lostpilot28

lostpilot28

Well Known Member
I'm sitting out at my hangar and was attempting to set the timing on my P-Mags. I have my S700 2-10 switches wired according to the Aerolectric connection, with the P-lead going to pin 2 and ground in Pin 3 (on the switch). I then have 12V system power going to pin 4 and out to the P-Mag on Pin 5. The problem is, in this configuration the P-lead stays grounded when the switch is moved to the middle position. Also, 12V power is not "on" at the P-Mag in this position.

So, I've been trying to figure out how to configure the back of my switch. I have no "ground maintenance" mode...I just want to set it up so that "Down" is P-lead grounded, middle position is P-lead ungrounded with the P-Mag running on it's own power, and Up is when the P-Mag is running on System Power.

I don't think the Aerolectric connection is right in the Z-13/8 diagram. Anyone have any suggestions?
 
Sonny,

See page Z-9 Appendix Z Aeroelectric Connection terminal locations. Note the difference between fast on and screw connections.

Maybe this will help

Ken
 
Thanks Ken,
I've been through a few iterations with connecting these things that I'm not sure if I've tried that, but I think that's the original way I had them hooked up. I'll certainly try it again tomorrow when I'm back out at the hangar.
 
Me too

Sonny, when you get this sorted out will you post the result? I have a pair of Pmags still in the box and will be putting them on in a couple of weeks. Also have the same switches, and was planning to follow the same Aeroelectric diagram.
 
Be aware that the switch wiring diagrams in the AeroElectric Connection doument are not always correct for Carling switches - at some point in time, right side pins were swapped with left side by the factory (nice, eh?). This was the case for me, and it messed up my wiring til I figured out what was going on. Bob has acknowledged this in his forum, but Im not sure this has found its way into the 'Connection yet. Verify the pins do what they are supposed to with a multimeter before installation!

erich
 
I did have mine wired as per Bob. Went back to the wiring diagram from Emagair for simplicity. My power comes straight from the main bus through a CB (no switch), so it is basically wired as per their Emag wiring diagram.

I test the generater in the Pmag periodically by switching off all the power to the Pmag and slowly closing the throttle at the end of the flight. You can really only test one Pmag per start up this way but I dont find it necessary to test this function every flight.

This wiring system makes it easy to get into the setup mode. Previously (Bobs wiring) I had to run a seperate temporary ground wire (or instal another switch).

I find the factory wiring much better.
 
Keep it simple.....

If you still have not wired those P-mags up, you might want to give consideration to the way I have done it, which is essentially the E-mag way, but each P-mag controled by just one 2-50 switch, so it is ergonomically almost identical to standard mag switches.

For details see here.

When I looked at the Aero Electric approach it appeared to be trying to make extra, unnecessary complexity, but I forget the details. I think they changed their minds at least once after talking to E-mag who might know something about it.
 
Use Four Switches

Sonny,

I've wrangled with the P-mag switchology on three aircraft, coming to the conclusion and so modifying the current project to use four switches, individually supplying ship's power and grounding to the P-mags. Anything else means there is no way to function test each independently without causing a reboot to at least one - so invalidating its test.

Although E-mag never endorsed the Aeroelectric progressive switch method, the units survive, but they are not designed or tested for this operability per Brad. Grounding one to see if the other's working merely says "Don't make a spark", the unit is still booted. Then check the other. This way the you don't cut ship's power if low rpm, or drop out of self-power, so there is no rebooting while the engine is running, which is where one would depart from the design operability.

Now, it's off to LA behind two P-mags.

John Siebold
 
I used on/off switches for the P-mag. I installed 2 normally closed (spring loaded) push button switches for the power. Push to test.

Ken
 
NC push buttons

Where id you get these Ken..I have been looking for one to test the Pmag with

Frank
 
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