Overvoltage Protection Help

[avrojockey]

Van's supplied Nippon-Denso alternators are internally regulated and in their stock state you're not controlling the field with the alternator switch or CB, you're only removing a signal to the regulator to do it's job (IGN). These regulators get field power internally and if the regulator fails there is a remote possibility it could fail in overvoltage and the interruption of the IGN signal with a crowbar over voltage module won't do anything to stop alternator output.

It's suggested to add a contractor to open alternator output (B lead) to the system. This is one way of doing it. There is the possibility that sudden interruption of alternator output this way will fry your regulator, but if the regulator wasn't doing its job then it's not an issue.

Option #2 is to modify the internal regulator to remove internal field supply and make the IGN wire a true field wire. Then use the OVM to interrupt the field. This is the route I took and how a popular PMAed aircraft alternator company modifies ND alternator and sells them for a premium. Here are the directions from Bob Nickols to accomplishs this...

http://www.aeroelectric.com/articles...rnator_Mod.pdf

Also here's a good write-up by another Tim that clearly shows this same mod made to ND alternators by name brand companies. https://www.myrv10.com/N104CD/mainte...cts/index.html

[Flyyak]

Wow. Great articles. Do you know if the Van’s supplied alternators are true Nippondenso alternators?

[Steve Iacoviello]

I believe that Van’s supplies Plane Power alternators in their FF kits. Plane Power alternators have OV protection. My FF kit from 11 years ago had a Plane Power alternator.

[Bill.Peyton]

Why would you risk all your avionics and a possible fire? Use an aircraft alternator such as the BandC, with an external regulator and OV protection circuit. If you are not familiar with working on electronics, modifying an alternator probably not for you. I agree with Danny. Also, I would not use the Shorei batt. Earth X has spent a lot of effort getting their Lifpo batt certified and safe for aircraft use. If you insist on using a Lifpo in your aircraft, you might consider them. I personally have been using the Odessey’s and get about 5 years out of them.

[avrojockey]

Originally Posted by Bill.Peyton

Why would you risk all your avionics and a possible fire? Use an aircraft alternator such as the BandC, with an external regulator and OV protection circuit. If you are not familiar with working on electronics, modifying an alternator probably not for you. I agree with Danny. Also, I would not use the Shorei batt. Earth X has spent a lot of effort getting their Lifpo batt certified and safe for aircraft use. If you insist on using a Lifpo in your aircraft, you might consider them. I personally have been using the Odessey’s and get about 5 years out of them.

Though I agree the modification of a voltage regulator should be left for the familiar, it is hardly difficult and not risky. If you're building an airplane it is certainly within the scope of those capabilities. Besides, BnC and PP are just ND clones modified for OV protection and/or external regulation. They were certainly smart to just modify what works very well (ND alts) instead of reinventing the wheel.

I see your point though...if you're dishing out fat stacks for an airplane why not just pay for the already modified ND alternator from BnC? I just chose to modify the Van's ND alternator so if I'm in BFE I can purchase the same rig from Napa to get airborne rather than pay for a rental car and chance my life on the road with the normal crazies...now that is risky!

[Flyyak]

I have done a great deal of research and my alternator is Van’s 60A 14684 alternator which is an alternator that has been used for many years in the automotive industry. There have been several articles written as they relate to modifying these alternators to an externally regulated alternator with overvoltage protection. Nuckolls is the author of one modification and a couple of other (I think engineers) have simplified the modification.

I will use the process set forth in the last article in kitplane using the spacer and removal of the internal regulator with the addition of the TranspoV1200 external regulator with overvoltage protection (Amazon for $69.00)

I would appreciate others review of this modification of the 14684 alternator that many RV’s are probably using. I think many of us non engineers or electrically handicapped folks will appreciate your opinions and insights. Thanks

http://www.aeroelectric.com/articles...Conversion.pdf

https://www.kitplanes.com/rewiring-a...so-alternator/

https://www.kitplanes.com/alternator...major-surgery/

[rjcthree]

I’m running a plane power 60a and planning my eventual failure/ defection (currently 133 hours, picking up my pace). I’m thinking a real ND internally regulated alt with a Perihion OV is an elegant and not-intrusive solution. How/ where do you get a REAL NEW ND alternator?

[Flyyak]

From my limited research, I do not think the internal regulator plus perihelion OV module will solve the run away alternator. When one reads Mr. Nuckolls he points out that interruption of the alternator field wire will not cut off the run away alternator. But he also points out that if the Nippondenso alternator is modified to accept an external regulator, then an overvoltage devise can be added whether it is separate or part of the external regulator. I have now read about a few, BandC and TranspoV1200. You may be able to use another regulator and the perihelion as the OV module.

[rjcthree]

Maybe my understanding is off, but I thought if the field, which is externally controlled, is turned off, the alternator is shut down completely. In other words, the alternator makes no power without the field energized. The OV module does this- opens the field circuit when thinks her whonky.

[Wunderon]

fwiw, confirming that the Van’s-supplied Plane Power AL 12-EI60B does include internal crowbar overvoltage protection, https://planepower.aero/wp-content/u...Instructions-1