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Am I being electrocuted?
Posted by Jesus Ali on June 20, 2008 at 2:31 pmHello Everyone,
I have recently purchased a KONA 3 for the school I work for and have been
playing with itanalyzing workflow systems for the Fall.I connected the card to the breakout cables and then to a studio monitor and HD-SDI connection from a Canon XL H1.
I’m not certain, but it felt like my fingers were gently tingling while I was handling the breakout cables.
Yes, the computer and card were both on while I was making the connections. 🙁
Is there any chance that a current could run through the BNC “sleeves” (knurled knobs) of the breakout cables? My assumption would be that all of the sleeves are Ground and the pins would be Live.
I looked closely and didn’t see any shorts where the pins would be touching any of the sleeves.
• Do you think I was actually feeling any current or is my imagination just getting the best of me? Maybe the “electricity” in the air was only my excitement? 😉
• How hardily do people recommend the rack mount breakout box for the KONA 3? Who considers it a necessary accessory? Do you think it is naive/dangerous not to use it?
Thanks as always, Jesus
Ramona Howard replied 17 years, 10 months ago 6 Members · 14 Replies -
14 Replies
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Bob Zelin
June 20, 2008 at 6:54 pmHi Jesus –
if you are feeling “tingling” from touching the cables, you have a AC power ground fault at your school, which is a dangerous situation. You need to have a professional licensed electrician come in to check the AC outlets in your entire facility. If you do nothing, at best, you will observe severe hum in both the audio and video signal..Bob Zelin
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Gary Adcock
June 21, 2008 at 1:45 pm[Jesus Ali] “Yes, the computer and card were both on while I was making the connections. 🙁 “
Jesus….
how many post have you read on the Cow about people blowing up their computers while connecting devices?In earlier versions of the computer you stood a very good chance of blowing out your logic board by connecting anything direct to a PCI card. Just like the numerous people here that have blown out the FW ports on their systems by plugging in devices when powered up.
gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD -
Aaron Neitz
June 25, 2008 at 5:52 pmHere’s one for you…
Was overseas, 220/60Hz (tahiti). Had a travel converter. Plugged my iPhone charger into converter. You could feel that tingly sensation on all the metal parts of the iPhone when it was plugged in.
I’ve experienced grounded faults in the States before (as well as straight up elextrocution :), and that’s exactly what it felt like. But the iPhone charging over USB? That was odd. It charged, however, and everything works fine.
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Bob Zelin
June 25, 2008 at 10:13 pmthis is why grounding is a requirement in the United States and Europe. Faulty grounds can be potentially dangerous, and even deadly if miswiring happens. An electrician that runs power to the ground of one circuit (from miswiring) may seem like a tingle, but if you touch that “ground” and the true ground from another circuit or equipment chassis, you will have 110VAC (or 220VAC in Europe) sent thru your body, from hand to hand.
And just for the record, this is called “electric shock”, not electrocution. If you are electrocuted, you are dead. I found this out from a hospital emergency room, where an employee of mine in NY cut into an AC power cord by accident, while having his other hand on an equipment chassis. (He’s not dead, so this was electric shock).
bobZelin
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Jesus Ali
July 1, 2008 at 5:09 pmYes Gary, I know my behavior was sketchy… 🙁
But just to be clear, if I was using the KONA 3 breakout box should I STILL power down the computer completely before changing any connections? Is that the recommended “best practice” even with the box?
Would you recommend the same caution with an IoHD box? Shutdown everything before changing any connections?
I suppose it won’t be such an issue once the edit stations are setup, I’m experimenting with different configurations now though, so I’ve been swapping things out a lot.
But if I should tell students to shutdown completely before switching anything I will.
Thanks. Jesus.
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Jesus Ali
July 1, 2008 at 5:13 pmIf any of you KONA card owners have a moment, could you tell me if you are or are using the breakout box?
Any arguments pro or con would be appreciated. I’ll have to sell the school funders on the additional purchase.
Could people also recommend a nice, small, “mini rack” to put the breakout box into? Right now we don’t have a professional edit station desktop with rack mounting holes. Is anyone using something to hold the breakout box on a desktop or on top of the Mac Pro?
Any thoughts and tips would be welcomed.
Thank you. Jesus.
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Gary Adcock
July 1, 2008 at 5:40 pm[Jesus Ali] “But just to be clear, if I was using the KONA 3 breakout box should I STILL power down the computer completely before changing any connections? Is that the recommended “best practice” even with the box? “
I am NOT talking about BNC’s
the discussion was about attaching directly to a card – and NO never attach any of the outboard connections to ANY installed PCI card while the power is on,
that includes the Kbox or tether and anything like SCSI, SATA, FIBRE –all can have issues. It only takes one mistake to blow out the logic board and they are not covered under most warranties for operator error.
“Would you recommend the same caution with an IoHD box? Shutdown everything before changing any connections?”
NEVER connect the IoHD to any Computer with the IoHD powered up
there is power and signal over that FW bus it uses – it is a computer after all, not a dumb drive waiting for instruction- and it will blow out the logic board if you are not careful.
gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD -
Gary Adcock
July 1, 2008 at 5:50 pm[Jesus Ali] “Any arguments pro or con would be appreciated. I’ll have to sell the school funders on the additional purchase.”
the single best reasons for the Kbox in a school environment would be less wear and tear on the tether, less chance of damage to the back of the computer due to student error.
The Kbox connections are hardened in a 1RU space to take the wear off the cabling.
I have one of in a small 8RU location rack that I got at a music store for under $125.The other thing to do is use the “ears” on the rack and cable tie it to a hole in the desk.
gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD -
Walter Biscardi
July 1, 2008 at 6:53 pm[Jesus Ali] “If any of you KONA card owners have a moment, could you tell me if you are or are using the breakout box?
Any arguments pro or con would be appreciated. I’ll have to sell the school funders on the additional purchase.”
We only use the breakout box on all our Konas as it’s just a lot easier and more robust than a snake of cables.
Walter Biscardi, Jr.
Biscardi Creative Media
HD and SD Production for Broadcast and Independent Productions.STOP STARING AND START GRADING WITH APPLE COLOR Apple Color Training DVD available now!
Read my Blog!

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Jesus Ali
July 1, 2008 at 9:15 pmOh, Gary, the “connections” I was referring to in my original post were the component sides of the BNC Tether. I wasn’t plugging in the Tether (DVI-type) Connector or the mini BNC’s with the computer powered up. I’m not that reckless!
I was connecting the SDI In 1 to a camera and the Component BNCs to a studio monitor. That’s when I felt the tingling, as I was sorting out the BNC’s from the XLR connectors.
And that was my question about the IoHD. And subsequently, the KONA 3 breakout box.
Can those BNC connections be changed while the unit is powered up?
Thanks for music store rack mount tip. I will take a local look.
Thanks. Jesus.
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