E-Mag/P-Mag wiring differences

[Mike Ice]

Hello,

I am going to have one each, E-mag/Pmag on my Lycoming O-320.

Has anyone else wired up this combination? I would sure like to know how you accomplished the switch wiring.

I am using the AeroElectric wiring diagrams, mostly the Z-11, but now I am combining the Z-13/8 with the application. But the 13/8 is for two P-mags. What I need to know and would like to know is how did you wire up the switches for the on/off combo.

Also: The the ignition switches shown in the Z-13/8 diagram then again in revision Z-33 have been reversed. In the Z-33 diagram the power from the main bus now enters the switch on the #4 leg instead of the #5. Is this correct or a mis-print?

Mike Ice
RV-9
Hanging the motor

[RV7Guy]

Hi Mike,

I had this combo. I now have two P mags. There is no wiring differences between the two. The only real difference is run your tach wire from the Pmag.

Wire your start switch per the instructions. Since I had one E and P, I had a breaker for the E and switched breaker for the P mag. If you are not there yet, use two switched breakers. Also wire each breaker individually with power and don't gang them together.

I used all 18 ga wire for the wiring. I'd have to check but I think I use 14 or 16 ga for the power run to the breakers.

This is one of the easier things to wire in the plane. Good luck.

[Mike Ice]

Darwin,

Thanks for the reply. I have already done the wiring for regular mags using the Aeroelectric Z-11 schematic. Each Mag had its own toggle switch and was fed power from the main bus.

I see that the P-mags require a different type of toggle switch than for regular mags. Also I see that the p-mags actually turn the switch around in the Z-33 revision. This is so that the P-mags can be have a maintenace positon where the mag is powered but not enabled (if I have that right).

What I am really curious about is two things.

1. Does the e-mag use just an on/off toggle switch?
2. Why are the switches wired differently in the Z-33 revision?

I did not use Van's standard switchable cb's. I have the blade type fuses in 3 separate buses. The start switch in my wiring system is a red push button.

Why did you switch to two P-mags? Perhaps I should do the same.

Mike Ice

[RV7Guy]

Hi Mike,

You have a little bit different set up. I used the ACS starter switch with L/R/Both positions. I used a standard 3 amp breaker for the Emag and a switchable 5 amp breaker for the P mag. The reason is, that you want to shut the power off the Pmag to establish the low idle point where the Pmag continues to generate power.

For the set up mode I turn on the Master switch and push the one breaker in and turn on the switch on the switched breaker. They are powered for set up now.

When I did my first year condition inspection I pulled the mags and sent them in for updates. Brad upgraded my Emag to a Pmag. I was content with the EMag.

I wouldn't bother to switch.

You'll have to work through the diagram to meet the needs of the PMag system. The individual switches are fine but you could make the switch breakers.

[Jekyll]

Mike:

I've got the same set up. Do you have a fax number? I'll fax my schematic to you. I'm on the road this week but I can fax it to you next weekend. Send me a private message.

Jekyll

[petehowell]

This is how I wired my E-Mag/P-Mag combo with hidden switch:



There are a few ways to skin this cat. Darwin is right, Tach signal off of the Pmag is best.

[Mike Ice]

Gents,

Thanks for the help. It is nice to know others have gone this way before. That is interesting that you got an automatic upgrade to a P-Mag. I wonder why?

Mike Ice