Thorp Air Command - T18.net

Hello fellow thorpers, Just about everything on my thorp is electronic, so when I have everything on, the alternator can't keep up, so I am looking to upgrade my 70 amp alternator to a 100 amp or better. anyone using a high output alternator in there birds? If so what model are you using? Thanks in Advance. Ira

100 AMPS!! Really? That's a ton of power, Ira. I know of houses that don't have that much. You sure you need that?
Cubes

I have a 35 amp alternator that drives , three electric fuel pumps, two radios( one with GPS),strobes, marker lights, two axis auto pilot, electric instruments,and a aux plug for a computer. The battery is a 32 Amp wheel chair battery.
Sounds a if your current alternator is not doing it's job. You can weld with 70 amps.

Have you done a proper load analysis?

The one thing I can think of that uses a lot of juice is pitot heat. Do you really need it?

_________________
Bob Highley
N711SH
SN 835
KLAL

Just a simple question: does all that responded use the airframe for ground for their electrical systems??? Dan

I use the aircraft for ground on most things. I treated the main ground areas for corrosion and keep them greased. Alodine and anodizing are not good conductors, however. I have seen several planes where the engine to airframe ground is inadequate or missing altogether. All these things can and will add up to poor electrical performance. With all of my stuff running including the strobes, I never see more than ten amps after the initial recharge from the starter use.

_________________
Bob Highley
N711SH
SN 835
KLAL

Ira : Are you running ECM gear in the baggage compartment ? What kind of alternator do you have on it now ? First thing I would do is have the alternator tested to see if it is generating full power . Aye Captain !

RB

With everything on: Dynon, Transponder, Navcom, Gps, Tcas, Strobe lights, Autopilot, Position lights, Panel lights, landing light, Egt, intercom, and all Engine monitoring instruments, oh, (don't forget the hot plate for warming up my burritos) I am showing 12.5 volts, the Odyssey 680 requires 14.0 to 14.7 volt charge rate to maintain positive charge. what really takes me over the edge is the landing light, I know we don't continuously use our landing lights other than for landing, I would feel more comfortable knowing that I am not discharging my battery while using it, the landing light pulls 9 amps. I have yet to do a load analyses to see my total amp draw is. Rich, the alternator is off of a 80's Suzuki samuri (I know, buy American, my bad) it's lite and compact. Dan and I checked alternator everything on except lighting it's putting out 14.2 volts. Thanks, Ira

100 amp alternator/generator . I think we had one on the T-28 with the R-1800 radial ? Had to power all those 20 pound radios , TACAN and ADF . More power Mr. Scott ! >:(

RB

9 amps on the landing lite ? Is it one of the PAR 36 bulbs ? I have an LED lite that has 9 LEDS in it and only draws 1.3 AMPS . Same output or better than a 55 watt halogen bulb . I too have an all electric panel and after engine start I rarely see more than +10 AMP on the meter and then it goes to just above zero for the rest of the flight .

RB

Ira, I didn't mean to stir up a hornets nest. But I think you should be able to get by with a lot less than 100 amps. Yes I have my ground circuit through the airframe. However, I run an additional cable to the motor mount and one from there to the engine. Try to do a load analysis and see what each system is drawing. Remember, the breakers are there to protect the wiring. So the current draw defines a combination of wire size and length. I'm sure that's not new to you, just restating fact. If you do not have an amp meter installed, I suggest you put one in, along with over volt protection.
Cubes

No hornets nest here Mr Grahn, you have some valid points, I believe I my have some other gremlin lurking about, possibly a ground issue of some sort. I am going to do some investigating on this issue. I do have a amp gauge installed (UMA) I will do a cross check with another gauge to confirm. Thanks to all for your input.
Ira