Request for one of our Wizards help to explain a High-voltage shock on a 12 volt system.

[All_In]

Dave Bacon and I are rewiring an ARGON 915 wiring system. That the owner paid 5K for a week (5 days) of A&P's time.
It was a spaghetti mess. The fuel pumps had no fuses or independent breakers.

The most difficult problem we just discovered a day or so ago. The front what I believe now must be strobe lights come on as soon as you turn on the main switch. But they are mostly on. Only notice that they actually blink off then back on for a very LONG time then blink off. But it has no timing pattern in minutes. Might be 30 seconds or a few minutes and when no one is in it or near it we are not touching any wires unless it is a ghost.

I first thought it was a loose or shorted wire but after pulling on the actual wiring it made no difference.

The clue that they are a strobe that has lost its resistor pack timing but not its capacitor is that Dave got shocked through the conductive carbon fiber body while working under the fuselage on a 12-volt system. (Better him than me) HahahahahahHehehehehehe. Craked me up, Dave did not see the humor.

Does anyone know on an ARGON 915 if she has always on strobe lights in her nose next to the spot landing lights?
They look like long LED bars.
Somewhere there is a capacitor that is being charged to a higher voltage than 12 volts??? Help Wizards... Need input?

 

[DonBishop]

What a shocking experience. I'll bet Dave was amped up.

 

[All_In]

Hi Don.

Still laughing over that one.

 

[All_In]

You can see the long thin lights on each side of the spot landing lights. This is the best picture I could find...

 

[Vance]

At the risk of stating the obvious; in order to “rewire” anything you need to label everything, not just the things that are causing the problems or you will have more problems as soon as the aircraft begins to shake.

Follow the wiring diagram.

Tidy up everything with generous service loops.

 

[All_In]

At the risk of stating the obvious; in order to “rewire” anything you need to label everything, not just the things that are causing the problems or you will have more problems as soon as the aircraft begins to shake.

Follow the wiring diagram.

Tidy up everything with generous service loops.

Yes sir. That is what we recognize needed to be done and are in the process of doing now.
Basically, I cannot see where the wires were going all tangled together.
Now 75% are neatly bundled together after testing where every wire is connected verifying it with the wiring diagram.

The problem with the drawing none of the lights are drawn with electronic symbols or I could tell a strobe light from a LED or a panel light. Just a circle labeled light.

 

[All_In]

I suspect the IIRC "Philps" black/box connector box. It has room for electronics inside of it and appears too big to only hold 3 plug-in light connectors. I will take it off the carbon fiber first and see If I can get dave to try and shock himself... I expect to fail at that request so need to contact the compnay next.

 

[DavePA11]

Can’t help with any advise, but can share the pain. I tried to fix some wiring on mySportcopter, but then end up pulling it all out and rewiring it with aviation grade wire, connectors, etc... Took a while, but got everything working including eliminating the radio noise.

 

[All_In]

Can’t help with any advise, but can share the pain. I tried to fix some wiring on mySportcopter, but then end up pulling it all out and rewiring it with aviation grade wire, connectors, etc... Took a while, but got everything working including eliminating the radio noise.

Thank you, Dave. Believe it or not, sharing my pain helps, not sure why.

 

[C. Beaty]

You get shocked by a 12 volt electric system from the same phenomenon that permits you to generate the several thousand volts required to fire spark plugs; an inductor with a collapsing magnetic field. When the points open, the magnetic field in the ignition coil collapses and the resulting collapse or motion of the magnetic field generates high voltage in the ignition coil. The condenser acts like a flywheel, it slows down the rate of collapse, allowing time for the points to gain a bit of separation before the high voltage appears. What could be simpler?
When you tinker with the aircraft wiring, you;'re doing the same thing.

 

[All_In]

You are correct my friend. I did not start to even think in those simple terms until you mentioned it. Carbon fiber can hold even a static charge if you rub it enough. Or so I've read. I've not tested it yet.

Oh, Dave, I have an experiment with a buffing wheel building up a static charge for you to test for me.
Dave, Dave, where did Dave go?

 

[All_In]

At the risk of stating the obvious; in order to “rewire” anything you need to label everything, not just the things that are causing the problems or you will have more problems as soon as the aircraft begins to shake.

Follow the wiring diagram.

Tidy up everything with generous service loops.

Bro... Out of fairness to the company. 95% of the wires were prenumbered/or labeled with their reference text that matches the drawings. That part was mostly done.

PS:
It's the A&P that made the mess, but again out of fairness, we have not found anything hook up incorrectly. Only no fuses to IIRC the most draw there is. The fuel pumps were directly wired to switches. They now each have their 20 Amp breakers right by the switches.


WARNING this is hearsay, but reputable hearsay = BTW we were warned that Rotax now has or is about to issue a 40-hour failure warning on the 915's fuel pumps!!! CFI, FBO, Craig Mc Pherson (spelling?) IIRC had two, maybe more, fuel pumps burn out at 40 hours.

 

[chrisk]

Below is the schematic for the Whelen strobe. I have not studied the schematic, but I believe it probably works by building a magnetic field in the transformer, then the timer pulses the input on the primary side. This causes a high voltage pulse on the secondary winding on the transformer, which is fed to the neon bulb. Its not a traditional capacitor. The power supply in your laptop is not really all that different, except it is a step down.

 

[All_In]

Math and schematics are the only languages you cannot misunderstand!
I see said the blind man!
Thank you Chris

 

[StanFoster]

Tell Dave that though a good electrician may get shocked once in awhile, he should always do it without shorts.

 

[JEFF TIPTON]

John

Check the PDF for the voltage

 

[All_In]

Tell Dave that though a good electrician may get shocked once in awhile, he should always do it without shorts.

No way I'm telling Dave that while he is working with ME.
He might do it!
Miss you at every fly-in. They have never been the same!!

 

[All_In]

John

Check the PDF for the voltage

That was very helpful!!!
Bro, U-ROCK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[All_In]

Think I've figured this out. Only need to go to the airport and test it.

Thank you all for the education needed!

I love this forum because you spent the most valuable thing you all own, TIME, to help others save weeks of research to learn anything they need to know.

Well except maybe for where to buy RAF Euro 90 degree Intertubes?

 

[Abid]

Dave Bacon and I are rewiring an ARGON 915 wiring system. That the owner paid 5K for a week (5 days) of A&P's time.
It was a spaghetti mess. The fuel pumps had no fuses or independent breakers.

The most difficult problem we just discovered a day or so ago. The front what I believe now must be strobe lights come on as soon as you turn on the main switch. But they are mostly on. Only notice that they actually blink off then back on for a very LONG time then blink off. But it has no timing pattern in minutes. Might be 30 seconds or a few minutes and when no one is in it or near it we are not touching any wires unless it is a ghost.

I first thought it was a loose or shorted wire but after pulling on the actual wiring it made no difference.

The clue that they are a strobe that has lost its resistor pack timing but not its capacitor is that Dave got shocked through the conductive carbon fiber body while working under the fuselage on a 12-volt system. (Better him than me) HahahahahahHehehehehehe. Craked me up, Dave did not see the humor.

Does anyone know on an ARGON 915 if she has always on strobe lights in her nose next to the spot landing lights?
They look like long LED bars.
Somewhere there is a capacitor that is being charged to a higher voltage than 12 volts??? Help Wizards... Need input?

Fuel pumps for 915 have fuses in the Rotax supplied fuse box. You don't need to put other fuses on them.
I can't even understand the rest of your issues so I can't help.