overvoltage protection

[RudiGreyling]

HI George,

Thank you for the time to write up the detail...I learned a lot.

Regards
Rudi

[jonbakerok]

Originally Posted by gmcjetpilot

1-Wire the NipponDenso alternator as in the application it's designed for. I HIGHLY recommend you wire in the warning light, and the remote voltage sense. George

Not knowing any better, I just wired mine they way they told me. A warning light would be a heck of a good idea! Which wire is it? And what is the "remote voltage sense" wire for? I thought that's what the one that had me hook up to the alternator switch was for.

How about posting a wiring diagram?

[Davepar]

Nice write up George.

I know I've seen a sketch of the ND plug and what each wire does, but I can't remember where I saw it.

Here's a write-up of some experiments that Mickey did on his ND alternator.
http://www.rv8.ch/article.php?story=2004112513263691

[Davepar]

This isn't the original diagram I saw, but looks like a very good article:
http://www.f1-rocketboy.com/alternator.htm

See the diagram and photo near the end.

[Davepar]

Here's a section from Toyota's training manual, which appears to use a very similar alternator. There are diagrams that show how the alternator operates before the engine is turning, during normal operation, when the S lead becomes disconnected, and when the B lead becomes disconnected. There's even a self-test at the end.

http://www.autoshop101.com/forms/h8.pdf

Now I'm going to go do some actual work.

[PapillonAir]

Geez, sorry folks, did not think that my comments would cause such a reply!
That WAS my experience, and that is what I had heard from others, so since I do not appreciate being called a liar, I will refrain from any future comments in this section.
I thought that RV'ers were suppose to be nice folks?

[gmcjetpilot]

Here are great links about the ND in particular and alternators in general:


Overview of ND alternator and wiring
http://www.autoshop101.com/forms/alt_bwoh.pdf

More specific ND info (wiring) troubleshooting as installed in a Toyota
http://www.autoshop101.com/forms/h8.pdf
(not all ND alternators have remote V sense)

Niagara has a good dwg showing the warning light (ND w/ out remote volt sense)
http://www.niagaraairparts.com/alt-instr.pdf

Good General overview of alternators
http://members.1stconnect.com/anozir...alternator.htm

Remote Voltage sense and Why
http://www.madelectrical.com/electri...esensing.shtml


The Nitty Gritty, Basics of alternator & regulator theory / physics: electromagnet, magnetic FIELD, 3-phase AC, stator, rotor, rectifier and voltage regulators:
Fundemental Physics of alternators, with animation


Inside of Typical internal Voltage regulator
http://www.freescale.com/files/analo.../MC33099FS.pdf
_OR_ more detailed spec sheet (see page 2)
http://1url.org/go/1gx7qm

I mentioned that I don't like the crow bar (with I-VR alternators) due to possible faults trips that can damage the alternator. Since the alternator has OV protection and the chance of it happening is slim to nil, why put it on. However if you MUST add it on for comfort, I agree with a previous post, the periheliondesign's OV protection device should be more stable:
http://www.periheliondesign.com/LOVM.htm

Enjoy, This should answer a lot of questions. The fun part of building is learning. I know I have. Cheers George

[gmcjetpilot]

Originally Posted by PapillonAir

Geez, sorry folks, did not think that my comments would cause such a reply! That WAS my experience, and that is what I had heard from others, so since I do not appreciate being called a liar, I will refrain from any future comments in this section. I thought that RV'ers were suppose to be nice folks?

Dear Dale:

My sincere apology if you thought you where being called a liar. I am nice and at no time did I call YOU liar. I did state that the I-VR thing is ripe with stories presented as facts (lies) as in.....A false statement presented as being true; a falsehood.

This was not the case here. You clearly presented a story you heard and stated so. However some repeat stories as fact and can not provide any detail. Again, I just like to know what really happened and why.

The story you related you stated was second hand. It may have been 20th hand, I don't care. What I do care about is getting useful INFORMATION to improve safety for everyone using internal VR alternators. WHY MAKE THE SAME MISTAKE IF IT CAN BE PRESENTED. If this happened than why? It would be great to hear from the person it allegedly happened to.

This story and many others do have holes; this is in no way an indictment of you Dale. It does represent my frustration with something that is so important, as flight safety, being polluted with rhetoric, which is not your fault. You clearly made your statement, which in turn brought up a good discussion. I DO NOT have all the answers but would like answers. I try to back my opinion up with facts. I could be wrong, and if corrected I would be happy to learn. That is important. Bottom line WHAT IS THE BEST WAY TO USE AN I-VR ALTERNATOR IN YOUR AIRPLANE?

I did appreciate your post Dale and your experience with B&C. It was quite clear you made the statement in good faith to help.

Again, sorry if you took it wrong and apologize if I offended you.

Sincerely George

[PapillonAir]

George et. al.
When I said "second hand" I meant that I had heard it directly from the guy that had the problem, so now that I am passing it along it is now second hand info.
The guy is not an "on-line" type of person, I do not think he even owns a computer. He is an experienced RV builder and this problem was with his second RV project - first was an RV4 which he has been flying for about 10+ years, the recent, and problem aircraft was his version of a "super six" which started life as an RV6 but now is much more. I belive he had roughly 30+ hours on the plane with no problems, had done his FAA fly-off and even had taken it to OSH this past year. The problem he related was on a recent flight, cruising along with everything normal, he decided to secure the alt. switch to see what sort of batt. capacity he would have available should he lose the alt. output (which I think is one of the reasons to have control of the alt. output, in addition to trouble shooting or securing a mis-behaving unit). He stated (in front of our chapter meeting) that as he re-activated the alt. he almost immediately got smoke in the cockpit, along with the little trim indicator meter literally blowing up and shooting out sparks and smoke!, all his "Vans" panel instruments were totally dead. He re-secured the alt. and got the thing on the ground asap. He then went on to indicate that the alt. he purchased from Van's was indicated to have internal voltage regulation and OVP. So, he was not really sure just what had happened, he found all his Vans engine instruments were melted / smoked with bad smells, and all other instruments / avionics having trouble or inop. So, at the point he reported, he indicated that he had smoked about 9k worth of stuff, but was getting some good news from the avionics companies that were able to repair a lot of the damage, so he closed with the statement that he now will be going with the externally regulated type alt. and hopefully not having to go through this again. At this point in the meeting, a close friend of his stood up to expand on his understanding of the problem, I think this guy is an electrical engineer - or at least gives that impression. He drew all sorts of diagrams on the board and related that there are two basic types of control circuitry used on all internally regulated alt. on the market today, he went in to more detail on which type the problem aircraft probably had, and why the problem most likely occured. He indicated that from the damage he saw, that the alt. output had easily exceeded 2-300volts, which is why so much damage had been done, in that the fuses in the aircraft will only protect from over-current situations and not over-voltage. He indicated that in most situations that the internal systems work just fine, but the one type, can at times, if certain internal problems exist, go in to a run-away situation should the control lead be de-energized / re-energized - which is what the owner inadvertently introduced in this situation.
Now, in my own experience, when I purchased my alt. kit from Van about 4 years ago, all that they had was the non-internally regulated types and you were on your own to get something for regulation. I was aware of the BC unit, so I purchased that one as opposed to "experimenting" in trying to use some sort of automotive unit, which may have all sorts of specialty neuances.
The system worked great for me, except for at about 5 hours on the plane, my alt. bearings began to sing / and being ultra cautious at this point of any strange noised eminating from under my cowling... I chose to remove the alt. for inspection. I took in to a local auto alt. shop for testing and sure enough they found that my "brand new - rebuilt" alt. from Vans had bad bearings in addition to them finding the brushes almost worn out too... $55 later, had both replaced... my call to Vans was met with "will send you another but you will have to pay full price" Now, I do understand that the thing was a re-built from the start, but still disappointing none the less. So, in the time since then, I guess they have switched over to the internally regulated type... so, with my experience with the alt. it did not really suprize me that something had gone wrong, and made me really glad that I had the external ov protection!
My intentions were to just point out that problems can develop, and my eperiences with the BC ovp have been fine... of course I had no option when I purchased my alt.
I guess the bottom line is here... if you have an internally regulated alt. you had better not be shutting the thing off in flight with the old circuit design of having a separate alt. switch ie. the Cessna split master switches.
Dale,
Should you have further questions, and as to not bore the viewers to death you can contact me directly at drwittman_at_comcast.net

[rv6ejguy]

I have been using IR Denso alternators for over 20 years in street, race cars and aircraft. In both race cars and aircraft, we shut off the field wire via the kill switch or field switch. Never had an ND alternator fail yet from doing this.