Have read most of the posts on wiring using 1 slick and 1 pmag. Have come to the conclusion that I will have to add 1 wire from the main bus via a switch to the pmag terminal 5. I used the Z-11 AEC diagram for my initial set up. I have two 2-5 momentary switches currently and have been starting with the left mag which has the impulse coupler. Do I still use the same switch to activate the starter contactor? Anyone else have a better wiring set-up with the two switches?
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Pmag wiring
- Thread starter rwarre
- Start date
N941WR
Legacy Member
First, start it on both ignitions. Or better yet, just start it on the P-mag. If it is a new P-mag with version 40, it will fire at 4 degrees past TDC until it sees 200 RPM. At that point, the timing will move back to the right place.
If you do not have V40 firmware in your P-mag and continue to start it on the magneto, your P-mag runs a VERY good chance of losing its timing mark. Firmware V40 solved this problem. (Older P-mags can be upgraded to V40. Contact Emag for details.)
If your timing is supposed to be 25 degrees, install the jumper (pins 2 & 3), which will force it to the A curve. If your timing is supposed to be 20 degrees BTC, you are going to want to adjust the timing map with Emag's EICAD program.
As for the wiring, make sure the ground wire coming off P-mag pin 1 is grounded to an engine case bolt. DO NOT ground it on the firewall or any other place!
Pin 5 needs a 12 volt power supply. Mine is protected by a 5A pullable breaker. Pin 4 is your P-lead and is what you use to "ground" the ignition, same as a P-lead on a traditional magneto.
How you wire and test your P-mag is up to you. Mine are wired with a three way toggle switch and the aforementioned 5A breaker. In my configuration, down is grounded and unpowered, the middle position is ungrounded and unpowered, and the full up position is ungrounded and powered. This allows me to check to make sure the internal generator is working properly as part of my preflight.
If you do not have V40 firmware in your P-mag and continue to start it on the magneto, your P-mag runs a VERY good chance of losing its timing mark. Firmware V40 solved this problem. (Older P-mags can be upgraded to V40. Contact Emag for details.)
If your timing is supposed to be 25 degrees, install the jumper (pins 2 & 3), which will force it to the A curve. If your timing is supposed to be 20 degrees BTC, you are going to want to adjust the timing map with Emag's EICAD program.
As for the wiring, make sure the ground wire coming off P-mag pin 1 is grounded to an engine case bolt. DO NOT ground it on the firewall or any other place!
Pin 5 needs a 12 volt power supply. Mine is protected by a 5A pullable breaker. Pin 4 is your P-lead and is what you use to "ground" the ignition, same as a P-lead on a traditional magneto.
How you wire and test your P-mag is up to you. Mine are wired with a three way toggle switch and the aforementioned 5A breaker. In my configuration, down is grounded and unpowered, the middle position is ungrounded and unpowered, and the full up position is ungrounded and powered. This allows me to check to make sure the internal generator is working properly as part of my preflight.
3 position switch
Bill, are you still happy with this configuration for your p-mags, the 3 position switch? Seems good to me, but wanted to confirm.
Wunderon
Well Known Member
Using a 2-50 for the pmag as Andy is here (right ignition in my case)
http://www.vansairforce.com/community/showpost.php?p=846885&postcount=16
http://www.vansairforce.com/community/showpost.php?p=846885&postcount=16
N941WR
Legacy Member
Yes, it has worked out very well.
Please make sure you ground the P-mags correctly. P-mag Pin #1 should go to its own case bolt and make sure to remove any paint that might be under that bolt. Poor grounds are one of the biggest issues we see.
I also recommend that anyone installing a P-mag bring additional wires in from P-mag pins #1, 2, & 3 into the cockpit. (And #6, if you think you are going to add an EICommander at some time.)
That way you can tune your P-mags from the cockpit without having to remove the cowl vie the Emag EICAD program.
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