiers! Lots of good members here to assist you with help in troubleshooting.

My thoughts are it could possibly be a bad exciter stator in gen head since it is producing electrical power only when it is being energized in the start position.

If you haven't downloaded the TM's go to the top of this pg. and select the "TM". Go to about the 3rd page and you should find the MEP-002a TM's. You can download all of them from there. You want the -34 TM. Chapter 8 includes some tests, though they may be bench tests IIRC. Regardless it gets pretty involved if your not skilled with troubleshooting generators and don't have the right test equipment. There may be other ways to test to determine if the excitor is the culprit. I've never had a bad one so no experience with doing so.

If the exciter were to be found to be bad I recall they run right around ~$125.

 

[Mullaney]

I purchased an mep002a about a year ago and it's worked quite well yesterday I'm using it to power the house after a storm it ran for about 4 hours and then stopped generating power when I go out and energize generator again rolling the switch to the start position to energize the generator it will generate power but only as long as I hold the switch rolled over to energized fields does anybody have any ideas or suggestions thank you

.
Welcome to the outfit!

Hate to admit it, but I don't have a clue about generating power. Like Chainbreaker mentioned, the TM's will help you a lot. Not really exciting reading, but those books are the key to making things work.

Would be nice to have a few pictures posted here on your thread - just in case somebody asks.

 

[Mattpingel]

First off, welcome to Steel Soldiers! Lots of good members here to assist you with help in troubleshooting.

My thoughts are it could possibly be a bad exciter stator in gen head since it is producing electrical power only when it is being energized in the start position.

If you haven't downloaded the TM's go to the top of this pg. and select the "TM". Go to about the 3rd page and you should find the MEP-002a TM's. You can download all of them from there. You want the -34 TM. Chapter 8 includes some tests, though they may be bench tests IIRC. Regardless it gets pretty involved if your not skilled with troubleshooting generators and don't have the right test equipment. There may be other ways to test to determine if the excitor is the culprit. I've never had a bad one so no experience with doing so.

If the exciter were to be found to be bad I recall they run right around ~$125.

Thanks for the info I will download them and get reading it's a nice generato well worth fixing where do you find parts? Thanks again

 

[Mattpingel]

.
Welcome to the outfit!

Hate to admit it, but I don't have a clue about generating power. Like Chainbreaker mentioned, the TM's will help you a lot. Not really exciting reading, but those books are the key to making things work.

Would be nice to have a few pictures posted here on your thread - just in case somebody asks.

Thanks for the reply I'm going to download. The TM and get reading Thanks again

 

[Chainbreaker]

Thanks for the info I will download them and get reading it's a nice generato well worth fixing where do you find parts? Thanks again

To find parts there are several options:

1. Go to eBay and type in "MEP-002a" and search on that. Then also do a search using "MEP-003a" since ~90% of those parts are the same.

2. Using the TM -24P Parts Manual look up the part you are needing and use the NSN (National Stock Number) & the description of that part to search for that particular part using Google search engine. If you don't get any hits try using a variation of terms with NSN + mfg's part # & part description.

3. Sometimes you can find parts or a complete "parts generator" on Craigslist.

 

[Triple Jim]

You're not getting exciter field current from the usual source. When you hold the switch in the start position, current is supplied to the exciter from the 24v battery. In normal operation it comes from the X windings of CVT1 (X1, X2, X3), goes to the diode board to be made into DC, then straight to the exciter field. The output from CVT1 is controlled by a small current from the regulator board that goes through the control winding of CVT1 (terminals C1, C2). Some possible causes of the problem:

1. Failed X winding of CVT1
2. Failed diode board
3. Regulator failed and is putting out full control current to the control winding of CVT1 (terminals C1,C2)

"1" can be checked by measuring the resistances of the X windings per the -34 manual.
"2" can be checked by testing the six diodes on the board.
"3" can be checked by disconnecting the wire from terminal 17 of the regulator and taping the end so it doesn't make contact with anything. Then run the generator and see if you get power. If you do, it'll probably be 170/340 volts or something near that.

When you're checking the resistance of the X winding of CVT1 it's probably worth checking the other windings of that transformer too.

I don't think the exciter has a problem because in the start position the current from the 24v system is applied to the exciter, and that's giving you power output.

 

[Mattpingel]

You're not getting exciter field current from the usual source. When you hold the switch in the start position, current is supplied to the exciter from the 24v battery. In normal operation it comes from the X windings of CVT1 (X1, X2, X3), goes to the diode board to be made into DC, then straight to the exciter field. The output from CVT1 is controlled by a small current from the regulator board that goes through the control winding of CVT1 (terminals C1, C2). Some possible causes of the problem:

1. Failed X winding of CVT1
2. Failed diode board
3. Regulator failed and is putting out full control current to the control winding of CVT1 (terminals C1,C2)

"1" can be checked by measuring the resistances of the X windings per the -34 manual.
"2" can be checked by testing the six diodes on the board.
"3" can be checked by disconnecting the wire from terminal 17 of the regulator and taping the end so it doesn't make contact with anything. Then run the generator and see if you get power. If you do, it'll probably be 170/340 volts or something near that.

When you're checking the resistance of the X winding of CVT1 it's probably worth checking the other windings of that transformer too.

I don't think the exciter has a problem because in the start position the current from the 24v system is applied to the exciter, and that's giving you power output.

Thanks for the help just got the TM's downloaded and will try to do your 3 tests soon thanks again for the help

You're not getting exciter field current from the usual source. When you hold the switch in the start position, current is supplied to the exciter from the 24v battery. In normal operation it comes from the X windings of CVT1 (X1, X2, X3), goes to the diode board to be made into DC, then straight to the exciter field. The output from CVT1 is controlled by a small current from the regulator board that goes through the control winding of CVT1 (terminals C1, C2). Some possible causes of the problem:

1. Failed X winding of CVT1
2. Failed diode board
3. Regulator failed and is putting out full control current to the control winding of CVT1 (terminals C1,C2)

"1" can be checked by measuring the resistances of the X windings per the -34 manual.
"2" can be checked by testing the six diodes on the board.
"3" can be checked by disconnecting the wire from terminal 17 of the regulator and taping the end so it doesn't make contact with anything. Then run the generator and see if you get power. If you do, it'll probably be 170/340 volts or something near that.

When you're checking the resistance of the X winding of CVT1 it's probably worth checking the other windings of that transformer too.

I don't think the exciter has a problem because in the start position the current from the 24v system is applied to the exciter, and that's giving you power output.

 

[Triple Jim]

Thanks for the help just got the TM's downloaded and will try to do your 3 tests soon thanks again for the help

You're welcome. Nothing is guaranteed though... including my help.