The Eternal Alternator Choice Topic

[Frank Green]

I followed Homer's lead and got a field approval for the Denso. Been running it for a couple of years now and it has been flawless. We used a 40 amp denso and controlled it down to 30 output by putting a 3 amp breaker on the field wire. I believe Homers and mine paperwork is on Andy's website. The only issue I had was the output stud on the alternator was pretty close to the exhaust pipe but I corrected that by taking the back end off and rotating it 180 to put it on top. I found some pics from when I did the install and the master box mod. I added a before pic also.

[Clayton Harper]

Frank,
I know the Feds don't allow the use of the 337's approved data any more, but if I could get a copy of what you sent in for the field approval it would give me a starting point. If I didn't already have the Denso, I might just buy a Plane Power set up. If anyone has a suggestion please chime in.

[Pacer 24C]

I have a PlanePower on one plane and an orginal 20 amp generator on the other - 20 amps is plenty and the generator is simpler and only weighs 8 oz more than the PlanePower -(so called light alternator)

[wyandot jim]

Yep, I still have a Gen. on the Bonanza and Starduster 0-470. The way I see it if I want to make the plane lighter I'm the one that needs to lose the weight-50# Gens work great now with all the low amp draw.

[ysifly2]

Frank,
I know the Feds don't allow the use of the 337's approved data any more, ....

I just completed two field approvals, one for installing the EI Fuel Gauge and one for B&C Alternator.
The EI Fuel Gauge was solely based on a previous 337 field approval.
The B&C Alternator was based upon the STC and FAA-PMA approved alternate for the PA18/19, a 337 field approval for the same on a Certified Pitts and 337 field approvals for previous, non-PMA versions of the B&C installs on PA22's. They did ask why I didn't choose to install the STC option available (i.e. plane power) and wanted me to refer to that STC.

My position was as follows:

"Please find attached the 337 for the subject mod to reference previously approved 337 field approvals for the B&C Alternator. Two of these approvals were for same type PA22 installs, but reference the part number for the B&C alternator as L40. This is the part number reference for the non-PMA alternator, prior to the availability of the FAA-PMA option of the BC400-2, as being utilized for this installation. Also referenced is a more recent installation of the B&C BC400-2 on a certified airplane other than the PA18/19 of the STC, in this case a Pitss S-2A via a 337 field approval.

I have revised the subject 337 to reference the previously approved 337s of the same manufacture and alternator as felt that more appropriate. I am aware of the other STC option you noted via STC SA10682SC, this is supplied by a Plane Power. I don't see that it would be appropriate to reference that STC on the field approval, as the installation procedures and information for that installation are not being referneced for this installation.

The B&C Alternator option were chosen for a few reasons, including the fact that it is a FAA-PMA approved component. While the model elgibility doesn't currently include the PA22-150 series, the PA18/19-150 are of same manufacturer (Piper), similar in firewall forward installation and electrical systems,and identical engine, in this case Lycoming O320. The BC400-2 alternator was also chosen to match up with a light weight starter being installed from B&C (STC with model elegibility including PA22) and using the PA18/19 STC installation instructions for the guidance on the 337 install.

The B&C Alternator is a 40amp altenator weighing in a 6.1lbs, while the Plane Power is a 70amp alternator weighing 10lbs. For this installation on N4763A, day/night VFR airplane, the 40amps, at 80% max continuous per AC43.13, Ch 11, Sec 3, Par 11-33 & 11-36, provides 32amps supply for a total MAX load (all electical loads operating and transimitting) of 16.4amps, or ~50% of alternator capacity. Max continuous load is 12.5amps, resulting in ~40% of alternator derated capacity. Based upon this, the determination was to save the 4lbs versus additional over capacity of the alternator."


In the end, they still wanted me to reference the PP STC... I complied and added a statement, after referring to install being based upon the PA18 STC and previous irks approvals and that it was "similar to STC PP"



Bryan

[Rick-CAS]

That was probably my 337 for the B&C PA-18 STC on the Pitts S-2A. Easiest field approval I have ever done. Also did the same on a PA-22.

[Bruinpilot]

A friend has an interav alternator kit that he doesn't need and offered it to me for free. Is this thing worth the work to upgrade my old generator? Does anyone know how much weight it will save? I don't have interest in a lot of avionics, but a landing light might be nice someday...

[Steve Pierce]

They are good units. You have to add a circuit breaker. The nice thing is that you have power when taxiing and at low power settings.

[bigjohnnie]

My 2 cents worth.... I agree with Steve. You have charging power at low power settings. Alternator conversion (B&C) was my first upgrade to my '55 tripe. I could then fly at night , and enjoy it with no worries.

[Gilbert Pierce]

My InterAv has been trouble free for 14 years and 1200 hours.