MEP806 help

[draymorris]

RPM's good But not showing on panel meter, Unit will not produce correct voltage - about 25v (set on 20 an slowly goes up to 100v with switch in start position after running. Followed manual instructions and tested the "droop transformer" by making a quick brine load bank - the test showed only .2A ac produced by transformer - if I tested correctly. When the manual says to make 10 passes with 10ga wire - can I just wrap it around the coil (and of coarse thru the window) 10 times or does that make for a bad test by creating some kind of inductor?
Any thoughts on the test and or the problem is appreciated

 

[SandBar]

I am a novice in generators however this has the hallmark of a bad voltage regulator from my limited experience. I just picked up a 806a myself and waiting on fluids and filters to see what condition she is in.

 

[Guyfang]

Lets be a bit more clear. 806A or 806B?

 

[Guyfang]

Here is the list I told you about. You need to check if the entire Volt reg system is Libby or TRC. YOU CAN NOT MIX PARTS.

 

[draymorris]

806A
I found wire to Freq select sw on terminal 3 disconnected (looked like is came loose). Went ahead and put it back on. And re installed droop CT. Same results.
Potential transformer gets very hot when I flashed with the start switch for about 5 seconds - hot enough to start smelling. Using my thermal camera it looks like one side of the windings gets way hotter than the other. Assuming this could be a symptom or the problem but I need more education to know what to test.
Will look at the file you sent and keep studying. Any input is welcome.

 

[draymorris]

BTW - the Droop CT test did show it to be bad if I tested it correctly. But is it not only used when paralleling?

 

[draymorris]

Guyfang - I got an email saying that you responded when I checked my mail this morning - but when I open the thread it is not there. Still.
I opened a conversation with you yesterday but have not been able to figure out how to get back to anything called a conversation. I think I must be getting old.

 

[Light in the Dark]

You get to them here: https://steelsoldiers.com/conversations/

Should be just to the right of your username at the top of the forum.

 

[Guyfang]

Guyfang - I got an email saying that you responded when I checked my mail this morning - but when I open the thread it is not there. Still.
I opened a conversation with you yesterday but have not been able to figure out how to get back to anything called a conversation. I think I must be getting old.

We have that problem squared away now.

CT5? It should not get hot. Yes, for parra. operation.

 

[draymorris]

Yes, I see the envelope to go to the "conversation".
Got the info on testing the VR - here is what I tested:
Step 1 on the test - Disconnect wire from 1/A1 - test from term 1 to 10 3500ohms, same from 1 to 11 - so this is a fail. Right?
Step 2 - disconnect wire from term 12 - I get nothing from wire 133A to term 11,10,6 or 7

I stopped there. Need I go further?
Seem the VR and the Transformer is bad. Can I get replacement? From Where? Or do I spec aftermarket?

This is all TRC?

 

[draymorris]

When I say nothing on the circuit I mean Open circuit.

 

[draymorris]

What is the excite voltage output on these VR's?

 

[Guyfang]

What is the excite voltage output on these VR's?

Slow down a bit. Did you look at all 4 items in the circuit, to confirm they are all TRC or Libby. Before testing anything, you have to know if all parts are from the same company.

 

[draymorris]

I did not look at rheostat and resistor, mainly because unit was working and no one has replaced anything since it quit working. This may have been a bad assumption on my part, but can look at it tomorrow if you think I need to. This unit shows 1600 hrs on meter and shows no evidence of being worked on. Was purchased directly from gov auction about 5 years ago and set for a long time.

I can check on the rheostat and resistor tomorrow - 20K ohms on the rheostat, 1 ohm resistor.

I have so many projects going right now, the wind was blowing 50mph literally and cold, when I saw failed readings...just wanted to move forward.

Will let you know tomorrow.

 

[Guyfang]

Got you Lickin Chicken, (Loud and Clear). If it worked before, then no need to look at R16. UNLESS, its not there. You said there was a wire loose/disconnected on the S12, (Freq selection switch). There should also have been R16 hooked up there. See if it there and if its good. But it indeed sounds like the A1 and CT could be bad. I will ask Kurt how he is coming along with his A1 for the 15 KW's.

 

[draymorris]

I want to recap and pose a few questions:
When I flash the exciter with the start position of the master switch after the unit is running - I am sending 24vdc to the F+ from the crank disconnect switch?
When I do this the generator only develops about 100v and it seems that if I hold it too long the potential transformer powering the VR gets hot. What would cause this?
The steps 1 and 2 on the VR test both fail - as if something is wrong with the VR.
Shouldn't the generator produce full voltage regardless of the condition of the VR, when I am sending 24V to F+?
Enlightenment is welcome and maybe very needed.
Also, this unit was being used to power a barn with a few small(1hp) pumps and lights - single phase - could damage have been cause by having one leg being open. Seem like I read somewhere that leaving some transformer's with an open circuit can cause damage.