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Another Plane Power failure

airguy

Unrepentant fanboy
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After reading all about the various issues with them, and humming along happily like I had good sense with mine, you guys all get your chance at "told ya so"...

Mine failed this morning at 720 hours, enroute of course, loud obnoxious whine in the headset and less than half the normal output. I could see the voltage drop and battery discharge when I pulled back on the RPM or added load, I was getting maybe (generously) 25 amps out of a 60 amp alternator.

B&C primary will be ordered tomorrow. I'm sure glad I installed a backup B&C, it took the load just like it always has and didn't care, kept soldiering on.
 
I have the same set up but haven’t flown yet. I’d be happy with 725 hrs. Do you have a blast tube on the alternators? I’m not planning to have them but curious what others have done.

Thanks
 
After reading all about the various issues with them, and humming along happily like I had good sense with mine, you guys all get your chance at "told ya so"...

Mine failed this morning at 720 hours, enroute of course, loud obnoxious whine in the headset and less than half the normal output. I could see the voltage drop and battery discharge when I pulled back on the RPM or added load, I was getting maybe (generously) 25 amps out of a 60 amp alternator.

B&C primary will be ordered tomorrow. I'm sure glad I installed a backup B&C, it took the load just like it always has and didn't care, kept soldiering on.

Likely the rectifier bridge, easily replaceable, but would only make a good backup. I will be happy with 720 hrs and plan for a replacement at 500 if it lasts that long. Since a B&C lasts twice as long as a good PP, the cost per hour is the same or less anyway. My 10-friend just replaced his at 500. We will take it apart and prepare it for a spare. He has a dual alternator system.

I did a complete teardown and report on a 520 hr PP, 60A that failed the rectifier bridge like yours. Everything else inside was good, bearings had good lube, even the brushes were only 25% worn to limit. Lots of life to go, just that one diode. A more robust diode bridge can be purchased in the aftermarket. 500 hrs is a good time to tear down and replace it. Clean interior and reuse the bearings, check brushes, and move on. The pulley bearing is available so it could be easily replaced, but the SRE bearing is special and not available outside Taiwan in quantities less than 5000.

Please take it apart and let me/us know if the slip ring end bearing has the expansion control rings on the OD of the outer race. That is the key to rebuildability as that bearing is not exported from Taiwan that I could find. Although, I got a quote directly from the NTN/Taiwan factory, although 5000/4999 is too many to have on hand. :eek:
IMG_4758.jpg
 
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And the difference is....?

Hopefully this question will result in some data being offered up.

Aside from the gold anodization, the B&C LX60 and PP AL12-EI60 look to be identical children of the same parent -- NipponDenso and Great-Big-Lucky-Industry-Factory #5. :)

I would love to understand B&C's engineering, supply chain, validation, testing, etc. that make their clone better than Hartzell's clone.

What're the differences, why are they different, what drove them to be different, how are those differences managed, validated and controlled.

Just asking before I drop $750 on another spinny-mechanical-thing...

Cheers!
 
I have the same set up but haven’t flown yet. I’d be happy with 725 hrs. Do you have a blast tube on the alternators? I’m not planning to have them but curious what others have done.

Thanks

PP requires a blast tube on the aft end of the alternator. Mine failed with < 300 hours. Replaced with externally regulated B&C. I think the externally regulated PP would also be fine but wasn't going to take another chance.
 
PP requires a blast tube on the aft end of the alternator. Mine failed with < 300 hours. Replaced with externally regulated B&C. I think the externally regulated PP would also be fine but wasn't going to take another chance.

That would definitely be part of my issue then - I did not install a blast tube on the Plane Power alternator. Still, it made it 720 hours.

I already ordered the B&C LX60 and external regulator this morning. Once and done.
 
I apologize if this was raised earlier, here, or in another thread, but I would like to see a correlation between Alt rpm at peak rpm and cruise and MTBF (mean time between failure).

Before I "woke up" I was going to install an alternator but found out that the pulleys I had available would spin the Alt over 9000 rpm at TO rpm of 2700.

Alternator output flattens out about 6000 rpm. I spoke to a guy over the phone and the data he provided gave 11,300 rpm for the alternator.

Short bearing life doesn't surprise me when they're spun that high.

Maybe a poll or equivalent?

FWIW
 
bigger pulley

I apologize if this was raised earlier, here, or in another thread, but I would like to see a correlation between Alt rpm at peak rpm and cruise and MTBF (mean time between failure).

Before I "woke up" I was going to install an alternator but found out that the pulleys I had available would spin the Alt over 9000 rpm at TO rpm of 2700.

Alternator output flattens out about 6000 rpm. I spoke to a guy over the phone and the data he provided gave 11,300 rpm for the alternator.

Short bearing life doesn't surprise me when they're spun that high.

Maybe a poll or equivalent?

FWIW
I installed a larger pulley on my alternator. No idea if it will make any real difference. https://www.summitracing.com/parts/PWM-185
 
I apologize if this was raised earlier, here, or in another thread, but I would like to see a correlation between Alt rpm at peak rpm and cruise and MTBF (mean time between failure).

Before I "woke up" I was going to install an alternator but found out that the pulleys I had available would spin the Alt over 9000 rpm at TO rpm of 2700.

Alternator output flattens out about 6000 rpm. I spoke to a guy over the phone and the data he provided gave 11,300 rpm for the alternator.

Short bearing life doesn't surprise me when they're spun that high.

Maybe a poll or equivalent?

FWIW

Most autos run a 2:1 pulley ratio, so the alternators spend most of their life around 5000-7000 RPM. However, those engines are red-lined at 6000 plus, so the alternators need to accommodate limited use around 12000 RPM.

I have the older generator flywheels with the smaller pulley and this gives me a nice ratio with the typical auto alternator pulleys. A larger pulley on the alt has the same effect.

Larry
 
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A larger pulley does seem like a good idea. In addition to a lower rotational speed, it should operate just fine with less belt tension.

So far, in 950 hours, I have failed one connector plug and one set of bearings. I'll stick with the PP for this airplane because I have both a whole unit and a spare regulator on the shelf, but lower bearing stress might head off an away-from-home failure. Down for annual in January....

The alternator on my old truck is somewhere north of 6000 hours without complaint. Serpentine flat belt, probably less tension (guessing, I've never measured one), plus the pulley sizes mean less RPM for most of the run time.
 
size

A larger pulley does seem like a good idea. In addition to a lower rotational speed, it should operate just fine with less belt tension.
...
Just watch cowl clearance. I installed the larger pulley before I finished my cowl.
 
Bearing problem is design or manufacturing defect.

I apologize if this was raised earlier, here, or in another thread, but I would like to see a correlation between Alt rpm at peak rpm and cruise and MTBF (mean time between failure).

Before I "woke up" I was going to install an alternator but found out that the pulleys I had available would spin the Alt over 9000 rpm at TO rpm of 2700.

Alternator output flattens out about 6000 rpm. I spoke to a guy over the phone and the data he provided gave 11,300 rpm for the alternator.

Short bearing life doesn't surprise me when they're spun that high.

Maybe a poll or equivalent?

FWIW
You can find spec sheets for the ND alternators that state the max rpm. I did the bearing calculations for the NTN bearings in the 60A PP from Vans. The life was more than 4000 hrs for the lubricant they use. I talked to the NTN bearing application engineer and she confirmed that was in the ball park for a 98% goal. The load are low, but the main difference in spinning a bearing is the hot clearance containing the races. One race has to float, the expansion rings on the PP (shown above) are what allow that race to float axially but have enough friction retention to prevent orbit or spinning of the race due to rotating friction. It is a precise design balance between the two with a wide window when done correctly. They type of bearing seals makes a big difference on the rotating friction. Rotor imbalance would have a huge effect on bearings and structure of the 60A PP alternator.

I have yet to ascertain whether the bearing shown above has remain in continuous use by PP since the Hartzell acquisition.
 
On the 2 to 1 pulley ratio.

Showing I'm an old fart, I recall the advent of Alts in automobiles. Powered accessories were increasing. The major benefit touted was charge output at idle rpm (generators had virtually none at idle).

Engines of that era generally ran at rpm ranges that wouldn't see the Alt spinning too fast - even at freeway speeds.

I see no good reason to spin an alternator above its productive RPM range.

FWIW
 
Just watch cowl clearance. I installed the larger pulley before I finished my cowl.

This! I have unintentionally cut grooves in cowlings with the alternator pulley, so the larger you go, the more you might need a blister.

Dan, you can calculate the drag increase from the blister....;)

Paul
 
On the 2 to 1 pulley ratio.

Showing I'm an old fart, I recall the advent of Alts in automobiles. Powered accessories were increasing. The major benefit touted was charge output at idle rpm (generators had virtually none at idle).

Engines of that era generally ran at rpm ranges that wouldn't see the Alt spinning too fast - even at freeway speeds.

I see no good reason to spin an alternator above its productive RPM range.

FWIW

The key is managing the RPM range within the output slope . On my 6, the alt pulley is a bit too big and when i pull the power coming over the fence, with all the lights on, I get an annoying low voltage warning. At idle, the alt isn't spinning fast enough to meet the current draw in that configuration. There is a limit on the pulley ratio.

Larry
 
Since a B&C lasts twice as long as a good PP, the cost per hour is the same or less anyway. My 10-friend just replaced his at 500. We will take it apart and prepare it for a spare. He has a dual alternator system.

The rectifier bridge is inside the alternator (and exposed to heat) on both B&C and PlanePower alternators. It likely has the same probability of failing on both. I attribute the bridge failure to my LiFePo4 battery's hunger for juice at startup. Two bridge failures, actually within about 100 hours.

Just putting that out there before people conclude that B&C is twice better...

The B&C has two good things going for it from an electrical standpoint. They isolated the regulator from heat, and also removed the field switch and breaker from the voltage sense circuit.

Mechanically, their brackets are a mess. Between a friend and I we have 3 different engines (narrow deck IO-540, IO-390 and angle valve IO-540) on which none of brackets fit properly, leaving the belt misaligned. They promised to make better brackets but that never happened.
 
The rectifier bridge is inside the alternator (and exposed to heat) on both B&C and PlanePower alternators. It likely has the same probability of failing on both. I attribute the bridge failure to my LiFePo4 battery's hunger for juice at startup. Two bridge failures, actually within about 100 hours.

Now that's a very real possibility there - the lithium batteries will have the alternator running at max capacity for the first couple minutes after start, heating and stressing the rectifiers. I know that I see recharge rates right after start (900-1000 rpm, letting the engine warm) in the 30-35 amp range. That's not out of the alternator, that's into my battery after handling all panel loads which are about 20 amps sitting there. So the alternator is going to be putting out 50+ amps out of a 60 amp rating. It should do it, certainly - but how many times and for how many hours?
 
I used to see 60+ amps out of the alternator after startup for a few seconds.
I ended up getting a 30amp vacuum pad mounted standby alternator. After starting with the lithium battery it would engage the standby too at around 15 amps.
Them lithiums are hungry... :)

Lenny


Now that's a very real possibility there - the lithium batteries will have the alternator running at max capacity for the first couple minutes after start, heating and stressing the rectifiers. I know that I see recharge rates right after start (900-1000 rpm, letting the engine warm) in the 30-35 amp range. That's not out of the alternator, that's into my battery after handling all panel loads which are about 20 amps sitting there. So the alternator is going to be putting out 50+ amps out of a 60 amp rating. It should do it, certainly - but how many times and for how many hours?
 
I used to see 60+ amps out of the alternator after startup for a few seconds.
I ended up getting a 30amp vacuum pad mounted standby alternator. After starting with the lithium battery it would engage the standby too at around 15 amps.
Them lithiums are hungry... :)

Lenny

Yep, I keep my standby vacuum pad alternator offline until the recharge surge is past.
 
I sure hope the B&C alternator works better than the B&C ordering and shipping department.

I called first thing Thursday morning last week, to order my alternator and make sure I got the brackets right. Spoke with one of the techs by the name of TJ, got the right thing selected and he set up the order, gave him a credit card number, the whole bit. He said he would email confirmation and shipping details.

Now, Monday morning - still no email, and no charge to the credit card. I called them and spoke with Jenny, and she tells me "Yeah, it takes a while, but it should ship out today, I think."

Color me unimpressed with the level of customer service displayed here. The product better be good, because the sales experience was not.
 
LiFePo4 battery

I installed a LiFePo4 680 for about 25 hours, but removed it because after every engine start, the alternator was putting out 30 - 55 amps for 15 to 30 seconds until the battery was fully recharged. The 60 amp current limiter in my system was charred brown after six engine starts / max alternator charge output cycles.

Not faulting the LiFePo4 battery itself.


One has to think that continuous cyclic exposure to max amp output of 30-55 amps at 1000-1200 rpm after every engine start is going to be hard on the wiring and alternator, no matter which brand.

I have both B&C and PP.
 
I installed a LiFePo4 680 for about 25 hours, but removed it because after every engine start, the alternator was putting out 30 - 55 amps for 15 to 30 seconds until the battery was fully recharged. The 60 amp current limiter in my system was charred brown after six engine starts / max alternator charge output cycles.

One has to think that continuous cyclic exposure to max amp output of 30-55 amps at 1000-1200 rpm after every engine start is going to be hard on the wiring and alternator, no matter which brand.

IIRC 60amp output is supposed to be continuous duty cycle, wiring an all connected components should match. Should be just fine running 60amps all the time, right? I mean, I didn't buy a 40amp alternator with 60amp burst for short periods ... it just says 60amps
 
It is 60 continuous duty on the bench. According to the Hartzell chart that came with my alternator it makes more than 60A on the bench.

The rectifier diodes generate their own heat depending on the load and then don't forget that the alternator is placed a few inches from a 1300F exhaust pipe. No problem in flight, but on runup, when charge demand is high and airflow is minimal the alternator can get hot. Not sure if a blast tube would help with that.
 
IIRC 60amp output is supposed to be continuous duty cycle, wiring an all connected components should match. Should be just fine running 60amps all the time, right? I mean, I didn't buy a 40amp alternator with 60amp burst for short periods ... it just says 60amps

Do you run your engine at max power all the time because that's what its rated at?
About the same thing, yes it will do it, but the life of the unit will be shorter.
I prefer to de-rate alt and engine continuous output to about 70% for a longer life.
 
B&C is twice the life according to the data presented here.

The rectifier bridge is inside the alternator (and exposed to heat) on both B&C and PlanePower alternators. It likely has the same probability of failing on both. I attribute the bridge failure to my LiFePo4 battery's hunger for juice at startup. Two bridge failures, actually within about 100 hours.

Just putting that out there before people conclude that B&C is twice better...

You have lots of assumptions there.

The data presented over the years and plotted on a Weibull chart shows that the B&C is twice better for life. Even if we edit out the early hour failures they had some years ago due to a manufacturing issue.

All rectifiers in the bridges are not equal in durability. Researching aftermarket parts revealed there are heavy duty bridges offered at a premium price that have less heat generation and a higher abuse test rating. They are special orders from the manufacturer per their catalogue. Since the B&C is a new/modified Denso, they would know the abuse tolerance of their products and spend the extra $.01 as it would reduce warranty. Did you know aftermarket catalytic converters have half the precious metal as the new one?

920 hrs is pretty good for the PP 60a experimental alternator.
 
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I can’t put my finger on it but someone did a teardown comparison of the two 60A alternators. IIRC, the conclusion was that the B&C was a modified genuine DENSO and the PP unit was an aftermarket (Unipoint?) version of a similar DENSO unit. PP modified theirs to include an over voltage shutdown, whereas B&C modified theirs for external regulation. Really wish I could find that on the internet, it was a thorough writeup.

FWIW, I have a PP internally regulated unit installed on my 0-360 RV6A. At about 300 hrs TT on the alternator, I converted the engine from carb to FI. As a part of that I removed the carb heat muff, which provided shielding for the back of the alternator and failed to replace with a shield. Within 10 hrs alternator had large variances in the voltage output. I pulled the alternator, replaced the brush block/regulator and reinstalled. Added a shield on the exhaust. No problems since.
 
My hangar mate had his PP take a dump after 140 hours. He had it repaired at one of the local shops although he also bought a replacement from Van’s which is what he ended up installing, keeping the former unit as a backup. He upped the size of his blast tube hoping to prevent a similar problem from recurring. I’m kinda glad that I went B&C although I guess time will tell.
 
Here's a question that I have, and there may be only a couple guys that actually know the answer - how do the temperature environments compare between under-cowl and under-hood for automotive? Are we really significantly hotter than an automotive application?
 
Me thinks

I wonder if it is not just the surrounding air temperature, but the idea that the alternator is seeing the white hot exhaust pipes or not.
 
B&C, 865 hrs. no issues.

the only things I have replaced in 865 hrs outside of normal maint items (tires, brakes, battery, mag service, prop service) is a flap motor, a hall effect sensor and front crank seal. that's it.
 
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I wonder if it is not just the surrounding air temperature, but the idea that the alternator is seeing the white hot exhaust pipes or not.

There are 2 main external heat sources for the alternator. The air coming through the cylinders which is heated therefore conducting heat to the alternator and the radiated heat from the exhaust pipes which is direcly related to the distance from the pipe. I do not have objetive data as to which is key, but I believe that the radiated heat can far exceed the conducted heat. In a car, there is very limited radiated heat (exposure to exhaust components) whereas, I think that it is a significant factor in our installations. The key advantage that B&C has over the internally regulated PP alternator is that the regulator electronics is located in a cooler environment.
 
Here's a question that I have, and there may be only a couple guys that actually know the answer - how do the temperature environments compare between under-cowl and under-hood for automotive? Are we really significantly hotter than an automotive application?

I don't think we are hotter than automotive. The underwood electronics standard is 130C tolerance, that is 266F. DanH measured 230f, but I have not seen over 200F on my 7. The thermocouple is located up high near my GPS antenna.

A car will go slow, has 230F coolant temperatures, and runs air conditioners. Time weighted average may be another matter.
 
PP

On my new 7 with IO390 and EarthX battery, PP alternator, I had a problem with the Alt Field. One start it would come on and the battery would charge. The next start it wouldn't. I spoke with Alan at PP and he advised to check the connector.

I ultimately potted in a layer of E6000 adhesive in the recess of the connector where the wires are snapped into their receptacles. I have not had a problem since. This seems to be where many of the problems occur.

I should note that most of my 40 hour fly off occurred during May to July in AZ. We had the hottest summer on record. I don't believe the airplane environment is any hotter than that of a car. I have no blast tubes.

On a side note, it can take several minutes for the charge rate to drop with the EarthX. I'm not concerned as it has been consistent.
 
I sure hope the B&C alternator works better than the B&C ordering and shipping department.

I called first thing Thursday morning last week, to order my alternator and make sure I got the brackets right. Spoke with one of the techs by the name of TJ, got the right thing selected and he set up the order, gave him a credit card number, the whole bit. He said he would email confirmation and shipping details.

Now, Monday morning - still no email, and no charge to the credit card. I called them and spoke with Jenny, and she tells me "Yeah, it takes a while, but it should ship out today, I think."

Color me unimpressed with the level of customer service displayed here. The product better be good, because the sales experience was not.

Hmmm... I may have to go back on with another Plane Power alternator after all. After the above, I called again this afternoon (during their business hours) and nobody answered the phone at any extension. I left a message for the tech that I spoke with last week - but I still have no order confirmation or shipment notification.

This is NOT acceptable customer service. I'm going to call again in the morning, and if it's not already on a truck with a tracking number to show it, I will cancel the order and go back with a PP alternator. This level of customer service is BS.
 
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Greg-

Low numbers here, but I'll counter your N of 1 with my N of 2 (plus a couple other calls to chat about install / mounting, etc).

I ordered the backup alt for my -10 during the upgrade, easy process and it shipped quickly from B&C.

When my PP primary alt died the 2nd time, I ordered a B&C replacement - it also shipped quickly, no issues.

I called them a couple times to discuss questions and always got a real live (knowledgeable) person on the phone.

Maybe there is something going on, who knows with all the COVID stuff, etc. I've been very happy with B&C.

Thomas
 
I replaced my PP alternator with a B&C two months ago. B&C was very professional and made it easy to complete my order. The parts were all correct and were shipped when expected. The install instructions were complete. Follow up questions were answered on the phone. The alternator has been operating flawlessly. I would have no issues doing business with them again.
 
Another data point

My 2010 vintage 60 amp PP alternator failed a few months ago at about 920 hours. Blast tube installed since new. Regularly checked condition of connector including removing/contact cleaner spray since otherwise voltage would drop off, as described in a thread started by Dan Horton. Likewise regularly checked belt tension per Lycoming service instruction. Symptoms at failure were fluctuating voltage and whining in headset.

Ordered a replacement from B&C. I was notified that there could be a shipping delay. I had a trip planned with my RV-7 that would have been impacted. I figured I had nothing to lose by calling and asking if they could expedite shipping, so I did. Not only did they expedite shipping, they were super nice about it. Had a similar experience when ordering a backup alternator a few years ago. Very pleased with B&C service.
 
Turns out the original delay was the only one - the alternator and regulator shipped on Monday, they had my email incorrect to send me the confirmation and tracking data. UPS has it out for delivery to me today.
 
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