30KW with Diesel Engine/ How to Prime Fuel System/

[Guyfang]

Tip: If the schematics are hard to read, you can also use the MEP-004A schematics. They are the same.

 

[Lugnuts]

You need to find another float in any case.

Now, we go into uncharted waters. The A27, ( special relay box).

Its the box in the rear bay with about a thousand C-Plugs hooked to it. Remove all the C-Plugs. Remove the 4, (If I remember right) hold down bolts. Take the A27 out. Remove the two screws that hold the cover and base together. The base get set off to the side. Look at the guts and see if there are any broken/ burnt wires. The look at the A5 card. million wires hooked to it. And broken parts? Burned parts? Signs of the card getting hot? Then remove the 4 nuts holding the A5 to the side of the box. Look at the back side of the card. Burns? Traces burnt through?

When you say the A27 Box where do I look in the manual for the explanation to the A27 Box? Is there a drawing show =ing where the A27 Box location/ Any recommendations on who to contact for a float?

 

[Guyfang]

Open the right side rear door. You can not miss it. Kurt posted an email address for a guy who has some parts to these gen sets. KURT, you there?

 

[Guyfang]

You can also test if the wires are good from the A727 too the pumps. Attached is a simple drawing. Hold the canon plug P5 in your hand. Look at the pins. Find LITTLE pin f and LITTLE pin r. Fix where they are in your head, or get a friendy slave to hold P5 steady. Then take a wire and attach it to the large starter lug, or any other place that is hot, (24VDC) and touch the other end of that wire first to the little f., (You should hear a pump come on. Then to the little r. The other pump should come on. Resist the temptation of letting them run very long. If you still have the float out, the tank will run over.

Do not forget to test CR27!!

 

[kloppk]

Yup, I'm here. Hi Guy!!
The gentleman to reach out to for the box is:
Dave Anderson
209-404-5226
Daveland@pacbell.net

 

[Guyfang]

This is the guy to call about parts.

Kurt, I have to punch out. Just watched the SpaceX launch, and its 00:25 here. Take care, stay healthy and will shout at you later today. Got another launch coming up in 7 hours.

 

[kloppk]

Get some shuteye Guy!

 

[Lugnuts]

So I have returned with the report/ After pulling said box I opened up the compartment and found how nice sized a modern day ECM is but with the box open you have the possibilities of repairing itself. I have attached 2 pictures of the A5 Card and I am asking if the R3 resistor would prevent the pumps from running. On the top side the photo does show discoloration and when turned of the resistor is not popped but does show discoloration. Not quite what one would say is for sure burnt up but enough to throw reasonable doubt that it is good.
Do you know what resistance R3 is? And since you seem to know a lot about the generator overall is that particular resistor right in the power grid of the fuel pumps.
I will comment that I have never seen printed circuit boards with such durability. The product was not built to go bad that is for sure! If you need better photos I will get them but would require some more disassembly.
Thank you

 

[kloppk]

R3 is a 1,500 ohm resistor.
It provides power to the diode bridge CR4 which in turn provides DC power to the K7 relay coil causing K7 to close.

 

[Guyfang]

Kurt,
What we are interested in is K5. That is the coil not marked, above and to the left of K8.

Lugnuts, how are you with testing things? A little AC and DC voltage? The A5 card can be checked with just a tad of care. The test is in the -34 TM. The relays are easy to test off the A5 card, or on the card.

The burn marks under the R3 do not look real bad, seen lots worse. Yes, the card was built rugged, but has a few weak points.

If you are not up to testing, or the card is bad and you are not up to fixing it, Kurt can and has done that.

 

[Lugnuts]

Gentlemen:
Frustration is kinda settling in and looking for the test of the A5 card hasn't been found. I don't seem to have the correct name for it. I went through the Card section for repair and diagnostics and couldn't even find a box that resembled what it is located in. I am asking for more help.
The other thing I noticed that in the -12 Operators Book that the schematic is there and I have attached it. It doesn't even show the presence of the A5 card. Have I got a correct schematic?
I think now that I'm through whining I will go smoke some Salmon!!!

 

[kloppk]

I posted the schematic of the A5 card a couple of posts back.
Here it is again..


Here is the test setup and test procedure for A5

 

[Guyfang]

Got to be cool dude. The TM 9-6115-464-34, page (PBF reader page number) is 311.
Cleaning, Inspection, and Repair of the component. Start reading there and go down. You will come to the passages Kurt attached to his message.

Also, there is a whole raft of schematics in the -12 TM. You pulled up only one. Go smoke some salmon, and spool down. Also, whats the date and highest change # for your book- The -12 TM had at least 17 changes.

 

[Lugnuts]

I posted the schematic of the A5 card a couple of posts back.
Here it is again..
View attachment 859524

Here is the test setup and test procedure for A5
View attachment 859521
View attachment 859522
View attachment 859523

Yes you did post that earlier, I just now know that I was looking at the whole card and not just a segment. And just a question for clarification, do I need to disconnect everything from the card for the test?

 

[kloppk]

Yes, It has to be removed to do the testing as I showed above.

 

[Guyfang]

Well, no. it is possible to do the test in the relay box. BUT, you are almost guaranteed to smoke test it, of give your self a wonderful tingeling sensation, when you place a finger in the wrong place. Guess how I know. Once was good enough for me.