load analysis help

I'm doing my load analysis and I have a few loads I can't find as of yet. I would like to get this done so I can purchase my materials and start wiring the front end of the bird.

I need the amp loading of the following items (14 VDC of course):

E-MAG
P-MAG
Van's flap motor
GRT EIS-4000
TruTrak ADI
Ray Alan trim servos under load

I'm rolling my own electrical system and am curious as to what most folks do. Did/will you "roll your own" or "smoke" Van's prepackaged brand? If you rolled your own, did you use one of the Nuckols Z diagrams?

Jekyll

my numbers

All numbers are amps.

E-MAG = 0.70 @ 2,700 rpm
P-MAG = 0.00 above 2000 rpm; 0.30 at idle
Van's flap motor = 3.0 with load (I have seen 1.5 for unloaded)
GRT EIS-4000= 1.1 amps total ( 0.65 display, 0.20 Fuel P, 0.20 Oil P, **)
TruTrak ADI = 1 amp max servo, head = 0.30 amps, total 1.30
Ray Alan trim servos under load = 0.15


** EIS if you have fuel transducers, fuel flow or other transducers that use the EIS for power, add for each added aux transducer. I don't think the FF transducer uses much.

Most of these numbers are on the manufactures web site. These are fairly small users of pwr. The lights (NAV, Strobes, Landing) and the Com Radio during Transmit are the biggest users.

All number are unverified use at your own risk. Should be in the ball, park the flap load is the only one not nailed down, but 3 amps is a good number to cover you, no doubt current is based on load on flap, ie on ground 1.5, in air 3.0. Good luck. G

More flap motor info

FYI, but maybe not much help.
I found the motor performance charts a few days ago for the flap motor provided by Vans. Unfortunately, it simply shows a variation in current depending on the torque asked of the motor. No particular figure for our application. It varies between .5 and 8 Amps and a peak locked rotor current of over 12 amps. Our application is somewhere in there. I had already decided to use the 3 amp figure (because of other flyers reporting the same) posted by George above.

If I run into an installed electrical load problem, maybe I'll delete the cappucino maker..

Got charts

rzbill said:

FYI, Our application is somewhere in there. I had already decided to use the 3 amp figure (because of other flyers reporting the same) posted by George above.

If I run into an installed electrical load problem, maybe I'll delete the cappucino maker..

Click to expand...

I believe it has been measured, but good info. Not sure who has measured it, but my flap motor is in a box, are in a box right now. Have a link to the chart you speak of? PS what cappucuno maker did you get. Thanks G

Here you go

http://www.pennmotion.com/pdf/lcm_bulletin.pdf

Memory says the 9X34 motor chart is the right one (I don't have the flap motor handy to read the part number right now.)

No coffee maker purchased yet, George. Two choices in my view.

Similar to a polished RV, a Pavoni Europicola would fit the bill.

However, to reduce pilot workload, I am investigating a Capresso C1000 because it is 100% automatic, including cleaning....

Flap load

I'm running one 5 amp breaker for my flaps and elevator trim. 85 hours and no problems.

Roger Ping
RV-9

Jekyll said:

I'm doing my load analysis and I have a few loads I can't find as of yet. I would like to get this done so I can purchase my materials and start wiring the front end of the bird.

I need the amp loading of the following items (14 VDC of course):

E-MAG
P-MAG
Van's flap motor
GRT EIS-4000
TruTrak ADI
Ray Alan trim servos under load

I'm rolling my own electrical system and am curious as to what most folks do. Did/will you "roll your own" or "smoke" Van's prepackaged brand? If you rolled your own, did you use one of the Nuckols Z diagrams?

Jekyll

Click to expand...

Although I agree with George's numbers, you can end up with a far too large system unless you think a little.

You should size the P-mag wiring & fuse/breaker to support the whole load (gene failed), for the alternator load you can ignore it.

Flap motor & trim motor load can be discounted from alterntor sizing due to intermittent load.

Ensure that any single failure (including master relay) will not take out flight critical functions - such as TT ADI.

Yours, Pete

Jekyll said:

I'm rolling my own electrical system and am curious as to what most folks do. Did/will you "roll your own" or "smoke" Van's prepackaged brand? If you rolled your own, did you use one of the Nuckols Z diagrams?

Jekyll

Click to expand...

I found this Yahoo users group that might have some useful info for you.
21c_el_sys ? 21st Century Electrical Systems
-mike

Alternator sizing

penguin said:

Although I agree with George's numbers, you can end up with a far too large system unless you think a little.Flap motor & trim motor load can be discounted from alternator sizing due to intermittent load.

Ensure that any single failure (including master relay) will not take out flight critical functions - such as TT ADI. Yours, Pete

Click to expand...

Good points, and I would add have some head room on your alternator. All your steady state electrical items should not be more than say 50% to 75% max of alternators total capacity. The more "head room" the better. The cooler the alternator runs the better.

There are things you may not consider, like battery charging. Granted the worst time is right after start, the battery can indeed draw a large amount of current when charging after being drained. Granted to sustain a fully charged battery is low amps, it is not free.

Also many forget all the little items like .75 amps for the master relay for example, so don't over load the alternator. On the other hand don't go crazy with a massive heavy alternator. A day/night VFR should get by with 40-45 amps. A 60 amp should do a full IFR plane, however people are putting in those Coffee makers and microwaves. The biggest savings can come from **LED nav and strobe light (when it comes and it will) technology. Right now all my lights are taking almost 20 AMP!. The rest of the plane is only 10-12 amps max.

George

**PS, caution on the LED NAV lights. Many cottage industries are making NAV lights and some I believe are not even close to meeting the FAR requirement, which we MUST meet. The big name brands, like Whelen only make expensive 28 v units. Clearly LED's can meet the requirement, but the color, intensity and coverage is very spacific and complicated and by inspection and some casual familiarity with the Regs, many of the LED NAV lights on the market don't look acceptable. Some are too bright in the wrong direction, or not bright enough in the right direction if you follow me. Buyer beware.

gmcjetpilot said:

**PS, caution on the LED NAV lights. Many cottage industries are making NAV lights and some I believe are not even close to meeting the FAR requirement, which we MUST meet. The big name brands, like Whelen only make expensive 28 v units. Clearly LED's can meet the requirement, but the color, intensity and coverage is very spacific and complicated and by inspection and some casual familiarity with the Regs, many of the LED NAV lights on the market don't look acceptable. Some are too bright in the wrong direction, or not bright enough in the right direction if you follow me. Buyer beware.

Click to expand...

Excellent cautionary point George. But, if one is thinking about rolling his own or purchasing one of the several available out there, we should be easily able to meet the regs by just following the Plans (FAR 23.1385 through 23.1401).
We are, after all, building the whole aircraft by following the plans.
-mike

penguin said:

Flap motor & trim motor load can be discounted from alterntor sizing due to intermittent load.
Yours, Pete

Click to expand...

Pete, how right you are. I'm doing just that but, since I'm rolling my own, I need the load to wire it up properly.

Jekyll