L

longline

Well Known Member
I am trying to locate someone that has this gear driven alternator installed on a Lycoming. I want to find out the real world output of this gem when at a cruise (engine RPM) of 2500 RPM, 2100 RPM and at what RPM it stops producing power. B&C has a chart for this unit, but I am curious what others have experienced.
 
It easily carries my full load of 30 amps in cruise at 2370 rpm's on the RV-10. next time I am up I will see when it stops producing power.
I check it about every other flight, and have run it for over 40 minutes at a time.

Vic
 
Vic

that effort would be much appreciated. I have two complete electrical systems installed, and have been trying to figure out just how much help the gear driven alternator will provide.
 
I just installed one on my RV-10 and you can rely on the 30 amp advertised output. You may not get this at idle, but that is not the function of the alternator.

I added blocking diodes on the output of this alternator so I could feed both left and right vital buses (think "Avionics #1 and Avionics #2) so that there would be no cross feed between the two buses, and would be on the load side of both master solenoids so a hard fault could be isolated by opening both master solenoids.

A lot of ways to do this.

Carl
 
OK. Finally rmembered you asked me to do this, so yesterday I was doing some high altitude testing and I switched on the the standby alternator while descending from 19K'. It carried the entire load of 25 amps at 13.2-13.4 volts (that's what the standby regulator is set at) all the way to touchdown. It only started to drop off a little at low idle RPM's. I was very impressed.

Vic
 
Hey Vic---in reference to Andy Turner's post on efficiency, the next time you are up that high, can you tell us the fuel burn, and stuff.
Tom
 
Thanks to Vic and Carl

for the information. I am looking at maxing out the loads, under "normal" operations, at about 11 amps on this alternator. If called upon to power all flight critical loads I am only looking at 14 amps after non critical load shed. (It would be much lower if I decided to do away with some avionics.) I am now comfortable with the plan.
 
longline said:
for the information. I am looking at maxing out the loads, under "normal" operations, at about 11 amps on this alternator. If called upon to power all flight critical loads I am only looking at 14 amps after non critical load shed. (It would be much lower if I decided to do away with some avionics.) I am now comfortable with the plan.
Click to expand...

If you are running a typical EFIS panel along with a power hog like the GTN-650, your 11 amp target load may not be achievable. The good news is the alternator will put out much more.

Carl
 
Tom, I thought I took a picture, but can't find it. :(
Here's what I remember:

15.9" MAP
2370 RPM (MT 3 blade)
10-11 gph
159 KTAS at cruise
OAT 30F

I climbed straight to 17,500 from a 95 degree day on the ground in Atlanta. Oil temp maxed at 192, and came down to 178 once I leveled off. CHT's hit 382 initially then stabilized around 350-360 for the climb. I climbed at 110+ KIAS until 10K', which gave about 1K' FPM ROC average, then I set it for 700 FPM until 12,500 and then 500 FPM until level off. A/S was about 96 KIAS at level off in the climb. CHT's were around 310-320 in cruise, and then around 278 for the descent, carrying some power on the way down to keep it warm.

The Lightspeed ignition was showing about 34 degrees of Advanced timing up high. Turning off the mag did nothing. Turning of the Lightspeed was very noticeable.

I think the electroninc ignition and the 3 blade prop really shine at high altitudes on the 10.


I was at 17,500. Density altitude was 19,300.

Vic
 
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