Alternator woes

Rick6a · #1 10-16-2006, 11:01 AM

After only 175 Hobbs hours or so, 60 amp internally regulated alternator from Van's suddenly shot craps. In fact, it probably hasn't functioned 100% since day one because of another nagging issue that I won't go into here. It is cooled with a blast tube. In any event, while flying yesterday, the audio alarm went off on the VM-1000 engine monitor indicating a total loss of amps. My RV sports no overvoltage protection device that Van's cautions against when using this particular alternator. There is no denying the cost advantage of buying such an economical alternator, but I really don't want to replace it every few hundred hours or so. A bit of casual research seems to reveal that some RV'ers experience relatively early failure using the rebuilt automotive type alternators that Van's stocks. With no vacuum system installed, I tend to put a premium on maximum reliability. Any cogent thoughts from those who have gone through this on a better choice of alternator to replace it with?

kevinh · #2 10-16-2006, 11:26 AM

Quote:

Originally Posted by Rick6a

After only 175 Hobbs hours or so, 60 amp internally regulated alternator from Van's suddenly shot craps. In fact, it probably hasn't functioned 100% since day one because of another nagging issue that I won't go into here. It is cooled with a blast tube. In any event, while flying yesterday, the audio alarm went off on the VM-1000 engine monitor indicating a total loss of amps. My RV sports no overvoltage protection device that Van's cautions against when using this particular alternator. There is no denying the cost advantage of buying such an economical alternator, but I really don't want to replace it every few hundred hours or so. A bit of casual research seems to reveal that some RV'ers experience relatively early failure using the rebuilt automotive type alternators that Van's stocks. With no vacuum system installed, I tend to put a premium on maximum reliability. Any cogent thoughts from those who have gone through this on a better choice of alternator to replace it with?

After replacing this alternator twice (once while in the middle of _nowhere_), I've switched to the plane power alt. Hopefully it will be more reliable... So far after 40ish hours, running great and keeps putting out 14.1 even under high load - something that the van's alternator wouldn't do sometimes when hot.

I agree, a few hundred dollars more expensive but I really hate having my alternator fail at random.

f1rocket · #3 10-16-2006, 02:05 PM

If maximum reliability is your criteria, spend the money for a B&C alternator and alternator controller. It will go to engine TBO.

Chickenlips · #4 10-16-2006, 03:35 PM

The 60 amp unit from Van's is simply an automotive alternator and can be rebuilt at any automobile alternator repair shop.

One of three things I know of that may stress the unit and shorten its life is the heavy vibration in that area. The nose of some engines can have so much vibration that it damages the alternator. One thing that really helps to prevent vibration damage is the link that is supplied in the alternator bracket kit that joins the alternator forward mounting bolt to the starter case. This link can really help to reduce vibration damage. Both to the starter as well as the engine case.

The second issue is "excess" power consumption. The actual continuous duty cycle for this style alternator is only about 60% of rating and so if your flying regularly with current draws in excess of 36 amps, then you are possibly overloading it.

The third thing that is absolutely not a good idea is to regularly "test" the alternator circuit while the engine is running. Absolutely NEVER pull the breaker on the output (battery charging) side of the alternator. Opening this circuit while the unit is charging will destroy it immediately. In addition, even opening the "sense" lead from the aircraft buss to the "sense" terminal on the alternator is not good for it either though most will tolerate a certain amount of this abuse.

David-aviator · #5 10-16-2006, 03:57 PM

Quote:

Originally Posted by Rick6a

After only 175 Hobbs hours or so, 60 amp internally regulated alternator from Van's suddenly shot craps. ....Any cogent thoughts from those who have gone through this on a better choice of alternator to replace it with?

Rick,
I've had very good service with B&C (on the Cozy). That alternator is about 7 years in service. B&C makes the housing to fit Lycoming, but I believe the guts of the unit is a modified Nippon Denso.

All the Egg Subaru engines come through with the Nippon Denso auto version with internal regulation and so far there have been no reported failures. They are a tough little alternator.

dd

gmcjetpilot · #6 10-16-2006, 04:27 PM

Quote:

Originally Posted by Rick6a

After only 175 Hobbs hours or so, 60 amp internally regulated alternator from Van's suddenly shot craps. In fact, it probably hasn't functioned 100% since day one because of another nagging issue that I won't go into here. It is cooled with a blast tube. In any event, while flying yesterday, the audio alarm went off on the VM-1000 engine monitor indicating a total loss of amps. My RV sports no overvoltage protection device that Van's cautions against when using this particular alternator.
[Note there was no overvoltage, correct, lets not feed that rumor mill]

There is no denying the cost advantage of buying such an economical alternator, but I really don't want to replace it every few hundred hours or so. A bit of casual research seems to reveal that some RV'ers experience relatively early failure using the rebuilt automotive type alternators that Van's stocks. With no vacuum system installed, I tend to put a premium on maximum reliability. Any cogent thoughts from those who have gone through this on a better choice of alternator to replace it with?

I have followed this saga very closely. I have no solid evidence other than casually tracking problems with this model in particular sold by Van's aircraft. I do think Van's had a Vendor problem and was getting alternators made with poor quality "after market" components. Although Van may dispute it, I respectfully disagree with them.

These alternators are NOT real Nippondenso, but Chinese knock offs. There are good Chinese aftermarket parts and not so good parts. I know because I looked into importing them. There are about 3 main players (many more smaller ones) making parts for this model. Keep in mind this alternator has not been in production by ND, the OEM, for well over 10 years, so after market parts are normal. The point is they are not all the same.

Well I was looking into getting into the alternator business for experimentals myself for fun a profit; I thought I could do better than Van's and B&C (ridiculous prices). However, frankly since Plane Power came along, I abandoned that idea because he did everything I was thinking and more. I have talked to him and he is doing everything right and made some nice mods. He starts with the better new after market parts, uses a CCW fan (B&C does not even do that) and high altitude brushes. The stock brushes in ND's can wear faster at altitude due to low humidity. Its not a big deal but a nice touch. Plus PP adds a nice secondary over-voltage module on top of the unit, which cuts power off to the VR and field. [The OV method Bob Nuckols of Aeroelectrics suggest is a "Shorting Device" or "Crow Bar", which means you actually short out a circuit breaker (CB) to trip it, thus removing the power to a relay, opening the B-lead. This is a bit Rube Goldberg and can and does damage a good alternator if it accidentally trips.]

Bottom line your idea of going with Plane Power sounds like a good one. Buy the whole kit and install it. Take your old brackets, repair the alternator and sell it on ebay. You could keep it as a back up since it will wire in the same as the Plane Pwr unit. The repair could be just a $30 voltage regulator? I helped one guy and that is what we did. He ordered the part and installed it and it worked fine after that. Regarding Van's current 60 amp unit, they have changed vendor's. The new (aftermarket) 60 amp units they sell have better quality and consistency I'm lead to believe. The down side is they went up in price. I believe they're pushing $200.

So Plane power or repair?

You may find after repairing your old alternator with a VR, diodes, brushes it works for a very long time? If there is any major problem, like stator or rotor, get a new unit (keep the old one for core value). That's what the rebuild shops are doing. It's cheaper to buy a new (aftermarket) alterantor than rebuild old parts.

Get the Plane Power in IMHO, its a good value and you are getting more than a plan ol rebuild or aftermarket Chinese alterantor.

PS: All you 60 amp Van alternator operators, DON'T CYCLE THE ALT SWITCH WHEN THE ENGINE IS RUNNING. TURN IT ON WITH THE MASTER BEFORE START AND LEAVE IT ON UNTIL SHUT DOWN WITH THE MASTER. Premature VR failure can occure from playing switch monkey. They are all designed to go on automatically with RPM, not by manual control while under load.

tadsargent · #7 10-16-2006, 04:27 PM

Been there, done ......

Before you chuck it and buy another, take it to a good alternator shop for testing. Two possibilities. One the Reg. is bad and for $50.00 you get anothter one, it does not have to be and exact replacement. A good shop can fit any Regulator on it. Second, the brushes were not shimmed correctly when it was reassembled. Again a good shop will catch this as well. I have had 2 Van's alts. checked by my shop and in both cases he caught the brushes misaligned. A friend of mine has an RV8 and his wire came lose at the field connection so check that also. You only need one wire to the field and then the B lead to make it work.
Tad Sargent
"Stripes"
7A 160 hours since Feb. '06 and 60hours since alt. woes

MSFT-1 · #8 10-16-2006, 05:32 PM

I have an RV-8 that had the stock Van's supplied 35 amp alternator with external VR and no OV protection. On a cross country trip back home a couple months ago, I smelled a burning smell and then lost the charging indication. I landed and drove the rest of the way home (120 miles). The next day I drove up to the airport and investigated the problem.

The smell was from the connector on the back of the alternator which had melted into a gooey, stringy mess. After I removed the alternator it was obvious that the front bearing was completely destroyed. Holding the alternator by the pully, I could wobble the whole alternator by just moving my hand a little bit.

I decided on the 60amp Plane Power alternator. I bought it (from Van's) and put it on. Very impressed with the build quality and the completeness of the package. It fit perfectly and worked perfectly. 14.1v steady (not the 14 to 15 volts I used to get from the old one). I definitely would buy it again. BTW, it uses the same belt as the old alternator which means you don't have to remove the prop to replace the belt.

I talked on the phone to a tech at Van's about the old alternator and he said, "Yeah, the company that sold us those misrepresented them. They have proven not to be nearly as durable as we had hoped. I wish we didn't sell them."

As far as B&C is concerned, their product looks very similar to the Plane Power product but is $200 more expensive. I just couldn't see where the $200 premium comes from. I have heard that people are very happy with the B&C product.

Bruce
N297NW

jcoloccia · #9 10-16-2006, 05:38 PM

Just one note about the crowbar overvoltage protection. It's not a Rube Goldberg approach but common and accepted practice. The point of the crowbar isn't to trip the circuit breaker. The crowbar immediately shorts to ground, quickly and completely removing the field. The circuit breaker then trips to keep you from burning up the wires.

The tripped circuit breaker is incidental. You could just as easily use some sort of current limiting device, I suppose, if you really wanted to (this would probably introduce other headaches). The main action of the crowbar is to remove the field.

Ironflight · #10 10-16-2006, 05:43 PM

Seriously, I'm sorta surprised I have had no problems so far!

I've got the Van's 60 amp that came in the FWF kit back in the spring of 2005, and it's now got 291.5 hours on it. I have no idea how long it will last, but it looked and felt mechanically good when I checked it during the condition inspection (I took the belt off and spun it by hand to check for obviously worn bearings) a couple weeks ago.

I am realistic about it - it is not an expensive unit, and of potentially unknown quality. That is why I also have an SD-8 backup alternator which will support my usual in-flight load of about 6 to 7 amps for as long as it takes me to get to safety. I did do my best to maximize its life by being very careful with alignment, and using a very solid mounting bracket and bracing link to the starter pad.

My old Grumman ate three alternators in about 1500 hours - all of them certified, "highest quality" (yeah, right!) aircraft parts that cost around $500. To me, running the ND is simply an experiment to see how long it will last.

Paul