P-lead voltage rating requirement

[Isosceles]

Quick question - does anybody know what voltage rating is required for p-lead wires for Champion mags?

 

[Bell206]

Quick question - does anybody know what voltage rating is required for p-lead wires for Champion mags?

Voltage rating? Do you mean wire size? If so, most are 18 awg, shielded wire. Usually the wire size is called out for in an OEM wire diagram.

 

[Isosceles]

...Do you mean wire size?

I mean the voltage rating as in "insulation breakdown". Mike Busch says the actual voltage on the p-lead terminal is 200-300V (https://www.savvyaviation.com/how-mags-work/), but I would rather see a design requirement. Thinking of installing a connector in the p-lead wire to simplify mag timing check. My engine space is so tight that it is really hard to reach to the p-lead terminal without removing the air-oil separator and a bunch of hoses.

 

[Magman]

Some aircraft it’s easier to connect at the Switch.

 

[DreadPirateWill]

Most 18AWG Tefzel(MilSpec) is rated 600V. Personally I'd avoid adding a split in the P lead wires as it'd potentially introduce noise among other things, and complicate grounding the shield.

Some aircraft it’s easier to connect at the Switch.

Yep, I'd be looking at that - possibly making the switch easier to pull and attach leads to as needed.

 

[Magman]

Many aircraft have the switch near the bottom of the panel.

Remove external ring nut and it drops down.

Easy to check if AD’s apply too!

 

[Bell206]

Thinking of installing a connector in the p-lead wire to simplify mag timing check.

While I don't recall the voltage being that high (150v), as mentioned, the common MIL wire found on aircraft is rated to 600v or higher. However, I wouldn't recommend installing a 2nd connector in the system.

 

[AV8R_87]

However, I wouldn't recommend installing a 2nd connector in the system.

I second this opinion. You're adding an extra failure point that could lead to a hot mag or a non-functional one.

 

[Isosceles]

... extra failure point that could lead to a hot mag ...

Hmm... Connector failure is a theoretical possibility while in real life I did break off the p-lead by trying to connect the mag light in tight cowling space and noticed it only during runup before the next flight.

 

[AV8R_87]

while in real life I did break off the p-lead by trying to connect the mag light in tight cowling space and noticed it only during runup before the next flight.

Sounds to me like the post-maintenance inspection wasn't thorough enough. You're talking about a one-time event vs the possibility of vibration breaking that connection at any point during engine operation.

 

[Ed Haywood]

How about adding a pigtail from the mag to a more accessible location?

 

[Let'sgoflying!]

Thinking of installing a connector in the p-lead wire to simplify mag timing check.

I did this exact thing, for the reason you mention - works great.