NO Voltage or HZ reading on meters

[Rapracing]

Pull the cover from the side of the AC Reconnection box. The terminal block in question is literally just inside the box and probably the easiest area to work with. Locate position 5 and 6 on that terminal block. Disconnect the upper wire at 5 and 6. These go up to the VR circuit board. Wire up a 12 volt battery in their place, being careful to observe the correct polarity spelled out in the -34. I like to connect the wires first so I am sure not to short anything out. Once I have the wires attached to the terminal block, I then connect the battery, followed by starting the generator. If you do not get power generation then, your problem is below that level and probably somewhere within the AC Reconnection box. In that case, check the diode matrix at A4 carefully. If you do get power generation, your problem is one of the circuits on the VR circuit board, since that is the only part being bypassed for this test.

John

Thank You! I went out this morning and did the test before going to work. I have voltage so I guess that means the AVR board is bad.

It was working fine, Did I do something that would have caused it to just go bad?

Can it be repaired or do I just need to get a new one?

Good place to get one?

Thanks again

ETA: The voltage meter said 240 and would not adjust either way. I assume that is because the board is bad?

 

[Munchies]

The voltage adjustment could be bad as well. Swap the VR board out as a test. Make sure jumpers are set correct on the terminal board.

 

[Ray70]

Try taking a look at the resolution to a similar problem I had recently. http://www.steelsoldiers.com/showthread.php?111171-MEP-002A-are-all-Control-cubicles-interchangeable I was getting no power unless I continuously manually flashed the field, But the generator acted differently when I installed a J.R. H control cubicle instead of the original Libby. With the JR H I got output power but it would intermittently go high after the machine ran for a little while. Turns out my CVT was open at the H5-H6 terminals. I had heard an open CVT would cause output voltage to go high, but apparently it can also cause no output! Before you go replacing your VR board I would ohm out your CVT, only takes a couple minutes (and replace those bridge diodes) if the CVT checks out, Q3 on the regulator might be blown. If Q3 is the problem they are readily available on the internet for about $5

 

[Ray70]

What happened to Rapracing's comment saying he left the battery in place for a while then smelled something burning and found 4 of the A4 diodes had burned up?
I saw the comment then the SS site went off line for a while, now that post is gone
Can you confirm your bridge rectifier is now blown, in addition to the no power issue?

 

[Cycletek]

Patracy is updating the site so if the statement was made about 8:15 am it was lost during that process.....

 

[Rapracing]

Thank You! I went out this morning and did the test before going to work. I have voltage so I guess that means the AVR board is bad.

It was working fine, Did I do something that would have caused it to just go bad?

Can it be repaired or do I just need to get a new one?

Good place to get one?

Thanks again

ETA: The voltage meter said 240 and would not adjust either way. I assume that is because the board is bad?

Okay, so I called Delks again. William had told me last week that without a doubt it was the VR board, guess he was right.

Anyway, He told me today that you CANNOT leave the battery hooked up that it back feeds and that is why it destroyed the diodes on A4. He also said the voltage adjustment will not work with the battery in place of the VR board. That explains that.

Now I need a AVR board.....any good deals out there? and.....

either repair the A4 or buy one of them as well.

The test worked I just screwed up letting the battery connected while the engine was not running

ETA....Just noticed the previous post was gone. I had done the test removing wires from TB3 and replacing the VR with a battery. AFter I determined the the VR was the problem. I turned it off and came in the house for a couple of minutes leaving the battery hooked up. When I
went back out I smelled something hot. I had toasted 4 of the diodes on A4. That's the story

 

[Munchies]

Atleast the A4 diodes are not too bad to replace. Worst part is the lacquer coating (or whatever it is) Might as well do that large resistor on there was well. They burn up often

 

[Triple Jim]

If you've determined you definitely need an AC regulator board, I have replacements at what I think is a fair price. (see signature file below)

 

[n1oty]

The successful test with the battery, as outlined in the -34, proves a problem with the VR circuit board. If you have a decent meter that includes a capacitance test function, you can probably easily test the board components yourself. Absent such a meter, you can also examine the components visually for signs of overheating. Capacitors are a very common failure point. Examine the caps for bulging and/or oozing material. Electrolytics are especially prone to this oozing, but there are only a couple of electrolytics on the board.

Sorry to hear that you left the test configuration in place too long, but repairing that board should be easy.

John

 

[Rapracing]

Pics of A4 board front and rear




What diodes do I need to get? Part #? Any place special to get them?

 

[n1oty]

Part numbers or similar identifying markings should be legible on the remaining diodes, although you will probably need a magnifying glass. Alternatively, someone here on this board may have already done this research and identified the diodes, but a quick search I just made did not turn up anything.

On another note, have you tested the two diodes to see if they are actually damaged from the obvious overheating??? From your two pictures, the board is obviously scorched, but the solder joints do not appear to have melted at all and the picture of the diodes is not close enough to visually determine any damage (at least to my eyes). Personally, I would change the diodes anyway, but if they still test OK I'd concentrate on fixing your VR board problem first.

With diodes, the one usual problem that takes them out right away is exceeding the "breakdown voltage". Breakdown voltage is the maximum blocking voltage that the diode can withstand in its blocking direction. Exceed that maximum and it is usually an immediate kiss of death for the diode. A gradual overheating is generally a result of exceeding the current rating of the diode. This is certainly not good for the diode, but is not necessarily an immediate kiss of death. It is possible here that the overheating simply discolored the board and no other immediate damage occurred.

I'll try to take a closer look at your pictures.

John

 

[n1oty]

On second look, at least one of those diodes appears to have its markings completely scorched away. Just change them. I'll try to find a part number for you when I get in tonight, unless someone else comes up with it.

John

 

[Triple Jim]

Any of the 1N400X series (1N4001, 1N4002, etc.) will work fine. The 4001 is rated at 50V, the 4002 100V, on up to the 4007 at 1000V. All are 1 amp diodes. They are all inexpensive and available from the usual mail order suppliers. Radio Shack used to stock them, but I haven't checked them in years. I'd probably pick a 4002 or higher, just for spike protection.

You could go super heavy duty with 1N5408 diodes, rated at 3 amps and 1000 volts, also inexpensive, but you'd probably have to drill the holes in the board larger for the diode leads.

 

[Rapracing]

Radio Shack used to stock them, but I haven't checked them in years.

Thought I'd run in and check. I ordered 40 for $5.60. They want $1.49 each. I'll wait until Monday for them to get here

 

[n1oty]

Radio Shack lists a few different diodes from the 1N400x series, apparently topping out around 1N4004. The inventory finder for the Radio Shack's in my area all list the packages of 1N4004's as being in stock, so I guess this is a commonly stocked part at most (all???) Radio Shack's. Radio Shack also lists a 25-count variety pack containing 1N4001's through 1N4007's for $3.49. This also appears to be commonly stocked by the local stores.

If going through mail order, I like the suggestion of 1N5408's. Newark has them for about 22 cents per diode. The shipping will be more than the diodes, so the idea of extra beefy diodes appeals to me.

John

 

[Rapracing]

Yea Buddy!!!!!


The diodes came on Monday but I decided to wait on the VR board from Triple Jim.....

Anyways I started with the diodes this afternoon. After replacing all 6 of them I thought what the heck and fired it up. Everything was back to normal. Shut it down and fired it up 2 more times. All is well.

Guess I didn't need that VR after all.

AWESOME!!! I have a working generator and a spare board that will work in either the 002 or 003

Thanks again for all the help

 

[n1oty]

There can only be two possible explanations for the fact that you are now producing power after changing the diodes at A4. Either the diodes were already intermittently bad and they happened to operate properly during the battery test, or there is an intermittent issue at the VR circuit board. Intermittent electrical issues can be a pain. I know because I deal with them on a daily basis. The test in the -34 is accurate and valid. Given your results thus far, I suggest treating this as fixed, but watch for any signs of intermittent problems on the VR board.

John

 

[Rapracing]

I am hoping the diodes were the problem. I've started it a couple more times since an it seemed to be okay.

 

[Rapracing]

Well I finally took the time to get this thing attached and producing power to my house this morning. I ran it at about 60% other than when my wife decided to dry some cloths. It went up to about 105% when she did that.

I do have two questions.

The DC charging system was charging at a higher rate than without a load. When I ran with 5% or less it charged at just over 27v. Today with the load on it was charging at 30.8 - 31.3. Is that normal?

The other question is it ran for about 1.5 hours this morning and the hour meter didn't change. When I took the load off and restarted it worked.
Any ideas?

 

[steelypip]

The DC charging system was charging at a higher rate than without a load. When I ran with 5% or less it charged at just over 27v. Today with the load on it was charging at 30.8 - 31.3. Is that normal?

The other question is it ran for about 1.5 hours this morning and the hour meter didn't change. When I took the load off and restarted it worked.
Any ideas?

No on 1 - you should see battery stack voltage below about 29 volts at all times. If the batteries are OK, you're cooking off electrolyte, yes on 2: if it's the old-school mechanical-movement hour meter then it probably had grungy points which were 'surprised' into working with a combination of higher than normal voltage and vibration.