She caught fire today

[bytecode77]

She's hot, obviously...

But today her primary coil cought fire!
I covered the secondary coil in translucent tape in order to prevent flashovers. But they're still there, see the video: http://webmshare.com/play/6MAWD

After approximentaly 30 minutes of running, the volume dropped as the primary winding started burning so I had to blow out the damn fire! Then, the circuit breaker tripped.

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(1.08 MiB) Not downloaded yet

• So, Even though I taped the secondary, I still got not only flashovers, but strikeouts from certain spots of the secondary. Was it too damaged already?
• What happened to the primary? I thought it was ok to run longer than a few minutes. Was it maybe the super glue that leaked all over the primary coil when I glued it together?

[Heidi]

Oh no! That sounds bad. It looks like you were getting arcing directly to the primary, which burned the insulation. I've never seen extended run times make the primary get hot enough to burn; you'd probably see the wire melting off if this were the case.

Tape is a good insulator, but you have to be VERY careful about not trapping any air underneath the tape, because otherwise you get flashover underneath it. There's a huge difference between a good tape job and a bad tape job, but from what I see in your photo it looks alright. How many layers of tape did you use? I've had about 3 do the trick.

Also, whenever you have compromised insulation you need to deal with it IMMEDIATELY! It's not going to get any better with time.

You may want to flip your secondary so that the burny bits are on the top and no longer near the primary. Also, take a file and round off your primary clips.

[bytecode77]

Thank you for your tips! I think you covered everything I made wrong. At first, I sprayed the secondary with clear coat, which didn't prevent all of the flashovers. So after some time, I decided to tape it. I only used one layer and I also trapped air underneath it, which caused the sparks inside the secondary.

However, I can't just turn it upside down. It has lots of burned spots as seen on the screenshot. This is the second secondary coil I wasted. I already posted an order to you via email with everything that got destroyed here. Also, from now on, I'll definitely not leave her unattended again

Any more suggestions on how to prevent fire and flashovers next try are very welcome!

[Alex]

every flashover will deteriorate the insulation. there could have been a place where the primary was burnt through, but you weren't able to see it because it was on the inside of the coil and your insulation was black. I've had a primary coil burn through and not be able to run without just spewing arcs everywhere.

just run it conservatively and avoid flashovers at all costs.

[pierrepaul]

Hello,

it is not beautiful
to prevent lightning between the primary and the secondary, I use a special ground
She is not connected to circuit breaker but with aluminium paper.

it works even with low song

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[bytecode77]

What does an aluminium floor plate have to do with flashovers?

[pierrepaul]

hello,

sorry, I misspoke I have not finished my sentence

I had the same problem flashover by connecting the secondary grounding of the house, however, there has been the problem in the first test

this plate being connected to an external ground that flashovers the ground circuit of the house, I noticed that the flashover had disappeared.

[Alex]

ah yes if you have a poor ground you will get nasty flashovers.

[pyrowolf]

I use a 60mm plexiglass tube to cover the whole secondary coil. It fits perfectly and i never have any flashovers. I made a flat 5-turn primary and have 20-22" sparks. Primary gets only slightly warm and igbts also stay pretty cool. I run the coil for up to one hour without issues. The plexi tube does a really cool job, and i even painted it black inside .


Short video of the coil:

http://youtu.be/-0CZbzvHCTw

Cheers,

Wolf

[bytecode77]

Interesting custom design you have there. I'm way to untalented on handcrafting. Luckily, I bought an already insolated secondary coil from oneTesla and other replacement parts that also got destroyed.