Two Auction MEP-803A Starting Issues..... Different on Each unit.. HELP??

[Daybreak]

Question... What size fuse is supposed to go into the FU2 holder? Right now I just have a piece of Aluminum tubing.. lol

For my other MEP-803A I'm keeping, I'm going to add this fuse to the A1.

Thanks again for all your help!!

Howdy,
What are you calling the FU2?


That is the quad winding fuse mod.

Military MEP generator reset information

PDF page 29 has the MEP-8xx 5kw and 10kw fuse mod (Fuse, 3A, 600V Time Delay FNQ-R-3 5920-01-322-6986)

 

[Guyfang]

DO Not run the set without the fuse. The reason it's there is to protect the main gen. If the A1 goes bad in a over volt situation, it will burn up the Excitor windings. All sets are supposed to be modified, but as we see every week, it's not true. Get the fuse, and install it. If you have other gen sets, do them too. A fuse is way cheaper then a main gen. Daybreak's link to the reset info gives you the info you need to get up to snuff on your gen set. It's better to know, then not know.

Glad you got it up and running.

Now, the other set. Makes voltage, doesn't read on the meter. I asked you if you can use schematics. The wires from M1, AC volt meter run back to S6, terminals 15 and 30/32. Measure voltage there while running. If you have no voltage there, the switch is bad, or miswired. If you have AC voltage at terminals 15 and 39/32, then something stinks in your wires to the meter.

 

[Jayco36REQS]

Howdy,
What are you calling the FU2?
View attachment 713724

That is the quad winding fuse mod.

Military MEP generator reset information

PDF page 29 has the MEP-8xx 5kw and 10kw fuse mod (Fuse, 3A, 600V Time Delay FNQ-R-3 5920-01-322-6986)

Yep, that is the one.... It's the first Gen (out of 8 I've had), I've seen with this fuse holder in it. Is it an easy fuse to source? Local Lowes or have to order?

I definitely plan to put one in any and all future Gens I find without it!!

Thanks Guys... MUCH appreciated!!!

 

[Jayco36REQS]

Ok, read the document... GOOD READ!! Have the parts ordered to make the Quad Winding fuse mod... Got everything to do 5 Gens for $60.

 

[Jayco36REQS]

Yes, I can read a wire diagram... Once I got my readers out.. (WOW tiny writing!! lol)

OK, From S6-15/13 to M1 I get 83-volts. When I test the convenience outlets or L1/L3 I get the proper 120/240 volts, and the voltage adjuster switch adjust ac volts up or down perfectly.
The S6 switch does feel a bit gritty when I cycle it (with unit turned off of course) Someone mentioned cleaning it... Is there a writeup on that procedure?

Anyone have any other ideas?

 

[Farmitall]

Yes, I can read a wire diagram... Once I got my readers out.. (WOW tiny writing!! lol)

OK, From S6-15/13 to M1 I get 83-volts. When I test the convenience outlets or L1/L3 I get the proper 120/240 volts, and the voltage adjuster switch adjust ac volts up or down perfectly.
The S6 switch does feel a bit gritty when I cycle it (with unit turned off of course) Someone mentioned cleaning it... Is there a writeup on that procedure?

Anyone have any other ideas?

I just went through this same situation. Check your PMs

Both my S6 and S8 were gritty and M1 not reading. Cleaning the switches solved the problem with mine.

 

[Jayco36REQS]

Well after an entire can of CRC contacts stray, and wd40, and compressed air, and cleaning all contacts with a brass cone dremel wheel.... this switch STILL doesn't work right. It works on 3-phase, but single phase it still doesn't show voltage on the voltmeter.... The gen makes power fine, and I swapped another S6 switch from another gen and everything works perfect... so it's definitely the S6 switch. I tried the OHMs test procedure as-per the TM, but its giving weird readings.... so either I try to disassembly the switch (which I've heard is a nightmare), or I have to buy a new one... which I haven't seen for less than a reasonable price.

 

[Farmitall]

Well after an entire can of CRC contacts stray, and wd40, and compressed air, and cleaning all contacts with a brass cone dremel wheel.... this switch STILL doesn't work right. It works on 3-phase, but single phase it still doesn't show voltage on the voltmeter.... The gen makes power fine, and I swapped another S6 switch from another gen and everything works perfect... so it's definitely the S6 switch. I tried the OHMs test procedure as-per the TM, but its giving weird readings.... so either I try to disassembly the switch (which I've heard is a nightmare), or I have to buy a new one... which I haven't seen for less than a reasonable price.

I'd try switch disassembly, what do you have to lose? If nothing else it will give you an idea of its construction and you might be able to clean up and burnish the offending contact inside.

I'd do it on a clean white towel and lay the parts out as you take it apart. Maybe even have a video rolling for assembly reference. If its the blue plastic type, it appears to be nothing more than a bunch of pancake rotary switches with a common shaft and the splines down the sides that hold it together.

If you have a bad part inside that can't be resurrected, there's no telling if you'd ever be able to source it.

I'd like to get a hold of a bad one just for the experience of disassembly to see how its constructed.

 

[Zed254]

Might try the folks at Electroswitch. I bought a new S1 from them as described here: https://www.steelsoldiers.com/showt...2A-803A-S1-Master-Switch-Source-Electroswitch

You'll need to confirm from TM that Electroswitch makes the S6 (my S6 looks like their work) with NSN number then communicate with factory as above. It won't be cheap, but my S1 was brand new OEM quality and works like a charm.

I did some hunting for the NSN of this switch: a challenge but finally found info in the Tier 2 document TB-11-6115-741-24.

3.7.9 On 5-60 kW A TQG’s only: If a new style sealed switch is not installed, replace the S6 Rotary VM-AM
100% with the new style sealed switch, Electroswitch part numbers 31907LW (5 & 10 kW) or 31904QT (15-60
kW), or American Solenoid part numbers DHR10 C57430 EF or DHR10 C57420 EF, respectively. The Control
Bracket may need to be bent backward slightly to accommodate the switch. NSN 5930-01-531-2977 (5 & 10 KW)
and NSN 5930-01-531-2975 (15- 60 KW).

Search with the model number (31907LW) on the big auction site: they are available....

 

[Jayco36REQS]

UPDATE......

Ok, I took the switch apart last night.. diligent about marking the position (and taking photos) of every gear, plunger, housing orientation, etc as I went through the stack of the switch.

**For those saying it's a crazy "complex" switch... nahh... it's actually VERY basic technology. It's just a stack of basic gear/plunger actuated connector plates to connect the circuit between the terminals. Also, there are internal and external bridges connecting various terminals together. Anyway, so long as you take your time, and mark the orientation of EVERYTHING.. It's easy! But what I learned is you really don't have to take it apart to clean the contacts. you can see the contact points once the switch is out and outter bridges removed. It's easy to see what is active on what setting and also if there is excessive dirt/corrosion.

Surprisingly, the cleaning worked.. all of the terminals and screws OHM tested perfect... Once back together, it was the cycle that the TM said which ones were supposed to be "active" during what switch setting that was still throwing me off. Long and short... APPARENTLY, someone in the field had taken the switch apart, and put the knob barrel gear back in 180 deg out... Thus why I was getting screwy readings on different switch cycle settings. I removed the knob-barrel, reoriented it 180deg, put it back in and tested all of the switch cycle settings... PERFECT!!

LESSONS LEARNED:
1- Clean with CRC contact cleaner first ( I used a whole can) Flood it at all contact points, rotate the switch frequently as you go, Blow it out with compressed air, Rinse .. repeat
2- Spray with WD-40 and rotate the switch as you go.... blow with compressed air
3- Final clean with CRC cleaner one last time... rotate and blow it out good.
4- If you need to disassemble... Sharpie works perfect for marking orientations of EVERYTHING
5- Number the housings as the alignment rails with the numbers come off
6- Remove the 2 Top screws that hold it all together, Remove the square mount plate, remove the knob barrel gear, then FLIP IT UPSIDE DOWN CAREFULLY and work from the BOTTOM UP!!
7- Each switch section has 2-springs, 2-plungers, 2- contact plates, 4-terminals w/screws, and some have 1-internal bridge.
8- Go SLOW removing each section as the spring will FLY!! lol I used a tiny flat tip jewelers screw driver to hold the barrel-gear as I was removing each section.

Hope this helps ... YES... I know I should post pictures, but I wanted to get the update out here. I'll come back and add in some pics when I get more free time this weekend.

Hope this helps other!

 

[Farmitall]

UPDATE......

Ok, I took the switch apart last night.. diligent about marking the position (and taking photos) of every gear, plunger, housing orientation, etc as I went through the stack of the switch.

**For those saying it's a crazy "complex" switch... nahh... it's actually VERY basic technology. It's just a stack of basic gear/plunger actuated connector plates to connect the circuit between the terminals. Also, there are internal and external bridges connecting various terminals together. Anyway, so long as you take your time, and mark the orientation of EVERYTHING.. It's easy! But what I learned is you really don't have to take it apart to clean the contacts. you can see the contact points once the switch is out and outter bridges removed. It's easy to see what is active on what setting and also if there is excessive dirt/corrosion.

Surprisingly, the cleaning worked.. all of the terminals and screws OHM tested perfect... Once back together, it was the cycle that the TM said which ones were supposed to be "active" during what switch setting that was still throwing me off. Long and short... APPARENTLY, someone in the field had taken the switch apart, and put the knob barrel gear back in 180 deg out... Thus why I was getting screwy readings on different switch cycle settings. I removed the knob-barrel, reoriented it 180deg, put it back in and tested all of the switch cycle settings... PERFECT!!

LESSONS LEARNED:
1- Clean with CRC contact cleaner first ( I used a whole can) Flood it at all contact points, rotate the switch frequently as you go, Blow it out with compressed air, Rinse .. repeat
2- Spray with WD-40 and rotate the switch as you go.... blow with compressed air
3- Final clean with CRC cleaner one last time... rotate and blow it out good.
4- If you need to disassemble... Sharpie works perfect for marking orientations of EVERYTHING
5- Number the housings as the alignment rails with the numbers come off
6- Remove the 2 Top screws that hold it all together, Remove the square mount plate, remove the knob barrel gear, then FLIP IT UPSIDE DOWN CAREFULLY and work from the BOTTOM UP!!
7- Each switch section has 2-springs, 2-plungers, 2- contact plates, 4-terminals w/screws, and some have 1-internal bridge.
8- Go SLOW removing each section as the spring will FLY!! lol I used a tiny flat tip jewelers screw driver to hold the barrel-gear as I was removing each section.

Hope this helps ... YES... I know I should post pictures, but I wanted to get the update out here. I'll come back and add in some pics when I get more free time this weekend.

Hope this helps other!

OUTSTANDING!!!!

Thanks for the update and congrats on resolving your problem!

What was the surface condition of the contacts that you viewed, were there any flash/burn marks or was it just improper orientation of the knob gear?

Good work.

 

[Jayco36REQS]

OUTSTANDING!!!!

Thanks for the update and congrats on resolving your problem!

What was the surface condition of the contacts that you viewed, were there any flash/burn marks or was it just improper orientation of the knob gear?

Good work.

Thanks! When I pulled the switch, it was REALLY dusty... and sounded and felt "gritty" when turning the knob....so I first blew it out with compressed air. Several of the contacts and screw terminals had a greenish or dark film on them and ohm ck showed issues, which either the CRC or a quick tap with my small brass wire cone on my dremel got those cleaned up easily. Every thing "looked" clean after the CRC/DW40/CRC cleaning process... But when ohm testing as per TM, it still didn't make sense. So I went through each contact set (1-2, 3-4, 5-6...etc) ohm testing, and turning the knob to see if I got a good test when contacts were touching.... all tested fine when contacts were touching. (side note.. it took me awhile to figure out what I was looking for and looking at in the tiny area where you can see the contacts to terminals... once I took it apart.. it was an AH HAH moment..lol)

Once I knew what I was looking at and looking for, it was an easy time to look to see what contacts were touching at what switch cycle setting... and waaalaaa... easy to deduct what the issue was.

Now that I know what they look like inside, I doubt I will ever need to take one of these apart in the future unless the contacts/terminals are burnt off. I could even cut an emery board( aka nail file) down to fit between the contacts and sand them if needed if they don't ohm test when touching.

I will try to post some pics as to what to look for.

These MEP-803A units are fun to learn. lol

 

[Farmitall]

Thanks! When I pulled the switch, it was REALLY dusty... and sounded and felt "gritty" when turning the knob....so I first blew it out with compressed air. Several of the contacts and screw terminals had a greenish or dark film on them and ohm ck showed issues, which either the CRC or a quick tap with my small brass wire cone on my dremel got those cleaned up easily. Every thing "looked" clean after the CRC/DW40/CRC cleaning process... But when ohm testing as per TM, it still didn't make sense. So I went through each contact set (1-2, 3-4, 5-6...etc) ohm testing, and turning the knob to see if I got a good test when contacts were touching.... all tested fine when contacts were touching. (side note.. it took me awhile to figure out what I was looking for and looking at in the tiny area where you can see the contacts to terminals... once I took it apart.. it was an AH HAH moment..lol)

Once I knew what I was looking at and looking for, it was an easy time to look to see what contacts were touching at what switch cycle setting... and waaalaaa... easy to deduct what the issue was.

Now that I know what they look like inside, I doubt I will ever need to take one of these apart in the future unless the contacts/terminals are burnt off. I could even cut an emery board( aka nail file) down to fit between the contacts and sand them if needed if they don't ohm test when touching.

I will try to post some pics as to what to look for.

These MEP-803A units are fun to learn. lol

IXNAY on the Emery board, much too coarse! A clean dollar bill would be a much better choice than an emery board.

There are much better products to use to burnish/clean relay and switch contacts.

Again, great job! and yes it is very rewarding to learn about and get good results trouble shooting these sets.

 

[Jayco36REQS]

IXNAY on the Emery board, much too coarse! A clean dollar bill would be a much better choice than an emery board.

There are much better products to use to burnish/clean relay and switch contacts.

Again, great job! and yes it is very rewarding to learn about and get good results trouble shooting these sets.

Yea I know CRC isn't the best... but Walmart had it on hand., and I would usually start with a bottle of Coke first (old Navy Trick at sea)... but I was all out! lol The emery board I was looking at is actually a polishing board (maybe 1600 grit), not the rough grit a-typical boards.

Thanks for the kind words.. I figured I couldn't break it more.. since it didn't work. lol I have always been the type to geek out and take stuff apart to see how it works. so this was a fun project.

 

[Farmitall]

Yea I know CRC isn't the best... but Walmart had it on hand., and I would usually start with a bottle of Coke first (old Navy Trick at sea)... but I was all out! lol The emery board I was looking at is actually a polishing board (maybe 1600 grit), not the rough grit a-typical boards.

Thanks for the kind words.. I figured I couldn't break it more.. since it didn't work. lol I have always been the type to geek out and take stuff apart to see how it works. so this was a fun project.

CRC is fine for the liquid cleaning portion of the process, it's non residual and doesn't attack plastics, components or circuit boards. Regular 90% isopropyl alcohol is also a good start in most instances. Then there are combination type cleaning and lubricant sprays that will also work well depending on the application and whether a lubricant is necessary. I keep CRC electronics cleaner on hand always and use it on many things.

I was mainly speaking of the mechanical polishing of contacts. Using high powered magnification, the surface of a contact would look like the Rocky Mountains if a regular emery board were used and it would foul that much quicker in the future. Clean smooth and shiny is the desired outcome.

By all means....Stay away from any type of chlorinated spray cleaner, it is a death sentence to most plastics.