Auto Alternators

[Lars]

Originally Posted by rocketbob

I have used these alternators to replace Plane Power alternators. They have been 100% reliable.

The spec sheet that comes with these show output above 60A.

As far as brackets go I have fabricated them and I have also modified the Plane Power bracket with a simple bushing turned on my lathe. I've also used the boss mount alternator brackets Van's used to sell but I can no longer find them on their site.

Worth mentioning I've never used a blast tube.

Regarding using one of these to replace a PP alternator... I have a lathe and can likely figure out mechanical mounting details, but curious about what else is required for the swap. PP alternators have overvoltage protection built in, or so they say. Did you address that or that built in to these? What about the belt? As regards the latter it would be swell if the same belt could be used since I'm lazy and don't feel like pulling my constant speed prop, but I'd do so if that's what has to happen (or perhaps a pulley swap and obviate the effort). My PP is once again showing less than optimal voltage, probably once again due to the flakey connector. This alternator appears to have 1/4" spade terminals which I'm guessing will stay put a bit better. PP (Hartzell) doesn't even offer the alternator I have anymore; for what a replacement costs I could fill all the remaining shelf space in my hangar with these as spares..

[rapid_ascent]

Anyone know about the mounting of the Denso or in my case Bosch AL257X? Which brackets will fit? Any pictures of your mounting brackets and etc. I?m afraid I?m not in the weld up a bracket camp.

[gmcjetpilot]

Originally Posted by rv6ejguy

Depends on the alternator and we've had this discussion before. Many IR Denso alternators have 2 or 3 terminals. Take 12V off one external control terminal (usually marked IG) and charging stops:

https://www.youtube.com/watch?v=NvQRHuNpjss

Darn you and your facts and demonstrations and irrefutable evidence... Ha ha.

To be fair the IGN is not "direct" field power. It is through semil-conductor (transistor) that may indeed kill the field, but it's not providing field juice through the IGN lead. IGN is a sense lead. The drain on the IGN lead is tiny when it is running. Like most "one-wire" alternators the field power comes from the B-lead.

Many so called "ND" Alternators are not original ND but China knockoffs or "clones". The internal VR in the clones don't seem to be standard. Quality and reliability also seems to vary. Not all of them work the same in regards to the IGN lead (so I have been told and heard). One guy cycled his "IGN" off then on in flight and got a massive OV.... My ND is only 40-45 amps. The B-lead is going through a panel mounted 50 AMP Circuit breaker. The avionics bus is parallel feed with two OV relays. I recommend finding a genuine new ND. Cheers.

[rocketbob]

Originally Posted by Lars

Regarding using one of these to replace a PP alternator... I have a lathe and can likely figure out mechanical mounting details, but curious about what else is required for the swap. PP alternators have overvoltage protection built in, or so they say. Did you address that or that built in to these? What about the belt? As regards the latter it would be swell if the same belt could be used since I'm lazy and don't feel like pulling my constant speed prop, but I'd do so if that's what has to happen (or perhaps a pulley swap and obviate the effort). My PP is once again showing less than optimal voltage, probably once again due to the flakey connector. This alternator appears to have 1/4" spade terminals which I'm guessing will stay put a bit better. PP (Hartzell) doesn't even offer the alternator I have anymore; for what a replacement costs I could fill all the remaining shelf space in my hangar with these as spares..

They all have OVP built in. Supposedly. Have I verified it? No. Have I had an OV happen? Yes, on an old alternator. Haven't worried about it up to this point as all of them I've installed are not on electrically-dependent airplanes. There are many ways to skin this cat with off-the-shelf components. My rocket requires this and I have a circuit I have in mind but have not built the device yet.


I've used the same belt the PP alternator used.

[rv6ejguy]

Originally Posted by gmcjetpilot

Darn you and your facts and demonstrations and irrefutable evidence... Ha ha.

To be fair the IGN is not "direct" field power. It is through semil-conductor (transistor) that may indeed kill the field, but it's not providing field juice through the IGN lead. IGN is a sense lead. The drain on the IGN lead is tiny when it is running. Like most "one-wire" alternators the field power comes from the B-lead.

Many so called "ND" Alternators are not original ND but China knockoffs or "clones". The internal VR in the clones don't seem to be standard. Quality and reliability also seems to vary. Not all of them work the same in regards to the IGN lead (so I have been told and heard). One guy cycled his "IGN" off then on in flight and got a massive OV.... My ND is only 40-45 amps. The B-lead is going through a panel mounted 50 AMP Circuit breaker. The avionics bus is parallel feed with two OV relays. I recommend finding a genuine new ND. Cheers.

Yes, we've had extensive discussions in other threads on bad Denso clones and OEM Densos having their OEM reliability compromised by rebuilding shops inserting inferior, non-Denso regulators, brushes and bearings, which is super common unfortunately.

I recommend using the older 3 terminal (4 with B lead) Denso units.

You can watch a bench test on a one wire unit here. Removing the "field wire" stops the charging. https://www.youtube.com/watch?v=LFscQAbk5ao

[WingsOnWheels]

I am running an auto alternator. For OV protection I have a relay on the B lead. The relay energizes with the master. There is a crowbar OV module in the relay coil circuit, so if I get and overvolt, the crowbar will trip the breaker for the relay and disconnect the alternator from the system.

[Lars]

Originally Posted by rocketbob

They all have OVP built in. Supposedly. Have I verified it? No. Have I had an OV happen? Yes, on an old alternator. Haven't worried about it up to this point as all of them I've installed are not on electrically-dependent airplanes. There are many ways to skin this cat with off-the-shelf components. My rocket requires this and I have a circuit I have in mind but have not built the device yet.


I've used the same belt the PP alternator used.

Thanks for the info. I've witnessed two PP alternator failures (both were pre-Hartzell models, as is mine), neither in my airplane fortunately. Not a connector getting flakey, something going TU and tripping the field circuit breaker. OV protection worked in both cases on those units.

[1flyingyogi]

My alternator went bad shortly after I bought the plane 3 years ago and I went with a Duralast alternator from Autozone and couldn't be happier. Mine is a 30amp alternator. I know you're looking for a 50amp, but I'm just chiming in to say that I'm very happy with it so far.

It's paired with a Duralast voltage regulator (model number VR730) and both have lifetime warranties, and cost almost nothing compared to aviation alternators. The alternator was about $45, voltage regulator about $20.

Reliable, cheap, lifetime warranty, and almost drop in replacement (had to change the pulley - I used the one off my old alternator).

[Caveman]

My first Plane Power alternator lasted around 240 hours. It quit leaving Oshkosh several years ago. I started getting low amperage alarms on my second Plane Power just before landing at We B Smoking on the way home from Oshkosh this year. This alternator had around 510 hours on it. I bought an '87 Suzuki Samurai alternator to replace it with but it wouldn't fit my mount. So, I shelled out the big $$$ and installed a B&C and their external voltage regulator. Of course, I had to pull the constant speed prop for the new belt, (old one was eleven years old but was still in good shape with no cracks or fraying) and crawl under the panel to install the regulator. Not much fun for an old guy when it is 95 degrees out. Hopefully, I'm good to go for a long time.

My PP failure modes were completely different. The first one lost the rear bearing. It appears the second one toasted the regulator. The bearings are smooth. No issues with the connector. I tried them with and without blast tubes. Both were pre-Hartzell units.

It seems some guys are slapping the Samurai alt. on the PP mount and not even having to change the connector. It wasn't even close to lining up the pulleys for me...

[bobnoffs]

i have never heard of an auto having its glass panel taken out by ov but i installed one similiar to colin's. my relay on the b lead is disconnected by a domino sized unit sold by perihelion, eliminating the breaker on the coil of the relay.i also have the 50 amp breaker on the panel but like another has said pulling that may fry the alternator.