Originally Posted by birddog486
Mark, do you have a diagram how these are wired. I'd like to copy this when I wire up my pmag.
I don’t have an actual diagram but basically all I’m doing is using the middle (#2) position as “on”. Then I’m grounding “killing” the ship/battery power in the (#1) (off position). Then grounding “killing” the self generating power lead in position (#3)...the momentary position. So here’s the sequence:
1. Flip both switches from the (#1/off) position to the (#2/on) position.
2. Start the engine.
3. At engine idle move one of the switches back down to the #1/off position while leaving the other switch in the #2/on position. This is checking ship/battery for the opposite mag. If the engine keeps running you’ve now confirmed that the engine will run on one mag/ship power on that one particular mag. Repeat this step with the other switch in the off position. You’re now confirmed that the engine will run on each individual mag/ship/battery power.
4. Now, with both switches in the middle (on/run) position, run your RPM’s up to about 1500. Move one of the switches to the (#1/off) position and move the other switch into the (#3/off/momentary) position. You’ve now killed the battery power lead on one mag and kill the p/lead (self generating power) on the other mag. The engine is now running on one mag/self generating power. Now, move both switches back to the middle position and repeat with the opposite switches. You’ve now confirmed that the engine will run one only one mag while generating its owner power...(no ship/battery power).
5. Finally, confirm that both switches are back in the middle/on positions and you’re now ready for flight. It takes less than 10 seconds to perform a complete test.
Like I’d mentioned in my previous post, my switches have a lockout between the #1/off and #2/on positions. This prevents me from inadvertently moving either switch back into the #1/off position. If one or both switches were to accidentally be moved into the #1/off position, it would continue to run just fine while your flying, but when you slow down for landing, and if both switches were in the #1/off position, the engine would die because you’re not generating self power and you’ve killed your battery power. If I were to accidentally bump a switch up into the #3/momentary position while maybe flying through turbulence, it’s not a big deal because it’ll immediately return to the #2/on position on its own. In your case I think you’d said that you’re planning to use only one p/mag, but you’d basically go through the the same sequence to check the one p-mag while killing power to your regular mag.
I hope this helps you out a little bit.