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How many DERs does it take to change a light bulb?

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A lot!

I'm gonna put an electric A/C system in my Commander (28v, 85 amp alternator from the factory). Draw is 65 amps. Gonna have to make up some power. There used to be a 150 amp alternator STC replacement from Plane Power, but Hartzell bought them out and one of the two managed to piss off the manufacturer of the stator for those alternators during the sale of the business, and they washed their hands of them, so now Hartzell has to find a new supplier, they tell me January next year at best. Meantime there's a 100 amp option but that's about it.

The obvious way to save a lot is to go through the airplane like a dose of salts with LED light bulb replacements.

Landing/taxi lights are a 20 amp draw with incandescent bulbs. LEDs get those down to ~3-4 amps.

Strobes are about 10-15 amps, LEDs get those down to ~6 amps.

Nav and position lights are another 10-15 amps, LEDs get those down to ~2 amps.

I figure I can make up 30 to 35 amps just in light bulbs, albeit at the cost of buying them (they're not cheap, 1000 dollars just for the landing/taxi replacements).

Looks like 4 bulbs are PMA'd, 3 are STC'd but not for my airplane, and 3 are TSO'd but no PMAs or STCs yet. Since there's so few of us flying around Whelen forgot to include my airplane in their bulk STC list for the LED lights they're working on, even though they're the original supplier for a lot of these bulbs. On the upside we have an electrical DER assisting us with the A/C install anyway so it'll be an "oh by the way, while you're at it, lets talk about light bulbs!"

I have more electronic instruments than most (only mechanical gauges in my panel are the standbys), and even at that it's mostly just the bright brights, as my toddler niece says.

I'm gonna get the shunt on my JPI 930 moved from the charge side to the draw side so that I can get a good reading on my worst-case-scenario amp draw, but it looks to be in the neighborhood of 50-60 amps and over half of that is light bulbs. :eek:

So if you ever wondered where all that power in your airplane goes when your panel is mostly steam gauges? Light bulbs, that's all of it!
 
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