Wet Weather Issue With MEP 831A

[Dan91d]

I have follow troubleshootings steps for circuit interrupter won't close and tested k1,k13 the switch itself. The circuit interrupter dummy light light up when I press it but contacts won't close. I have 120 vac coming from the top of the inverter box .the end of my testing procedures says replace k15 my orders of relays came in but they're DC . I can't find the number for the AC relays I'm pretty sure it's the k15.

My conclusion is the k8 ,f1,f2 or k15 is blown because troops like to plug everything in the gfci and when something pop they aquire clear relays and start moving pieces around

Any advice is appreciated
Where is the output contactor coil located ?

 

[Guyfang]

Output contactor is Figure 8, Item 4. NSN: 6110-01-507-7938
K-15 is NSN: 5945-01-260-3792

Testing the output contactor is easy. Gen set off, apply 24 volts to the coil and then test for continuity on the output terminals.

 

[Dan91d]

Thanks for your help sir output contact test is a go. The K15 was the culprit I found a working 3k and swap out the relay to test and the contacts close a provides 120 VAC at the lugs . I found another nsn for the k15 it is 01-509-9898 I fed log the one you provided and they both came up as relays one is cheaper than the other. To be safe I'm ordering both .

 

[Guyfang]

Good to go!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[ted50]

Good to go!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I have been reading the forum thankful that both my 831's don't have moisture issues. Then I got lazy and left them out and unforecast rain soaked them. They started up the next day and both generators showed overload when I tried the convenience receptacle. I ran them for an hour or so to dry them out but nothing changed. There was no power to the lugs so I did the load contactor test and had no power at A2 B2 but A1 B1 had good power. The continuity tests on S5 indicated it is good. So I'm in the same boat. TM says change K1. I checked K14 and K15 on one machine and they were corroded, K15 had loose particles in it. The K15 rely in the other machine arced originally when I tried the convenience receptacle and the starter on both machines grinds after start when the start switch is pushed up. I have K15 ordered but I am having trouble understanding how a bad K15 would prevent power to the lugs. If the new K15's don't fix the situation I will need to order new load cotactors but the NSN# I came up with doesn't work. Can anyone give me the proper #? Can K-1 be taken apart and cleaned? Thanks. And Thanks to Dewey38 for explaining ac vs dc relays because the TN says they are all the same as far as I can tell and I probably would have mixed them up.

 

[Dewie38]

K15 AC relay, supplies starter cut out and also supplies a ground through K12 to K1 so without K15 energized you cannot close K1,
and your starter will re-engage when the set is running.

 

[Guyfang]

The parts manual has been in error for years. The military hates to make changes to manuals. It cost money. Only the Good Lord will ever know how many relays were ordered and sent unnecessarily, because of this error. One of the reasons I loved always having a paper copy of TM's. You can write in them!

 

[ted50]

The parts manual has been in error for years. The military hates to make changes to manuals. It cost money. Only the Good Lord will ever know how many relays were ordered and sent unnecessarily, because of this error. One of the reasons I loved always having a paper copy of TM's. You can write in them!

Again THANK YOU. I have been trying to print the T.M. just for that reason but my printer won't do such a large item. I have been printing it in batches as I need it.
Dewey you are a wealth of knowledge.
I think I have finally mastered the T.M process and figured out the right K-1 number

 

[Dewie38]

Thanks ted50, there is a lot of knowledge on this forum.
I've been in the military generator industry for over 35 years, Guy worked on gensets in the military, Dieseladdict is an EE, just to name a few.
A lot of info here, a lot of experience, a lot of guys like yourself gaining knowledge by listening, learning, and doing.
No dumb questions here, don't be afraid to ask, better than trying without knowing and wrecking your equipment or worse hurting yourself or someone else.
No better feeling than taking a non operating diesel gen and repairing it, firing it up, closing the contactor and having power.
Good luck

 

[ted50]

Dewie, I just took a better look at the relays in both machines. I couldn't make out the markings originally so I just made sure I didn't mix them up. This time I got a magnifying glass and a strong light and found out K14 in one of the machines had the AC relay that should have been in K15. I tried it in K15 of both machines and problem fixed for both generators. 120V at both lugs on both machines and S5 light is lit. I am so happy. Originally Cord told me if it runs and makes power it is worth fixing. Good advice.
My comprehension from a computer screen is about nil and once I printed out what I could of the T.M's I began to understand the T.M organization. The T.M has a ton of information but it is also great to have "old hands" who will let you know when the manual is wrong or doesn't cover something like the K15 relay.
On another note. The Ebay seller I bought a non working L70 Yanmar engine from is sending me a 2nd engine because UPS banged it up pretty good. When I get it i will have some duplicate parts that I would be happy to pass along if anyone needs something. P.M. me if you do.

 

[Guyfang]

No better feeling than taking a non operating diesel gen and repairing it, firing it up, closing the contactor and having power.
Good luck

You know, that's the truth. I would have worked for free. Its just a wonderful feeling to find the problem and stand there looking at it run again.

 

[Guyfang]

Dewie, I just took a better look at the relays in both machines. I couldn't make out the markings originally so I just made sure I didn't mix them up. This time I got a magnifying glass and a strong light and found out K14 in one of the machines had the AC relay that should have been in K15. I tried it in K15 of both machines and problem fixed for both generators. 120V at both lugs on both machines and S5 light is lit. I am so happy. Originally Cord told me if it runs and makes power it is worth fixing. Good advice.
My comprehension from a computer screen is about nil and once I printed out what I could of the T.M's I began to understand the T.M organization. The T.M has a ton of information but it is also great to have "old hands" who will let you know when the manual is wrong or doesn't cover something like the K15 relay.
On another note. The Ebay seller I bought a non working L70 Yanmar engine from is sending me a 2nd engine because UPS banged it up pretty good. When I get it i will have some duplicate parts that I would be happy to pass along if anyone needs something. P.M. me if you do.

The reason for having standardised parts is understandable, and good. But the AC switch and the DC relays looking the same was dumb. I can not count the times I have seen this problem. Ted, This thread is good reading for anyone who has a TQG. Glad you got er running again!