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Surefly ignition question

togaflyer

Well Known Member
For those who have installed a Surefly in their -10, how did you run the power lead to that mag. It’s a lot of work running a wire from the battery to the fire wall. Is there other options?
 
I started with another option, but eventually changed to SureFlys recommendation. Here’s why…. I had it tied to power after master solenoid. Then, while on ground, experienced a short in a potentiometer switch that was smoking. If that had happened in flight, I would have lost SureFly ignition after turning master off. Take the time and do it as suggested. I agree it’s a pain, but it wasn’t as bad as I anticipated AND I feel better about avoiding unintended consequences.
 
I started with another option, but eventually changed to SureFlys recommendation. Here’s why…. I had it tied to power after master solenoid. Then, while on ground, experienced a short in a potentiometer switch that was smoking. If that had happened in flight, I would have lost SureFly ignition after turning master off. Take the time and do it as suggested. I agree it’s a pain, but it wasn’t as bad as I anticipated AND I feel better about avoiding unintended consequences.

I don't know anything about surefly, but I strongly agree that any electronic device required to make the engine work SHOULD NOT be run through the master. The master contactor is there to provide a method to stop an electrical fire at a time that you cannot get out of the plane. You do not want your engine to stop during this step. That said, it could be the EI that is causing the fire and I prefer a method to stop electron flow to it. Fuses will do that in the majority of issues that result in an electrical fire.

This is not really an issue if one mag is still there to keep the engine running.

Larry
 
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I again caution builders with ship power dependent engines to not be caviler about power distribution design. I also suggest that the install instructions for many of these systems should be considered “bare minimum”.

For example, if you can’t open your master(s) for smoke in the cockpit without loosing one or both ignitions, or for that matter anything on your panel needed for continued IFR flight (IFR ships) then I suggest a harder look at your design.

Carl
 
Apparently shorting when changing oil on the 10 is common. A 10Friend ran the wire to the battery, and put a higher value fuse at the battery and a lower value accessible under the cowl. The shorting has happened, and only took out the smaller value fuse. YMMV
 
In the Surefly install manual it says put the fuse as close to the mag as possible, but I was wondering why not a push/pull breaker located in the cockpit over an in line fuse. Also, how does changing the oil and an electrical short on the power line for the mag relate? I don’t see the connection.
And Randy, thanks for looking up what wire was used. It’s definitely a long run from the battery to the mag.
 
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Seems like the 14ga minimum and 10 amp fuse may be a bit of overkill for a unit that draws less than 1 amp.
Especially if your battery is on the firewall.
 
In the Surefly install manual it says put the fuse as close to the mag as possible, but I was wondering why not a push/pull breaker located in the cockpit over an in line fuse. Also, how does changing the oil and an electrical short on the power line for the mag relate? I don’t see the connection.
And Randy, thanks for looking up what wire was used. It’s definitely a long run from the battery to the mag.

Rich, section 2.7 of the airframe installation manual says this….

“Locate the 10A fuse (or other appropriate 10A circuit protection device) as close to the power source as possible.”

I think you want the fuse located on the battery end of the wire, not the SureFly end. (???)

Here’s how an oil change can blow that fuse. On an oil change I clipped my oil filter safety wire on engine side only for removal of filter. As I turned the filter for removal, the dangling end of that safety wire touched my SureFly hot terminal, blowing the fuse. Didn’t know it happened till runup for next flight. Now, I remove that fuse anytime I’m working in that area of my firewall. Keeps me from blowing a fuse if I accidentally touch the hot post with metal.
 
Rich, section 2.7 of the airframe installation manual says this….

“Locate the 10A fuse (or other appropriate 10A circuit protection device) as close to the power source as possible.”

I think you want the fuse located on the battery end of the wire, not the SureFly end. (???)

Here’s how an oil change can blow that fuse. On an oil change I clipped my oil filter safety wire on engine side only for removal of filter. As I turned the filter for removal, the dangling end of that safety wire touched my SureFly hot terminal, blowing the fuse. Didn’t know it happened till runup for next flight. Now, I remove that fuse anytime I’m working in that area of my firewall. Keeps me from blowing a fuse if I accidentally touch the hot post with metal.

I'll have this setup as well, and have a 10A Circuit Breaker on my panel for an Electronic Ignition.

Understand what the manual says - but assuming it is 'acceptable' to run an 'always hot' wire directly to the 10A CB on my panel, then to the Surefly module? At least I'd have the option to pull the CB for smoke, or when performing general maintenance around the module. I think an additional 'safety fuse' by the battery would be an unnecessary additional point of failure.
 
I'll have this setup as well, and have a 10A Circuit Breaker on my panel for an Electronic Ignition.

Understand what the manual says - but assuming it is 'acceptable' to run an 'always hot' wire directly to the 10A CB on my panel, then to the Surefly module? At least I'd have the option to pull the CB for smoke, or when performing general maintenance around the module. I think an additional 'safety fuse' by the battery would be an unnecessary additional point of failure.

Personally I think running a (long, in the -10) unprotected wire the whole cabin length is not acceptable. But ymmv.
 
Rich, section 2.7 of the airframe installation manual says this….

“Locate the 10A fuse (or other appropriate 10A circuit protection device) as close to the power source as possible.”

I think you want the fuse located on the battery end of the wire, not the SureFly end. (???)

Here’s how an oil change can blow that fuse. On an oil change I clipped my oil filter safety wire on engine side only for removal of filter. As I turned the filter for removal, the dangling end of that safety wire touched my SureFly hot terminal, blowing the fuse. Didn’t know it happened till runup for next flight. Now, I remove that fuse anytime I’m working in that area of my firewall. Keeps me from blowing a fuse if I accidentally touch the hot post with metal.

That wire is an extension of the + terminal of the battery that you protected with an insulation boot. Why wouldn't you protect the always hot terminal on the surefly.

The fuse should be within 2 inches of the + terminal of the battery. Surefly got the drawing wrong.... they should correct it and leave nothing to question on the installation......
sf diagram.PNG
 
14 ga wire

Yes, 14 ga and a 10 A fuse is suggested.
The current draw is less than 1 A, so 22 ga would work from an electrical point of view, if not to long wire. Allso a 2 A fuse would work for 1 A power draw.
However the mechanical strength of a 22 ga is not sufficient for this wire and
a 10 A will blow only on a short, not on a temporary overload.

Good luck
 
Personally I think running a (long, in the -10) unprotected wire the whole cabin length is not acceptable. But ymmv.

Sounds like I'll do both. (10A in-line fuse back by the battery, ran through my 10A CB so I can pull power if needed)
 
Ok that makes sense. I took a quick look at the Surefly diagram and it looked like the fuse was near the mag. Thought that was a bit weird having a unchecked hot wire. So if you kill the power to the Surefly does it loose programming or ? If you have a toggle switch or second breaker on the panel.
 
Ok that makes sense. I took a quick look at the Surefly diagram and it looked like the fuse was near the mag. Thought that was a bit weird having a unchecked hot wire. So if you kill the power to the Surefly does it loose programming or ? If you have a toggle switch or second breaker on the panel.

This was discussed at length in a recent thread. No programming is lost if power is interrupted.
 
Great info and thank you all. So since I need to go with a new harness I have contacted G3i and plan to get the auto wire kit with a Slick cap and convert over to auto plugs with the Surefly. So now I need to order some adaptors. When installing the plug adapters do you use anti seize on the adapter and the plug.
 
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