Mep 806A

[Insidious45]

Have an 806A that has no output voltage, have checked just about everything, when you hold the start switch the field flashes and as soon as you let go it drops frequency and voltage, holding the switch the frequency is good, but the voltage is still low and can't adjust, any ideas would be great.

 

[Guyfang]

I would say your volt regulator is bad. The excitor works, that's why you get voltage when you hold S-1 start switch up. You didnt mention any idiot lights, so I assume its not a safety shutting it down.

Do you have the TM downloaded so you can find the right Volt regulator?

 

[Insidious45]

I have an under voltage light, the individual that brought it to me had just put a new voltage regulator in it, I did some tests and it checked out, I am starting to wonder if its the undervoltage/over voltage relay

 

[Guyfang]

To test the Over/under volt relay, try this.

Start the set normally. Keep the S-1 start switch in the up/start position. Snap the S-7 Battle short switch up. Let S-1 go. Do you still have voltage/hertz on the meters.

What time is it there? its 11:17 here.

 

[Insidious45]

As long as I hold the start switch I have 60 hz, and I do have voltage 180 but no control of raising it with the pod, I did what you said and as soon as I throw the battle short the under voltage lights and I lose hz and voltage, I'm in Indiana

 

[Suprman]

Maybe someone swapped the regulator but didnt do the whole 4 piece change-over.

 

[Insidious45]

Well I just checked the over voltage and under voltage relay check per TM and when I disconnect wire 137 from terminal 5 on the regulator I am not getting a OVERVOLTAGE lamp and it says I should, and after that when I do the second test I am not getting an under voltage light and the AC circuit interrupter closes when it shouldnt

 

[Guyfang]

Do you get any failure message on the screen, after you let S1 go?

 

[Guyfang]

Maybe someone swapped the regulator but didnt do the whole 4 piece change-over.

What do you mean by 4 peice change over?

 

[Insidious45]

Yes, Undervoltage

 

[Guyfang]

Page 0004-7, Table 4. Diagnostic Controls and Indicators. This is a list of diagnostic controls and Indicators, (lights) that will help you find problems. Print it out and then go check them against the gen set. # 35 for instance, before and after you let the S1 drop back into the run position. There are several more things to look at. Your excitor works, that's why the set shows voltage and hertz when S1 is in the start position. And after reading what you tested, sounds like a volt reg problem. Can you get a known good one and try putting it in for test purposes?

 

[Guyfang]

Please show me a picture of your volt reg, or read the part number off the front of it.

 

[Insidious45]

I am not at work at the moment, they tell me they put in a new regulator, and it looks new, part # is good, I will put up a pick when I go in tomorrow,I do know they say they replaced the regulator and the power transformer, and with that they just threw it in and spliced it in.

 

[Guyfang]

Please ignore mesage # 11. At 23:55 last night, I sat up and wondered if you were using an A or B model. The whole time I thought you had a B model. Sorry. Will get out my A model info. Da*n I need to slow down and read more. Feel stupid.

 

[Guyfang]

Now, Right books.

I assume you started your troubleshooting with Chapter 4, AC Volt Regulator. Assuming has gotten me into much trouble, like message #11. So, have you performed the tests IAW the TM on page 4-1? If so, what did you come up with? I will say that having someone to help you do this is a good idea. Like your best friend. You will notice, there are three test procedures . For three different volt regulators. You have to pick the right test procedure out by noting the part number on the volt Reg.

Now I understand Supermans comment.

The components of the AC voltage regulator kits are not Interchangeable. Ensure the part number of the component to be Installed is the same as the removed component. Failure to observe this caution will result In equipment damage.

The people you got this gen set from may not have heeded this warning.

Volt Adj RheostatLibby	5905-00-556-3350		10K Ohm
Volt Adj RheostatTRC	5905-00-800-6696		20K Ohm

R16 Libby 60Hz Vreg	5905-00-106-9354		3 kohms
R16 TRC 60Hz Vreg	5905-01-460-2205		1 kohm

Volt Regulatr60HzLbby	6110-01-363-0494
Volt Regulatr60HzTRC	6110-01-384-7063

THe above listed parts are the TRC and Libby parts. The below listed part is the preferred AC volt regulator kit. You need to see if all the parts in your set, are the right ones that fit together. If not, I think Superman has the kits.

Kit Volt Regulator

6110-01-477-4851

I really need to make a list that is neat and tidy. If the NSNs are not on the parts, and you need to know what Part number goes to what NSN, let me know, I will look it up.

 

[Insidious45]

Here is a pic of the regulator, I know that they just purchased the regulator, and not as a kit, the power transformer they also put in looks suspect and is just spliced in

 

[Suprman]

Who makes the generator? It will be on the data plate. Libby or Fermont. The regulator you have is a libby. If you want to change regulators between brands the entire kit must be used. Regulator, pot, transformer and add a fuse in.

 

[Insidious45]

The regulator and the pot are the same, its the transformer that has me baffeled

 

[Guyfang]

You need to look at EVERY part to make SURE they all match. Just because the set was made by Libby, doesn't mean someone didnt upgrade it, sometime in its life.

As a matter of fact, that's why there is not a kit available from Libby. The military went away from the Libby system for a good reason.

When you say the regulator and pot are the same, you mean the pot is a 10 Ohm pot, right? And the transformer has what part number? Sometimes it's on the bottom, or right side, I think. In any case, the part number is there. And you need to check it and the Pot IAW the TM, as well as the Regulator. You don't know who they bought it from. Someone who tried to use it with a TRC system, and screwed it up. You don't know in what condition it was in before it passed into your hands. IF, all the part number match up, then TEST, it and not just once.

And for goodness sakes, don't forget the fuse and holder if there isn't one! You will hate yourself for forty forevers if you shoot the exciter rotor in the butt because of no fuse.

 

[Insidious45]

I have checked the pot and the regulator and they are the right ones, like I said, I havent been able to look at the transformer yet but it looks very suspect, I mean it looks like they picked it up at a **** radio shack.As of right now I see NO part numbers and it looks very generic.