Voltage regulator Died Again

[Niko182]

Anyone know anywhere I can get it repaired ASAP. I have a check ride on the 12th and its quite inconveniant that it died right now.
I know maxwell fixes them But is there anywhere close to socal?

[MB65E]

Don can turn them quickly. If it’s the Mooney dual voltage regulator. Don was the only one that I found that fixes them. 

-Matt

[MIm20c]

Off memory you are using an alternator that has 50% more output reserve than is normally used on Mooney 550 aircraft. Might be the reason you fried the VR so quickly.  Might want to look at replacing the alternator with the proper size...

Other parts like the drive coupling, wires, etc might not be as easy to replace during the next overload.  Just being that guy I guess. 

[MikeOH]

11 minutes ago, MIm20c said:

Off memory you are using an alternator that has 50% more output reserve than is normally used on Mooney 550 aircraft. Might be the reason you fried the VR so quickly.  Might want to look at replacing the alternator with the proper size...

Other parts like the drive coupling, wires, etc might not be as easy to replace during the next overload.  Just being that guy I guess. 

Help me understand your comment better...

IF his alternator has the ABILITY to put out more current than a standard one, then an OVERLOAD is just that: something ELSE wrong that needs to be addressed.  So, how does going back to the 'standard' alternator fix the underlying issue?  Seems to me it only masks the real issue.

Further, my admittedly limited understanding of VRs is that they modulate field current to maintain a constant voltage under varying load conditions.  As such, does the field current really rise to a level that will fry the VR?  I'd be curious to know just how much, in Amperes, the field current actually rises over a 'stock' alternator at max output when the alternator is putting out 50% more than standard.  An alternator is basically a mechanical power amplifier; i.e., 50% increase in output does NOT mean a 50% increase in required field current.  Along those lines there is a field circuit breaker.  Unless that has been changed out for one of larger capacity, I find it even harder to believe the oversized alternator is responsible for frying the VR.

But, I'm open to counter arguments to my points.

[Niko182]

6 minutes ago, MikeOH said:

Help me understand your comment better...

IF his alternator has the ABILITY to put out more current than a standard one, then an OVERLOAD is just that: something ELSE wrong that needs to be addressed.  So, how does going back to the 'standard' alternator fix the underlying issue?  Seems to me it only masks the real issue.

Further, my admittedly limited understanding of VRs is that they modulate field current to maintain a constant voltage under varying load conditions.  As such, does the field current really rise to a level that will fry the VR?  I'd be curious to know just how much, in Amperes, the field current actually rises over a 'stock' alternator at max output when the alternator is putting out 50% more than standard.  An alternator is basically a mechanical power amplifier; i.e., 50% increase in output does NOT mean a 50% increase in required field current.  Along those lines there is a field circuit breaker.  Unless that has been changed out for one of larger capacity, I find it even harder to believe the oversized alternator is responsible for frying the VR.

But, I'm open to counter arguments to my points.

I also agree with this. If I'm wrong please let me know, but I don't think its the alternator power. I think the quality of the alternator could have something to do with it. The alternator only puts out 15 amps when everything is on. I don't think the voltage regulator is working harder just because there's a bigger alternator. I wouldn't be surprised if the alternator is causing the problem, but I don't think its because its puts out more amps than the stock one. For a while the Alt field breaker has been popping when I would turn off the alternator master switch at lower RPMs. I don't know why but I've called hartzell a couple times and I could still never get someone to pick up. irritating to say the least.

[Steve W]

I don't speak voltage regulator, but I could see a situation where a mismatched alternator tries to draw more field current(lower field resistance) than the regulator is designed for and contributes to a shorter life. 

[MIm20c]

I’m not going to comment further as I don’t have anywhere near the necessary understanding of the system. I would think the (momentary) surge right after the switch was engaged might affect certain parts of the system.  

I will say that after a 26 amu out of pocket adventure the charging system can bite if its not happy. 

[MikeOH]

31 minutes ago, Steve W said:

I don't speak voltage regulator, but I could see a situation where a mismatched alternator tries to draw more field current(lower field resistance) than the regulator is designed for and contributes to a shorter life. 

Certainly plausible.  Again, though, if the circuit breaker is unchanged it seems less likely; it current limits to protect the field circuit which would include the VR.

[MikeOH]

40 minutes ago, Niko182 said:

Snip...

For a while the Alt field breaker has been popping when I would turn off the alternator master switch at lower RPMs. I don't know why but I've called hartzell a couple times and I could still never get someone to pick up. irritating to say the least.

Hmm, what is "a while?"  If "the when" is coincident with the oversized alternator then I may have to reconsider my position

Popping the breaker when turning the alternator OFF is just not right; something wacky is going on.  Low RPM suggests the load is being supplied by the battery rather than the alternator, which doesn't seem right, either (that was normal with generators at low RPM).  I wonder if you have a partial/intermittent short in the field circuit?  Check all the wiring.  I realize that's easier said than done.

Good luck!

[MB65E]

Replace the CB and send the VR to Don.

-Matt

[MB65E]

Some of the later Mooney’s had some strange inline fuses that drove me crazy one summer. 

-Matt

[dhawkes]

Hi, I have a 24 volt regulator from a M20K. If you still need one let me know.

Del

[Niko182]

Just now, dhawkes said:

Hi, I have a 24 volt regulator from a M20K. If you still need one let me know.

Del

How much do you want for it

[carusoam]

Make sure all the parts are matching...

including wire sizes... and CBs...

Expect that this was done when the oversized device was added..

If it wasn’t... that would be a different problem... or possibly the same problem...

 

So... the alternator CB trips when you switch the field off... ask @M20Doc...

sounds like there is induced current and some magnetism involved... to add to the complexity... ask the VR people as well...

PP thoughts only, not a mechanic.

Best regards,

-a-

[chriscalandro]

Could be a few things, the switch popping the breaker is interesting. That switch is what energizes the field from the battery. My first guess would be the switch being bad and grounding the circuit rather than opening it. 

 

An oversized alternator shouldn't matter. It's not going to create more current just because it's bigger, it just has the POTENTIAL to generate more current. The draw is the draw. 

[Ragsf15e]

On 9/1/2019 at 2:47 PM, Niko182 said:

Anyone know anywhere I can get it repaired ASAP. I have a check ride on the 12th and its quite inconveniant that it died right now.
I know maxwell fixes them But is there anywhere close to socal?

Not sure this helps, but a new digital Zeftronics VR from Spruce is a couple hundred $$ and in stock.  It’s a pretty easy switch and should last.

[Chris K]

Niko, wondering if you ever solved the issue and how?  I'm starting to get a slightly high voltage reading and have a feeling my VR is on its way out so wondering about part selection and results?  Thanks.

[Ragsf15e]

57 minutes ago, Chris K said:

Niko, wondering if you ever solved the issue and how?  I'm starting to get a slightly high voltage reading and have a feeling my VR is on its way out so wondering about part selection and results?  Thanks.

Curious, what’s “slightly high” and what kind of engine monitor are you using?

[Niko182]

1 hour ago, Chris K said:

Niko, wondering if you ever solved the issue and how?  I'm starting to get a slightly high voltage reading and have a feeling my VR is on its way out so wondering about part selection and results?  Thanks.

I figured it out by buying a voltage regulator for an encore. The awesome thing was that the encore voltage regulator has 2 of them since an encore has 2 alternators. I just opened the box and took 1 of the 2 regulators out, opened my regulator box, and switched it. Now i have a spare one if it goes out again. Another solution is to send it to maxwell. Takes about 5 days roundtrip and he charges 350 to fix them. A lot better than the 2.2amu mooney charhes for the regulator. If you have a basic understandic of eltronics and you know how to solder, it should be very easy to repair yourself. It has the quality of a playkit for a 13 year old learning electronics. My slightly high voltage reading was around 29.5 volts. When i switched it out, its now at 28.3v. The regulator i sent in to maxwell lasted about 8 months before it failed again. Nothing against maxwell. They just arent very high quality regulators.

[Niko182]

45 minutes ago, Ragsf15e said:

Curious, what’s “slightly high” and what kind of engine monitor are you using?

Slightly high was 29.3 to 29.5 volts and i have a jpi900.