Voltage Regulator Failures

[Daviator]

Anyone had voltage regulator failures on their Jab 3300? I have had two fail on me in less that 2 hours of flight time and before I risk another one I would like to know if this could possibly be an indication of something else wrong. The original regulator was on the plane for over 250 hours of flight but the second one went bad after only about an hour. I've checked my wiring several times and had a knowledgeable friend look at it also but we can't see anything wrong.

[pepperdoug]

My original lasted (sorry, going by memory here as I just sold my plane) about 250 hours. My second less than 15 hours. My third is still in service after another 200 hours.
The second was replaced without charge. Funny thing was I ordered another one (generic and a lot cheaper) off the Internet as a spare and installed it before the warranty replacement came. So now, I have a good one sitting around with no airplane.
Also, the first failure was catastrophic. While on a short flight I smelled something electrical. I shut down the Master and landed within 15 minutes. The failed unit had burned a small hole in my firewall where it is mounted. That was interesting! The back of the unit was melted and looked as if it shorted itself out internally.
The second unit failed but just quit working.
As a side note…and this is purely subjective and unsubstantiated or documented…I had noticed odd behavior in my EIS system, such as odd outside air temps and fluctuating EGT temps for a long time before eventual voltage reg failure. Since these symptoms disappeared after replacement, I assume it was the regulator causing the odd instrument behavior.

[fastj22]

Interesting symptoms. I was experiencing some erratic readings on my senders too and they magically stabilized recently. I wonder if my regulator is blinking out on me. Might be a good time to order a spare and have it ready to swap. I found the Kubota replacement on Amazon for $28.

[ldmill]

My first thought on this is that you may have an intermittent grounding or power issue. Most EFIS and radio's are able to ride through short moments of loss of power (10-50 milli-seconds) and voltage surges without a restart - so you have no specific visual indicator of momentary power loss. However, cycling power like this will eventually lead to issues somewhere due to the voltage spikes that accompany it. My suggestion would be to start looking at ground/power cables & wires and make sure they are clean.

My own experience on this cost me a pocket full of greenbacks. My Jeep blew multiple expensive electrical thingies over a short period of time before we finally traced it back to a ground cable connection at the battery that was slightly loose and moderately corroded.

Lorin Miller

[DCASonex]

Suspect you have a problem somewhere, Have a bit over 200 hours on mine (combined total with Jabiru and CAMit engines). Do have a cooling air jet directed at it, and it is mounted on a SS plate raised about 1/4" from FW in case it decides to burn up. Cooling fins are oriented vertical for best air flow. I pop off the cowl's oil filler cover to let out heat on landing. Had stablemate for a while with same 3300 and and his only lasted 5 hours. ??? If you have not already done so, replace those undersized spade lug connectors that came on the alternator. Any GOOD quality ones of same size will suffice. Poor connections can cause untold problems, not just burned wires and lack of charging.

David A.

[Daviator]

Update on the Voltage Regulator:

Executive summary - Don't buy cheap Chinese made regulators, stick with the Kubota brand, made in Japan, original equipment. If you want more detail keep reading.

I decided to replace my voltage regulator after I noticed the peak voltage while the engine was running was starting to creep up to voltages that I thought were not safe for operation. Turns out that the Odyssey PC625 battery has a voltage rating of 14.7 volts when charging and can even go as high as 14.8. This was my first mistake that started a domino effect of failures. I purchased a voltage regulator online for a price that was significantly less than what I was quoted by Jabiru USA. I installed this voltage regulator and flew for approximately 30 hours before I noticed that the battery was not able to crank the engine on a cold start up like it had done previously. I purchased a trickle charger and the problem seem to have disappeared, the weather was getting warmer and the charger kept the battery well maintained. After about another 10 hours the new voltage regulator quit working. Now I started to suspect an alternator problem and so i purchased and installed another regulator. This regulator (#3) quit after only about an hour of flight. Now I started to dig into things much deeper, investigating the battery specifications, regulator specification, and alternator specifications which included a conversation with Pete at Jabiru USA. I came to the conclusion that the problem was most likely the aftermarket regulators that I had been using. I have now installed an original Kubota RP201-53710 regulator and my problems (perceived or true) have gone away.

Things to remember:
1. Seeing 14.7 volts while the engine is running is acceptable for the Odyssey PC625 battery
2. The Jabiru 3300 alternator is rated at 20 amps but has a peek output of 32 amps
3. Get educated on the specifications of the parts you are replacing before replacing them.

[Boat]

I thought I had a problem with my new Jabiru 2200 engine regulator. Turned out it was a loose solder joint on the alternator stator. You can go to the Jabiru sight and get the Engineering Report for the Mod they made. Strange that my engine was new 11/15 but had a factory mod from 2013 on it.

Jabiru NA sent me a new alternator stator and it seems all the stators for the last few years are supposed to be 3300 alternator stators with a single wire winding and putting out 20 amps

AVDALSR087-1_12_Pole_Alternator_Mod.pdf

[sonex1374]

I've been having intermittent problems with my Jabiru 3300 voltage regulator (the stock Kubota model, PN RP201-53710). Over the past 30 hours or so I've had times where the regulator didn't seem to produce enough charging voltage, and times where it raised up to unacceptably high levels. To give you an idea of the variability I saw, regulator output on the low end was below 12.0 volts, even at high rpm, and on the high end was over 15.0 volts (when the over-voltage protection circuit would disconnect the alternator). Clearly something was wrong.

I conducted some initial troubleshooting, including verifying the voltages I was seeing on my Skyview matched an independent volt meter reading, and inspected all the connections and wiring from the alternator (AC stator) wires and the voltage regulator connectors. Nothing obvious was found, but each time I fiddled with things the problem seemed to go away for a short time, ultimately to reappear.

Searching on the VAF site, some of the RV-12 guys reported good success swapping the stock Rotax 912 regulator for a replacement unit. This unit is similar to the Kubota model, but has a higher output voltage (approx. 14.5 volts, vs. approx. 13.9 for the Kubota regulator). I recently swapped out my old Kubota regulator for the new model and have been flying it with good results. The output voltage has been stable, and the battery seems to charge well. In fact, even at low rpm I see higher voltage output that the old regulator, and the battery must like that.

The new unit looks very similar, and has the same bolt mounting pattern as the Kubota, but features fast-on male terminals rather than wires and a pigtail+OEM connector like the Kubota. The new one uses a case ground, but the rest of the connections are similar (the Kubota "ignition" (AKA voltage sense) wire is labeled "IGW" on the new one).

I use a "Caltric model R11-2, PN LD1293111RV", but it's listed as a replacement for the "John Deere Mower F915, AM101406". There are others that look identical on Amazon and Ebay, and I have now idea if one brand is better than another. All I can say is mine is working well so far, and I'll report again after 50 hours, or if problems resurface.

https://www.amazon.com/Caltric-Regulato ... B008HTBHUI

https://www.ebay.com/itm/Regulator-Rect ... 2749.l2649

s-l500b.jpg (33.06 KiB) Viewed 12670 times

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edit August 2019: follow-up posted at:
viewtopic.php?f=8&t=5076
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Jeff

[daleandee]

Executive summary - Don't buy cheap Chinese made regulators, stick with the Kubota brand, made in Japan, original equipment. If you want more detail keep reading.

Things to remember:
1. Seeing 14.7 volts while the engine is running is acceptable for the Odyssey PC625 battery.

Good post! While my Cleanex uses a Corvair engine the power is supplied by a permanent magnet alternator i.e. a "dynamo." The called for regulator is the one used with it on the John Deere equipment that it was designed for. They are made in Japan, are a bit expensive, and work like they're supposed to. I went through the cheap regulator phase and realized that saving money by purchasing junk regulators for an aircraft that is electrically dependent was not a route that I wanted to continue on. Seems to me I paid about ninety bucks for the regulator I got but it has been flawless since. The cheap one I bought regulated voltage too low, had stuff that would seep out of it (the manufacturer said that was normal), and the over voltage light would flicker at idle and get brighter with more throttle.

I use the Odyssey PC-680 and read that charging is at 14.7 - 14.8 VDC and should not exceed 15.0. Charging an Odyssey battery with too little voltage will eventually damage it. I used my first PC-680 for two years and, although it was still working as good as new, I replaced it as I didn't want to get caught somewhere with a low battery. It sat on the shelf in my shop for another two years with out any thing attached to it. I pulled out the four year old battery, put it in the lawn tractor, and it cranked right up!

I haven't found the need to use a trickle charger on an Odyssey battery that gets flown and properly charged now and again. Some builders desire to save money with cheaper batteries and regulators and that's fine. There's nothing wrong with inexpensive items ... provided they work up to the standard that is required. The builder is the one that sets the standard for what is acceptable to them.

Dale Williams
N319WF @ 6J2
Myunn - "daughter of Cleanex"
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
Signature Finish 2200 Paint Job
161.6 hours / Status - Flying
Member # 109 - Florida Sonex Association

[rizzz]

Executive summary - Don't buy cheap Chinese made regulators, stick with the Kubota brand, made in Japan, original equipment. If you want more detail keep reading.

Not only Chinese regulators are known to be of lower quality.
I had a Harley Davidson brand 20amp Alternator & Voltage regulator on my custom VW conversion.
The regulator broke after less than a year of service.
Talking to some experienced bike builders I was advised to stay away from the original Harley Davidson brand electrical stuff and go with aftermarket Japanese copies, they seem to survive much longer. So that's what I did, my new regulator is holding up so far, I still have the original HD alternator installed but have my Japanese copy ready as well for when it breaks.