Electricity shock from Hasselblad Camera, tethered

[yaya]

What happens when you unplug the laptop from the mains power?

[jerome_m]

I'm on a job in Thailand actualy. 220v. the buildings are of different age.
As far as I know between the laptop and the power plug, the apple charger has a transformer.

Your Apple charger has tiny prints on it. Somewhere it says "Input" and then some. If it says "Input 100-240V" (like mine), you don't need a transformer.

What happens when you unplug the laptop from the mains power?

That is a good question. Additional question: do you have anything connected to the computer and to the mains as well (e.g. an external drive)?

[orc73]

Yes I was thinking about unplugging the laptop to try what happens, that will not be a solution for the imac or computers in commercial studios.
Attached to my macbook is usually a wacom. Attached to that imac was usb drive.

[jerome_m]

Attached to my macbook is usually a wacom. Attached to that imac was usb drive.

The Wacom digitiser is not connected to the mains (unless it is the one with a display...), so it does not count. The USB drive will only count if it has its own power supply, connected to the mains.

[Plateau Light]

You have to understand that the feeling/sensation the OP is mentioning is from higher voltage AC. This is distinctly different from the low-voltage DC that is in the cabling of your devices. It is possible there is a ground loop from plugging into different outlets with a different ground potential.The only time I had ever been shocked when using your camera was when the polarity of the sync cord was backwards and the high-voltage AC in the trigger was bleeding through

[eronald]

I understand that the OP has a problem, and at this point he seems to be lining up for a Darwin award.

"Photographer in Thailand complained about getting shocks from his camera and fetched rubber shoes which made shocks disappear. Then to take perspective shots, he placed metal step ladder on metal drain, and held camera in one hand while grasping ladder rungs in the other. Ambulance arrived late and were incapable of reanimating."

I may not be much of a photographer but I do know something about electricity. I strongly urge the OP to stop posting and go seek professional assistance.

BTW what usually kills people AFAIK is the fact that they suffocate because their lung nerve input has been overloaded by the 50Hz AC frequency. It doesn't take much of a current to do this.

Edmund

You have to understand that the feeling/sensation the OP is mentioning is from higher voltage AC. This is distinctly different from the low-voltage DC that is in the cabling of your devices. It is possible there is a ground loop from plugging into different outlets with a different ground potential.The only time I had ever been shocked when using your camera was when the polarity of the sync cord was backwards and the high-voltage AC in the trigger was bleeding through

[orc73]

ok I might be a photographer and I made be stupid.
So if you are so much cleverer I'm sure you are able to give advice in a way so also the most stupid guys understand, right?
And that's why we have forums, because some guys know things or have experience about things, other guys don't have.

It's never a shame to ask questions, it is a shame not to ask and do stupid things.

To keep in the topic, it seems there are problems with electricity in Thailand in general as I found out. Grounding problems usualy.
Now calling a professional will not help. He will know as much about electricity as your grandmom, and just lucky enough, never got hit to strong so he can still work in this job. Besides they will not change the cabling in the house, because some foreigner has an electricity problem.
What can I do?

[Jim Kasson]

What can I do?

Track it down. But you've already rejected my suggestion to start probing around with a voltmeter, saying you don't need it because you can feel the shock.

I dont need a volt meter, i can feel it burning.

There's an electrical potential developing. You need to find out what parts of your studio are at the same potential, and what parts  are at different ones. Make a map. I bet you'll find a clue there. However, you can't do that without a voltmeter, and you say you don't need one to solve your problem. So I'm out of ideas.

One thing you might do to help us troubleshoot the problem is post some pictures of the studio and setup.

One thing you might do to help yourself solve the problem is run a wire from the ground of the outlet the sompute is plugged into to where you're taking the picture and touch the ground and see if you get a shock. Let me be clear that I think this is dangerous and inexact, and that I recommend the -- now rejected -- voltmeter.

Jim

[orc73]

@Edmund: besides even obviously get fed intelligence on the baguette you don't need to talk to the other forum member about the OP and make jokes. As you can see the OP can read himselves a bit too. so you can adress directly with your  constructive suggestions.

[orc73]

thanks Jim for your concrete formulations, you might be right about the voltmeter, I just will not be able to interprete the results.
As for the plan I don't really have much to plan, there is a plug in the wall, a cable to the computer, and a firewire to the camera.

For dummies:
As far as I can follow you, in this plan, the problem must be in the wall. to be precise in most walls of thailand.

Even if I could get it fixed in my home, I will have the problem in every location.

[Jim Kasson]

thanks Jim for your concrete formulations, you might be right about the voltmeter, I just will not be able to interprete the results.

Show us pictures of the studio with circles and arrows and explanations. Show us the outlet the computer is plugged into. Show us where you're standing. We'll suggest places to do measurements. Tell us what they turn out to be. Maybe we can do this by remote control. Is there no one available who knows anything about electricity?

Jim

[orc73]

I certainly won't get any circuit plans.here is one location, the 2nd one looks similar. except the macbook is replaced with an imac.
I forgot to draw the hdmi cable to the monitor.

[Jim Kasson]

I certainly won't get any circuit plans.here is one location, the 2nd one looks similar. except the macbook is replaced with an imac.
I forgot to draw the hdmi cable to the monitor.

Good diagram. How about some photos?

Jim

[eronald]

I am not going to tell you to setup experiments with wires between your equipment and anything else because my feeling is that such experiments could kill you and I don't think that would be funny.

There are always competent guys at electric utilities and larger installations like big hotels - something like a $20 bill should cover an hour's work for a guy and his tools, over in Thailand.

Edmund

@Edmund: besides even obviously get fed intelligence on the baguette you don't need to talk to the other forum member about the OP and make jokes. As you can see the OP can read himselves a bit too. so you can adress directly with your  constructive suggestions.

[orc73]

Thanks Edmund, I'm also not able to classify if the danger of the situation.

an answer like "Dude your life is in danger, don't tether in that country anymore" would be discouraging but clear

[eronald]

Orc73,

I'm sorry for any inappropriate language. I think your life may be in danger. The only way you can tether safely is with no external screen ( HDMI wire unplugged) and with the computer and camera running off battery power, all power adapters completely unplugged from camera and computer.

 

Edmund

PS. There are intuitive guys and systematic guys. I can do the systematic calculation stuff, but basically I'm mostly intuitive. There is something about your story and the installation diagram which I simply don't like.

Thanks Edmund, I'm also not able to classify if the danger of the situation.

an answer like "Dude your life is in danger, don't tether in that country anymore" would be discouraging but clear

[jerome_m]

I certainly won't get any circuit plans.here is one location, the 2nd one looks similar. except the macbook is replaced with an imac.
I forgot to draw the hdmi cable to the monitor.

From this plan, I strongly suspect the Dell screen. I may be wrong, of course.

[eronald]

From this plan, I strongly suspect the Dell screen. I may be wrong, of course.

The guys in aviation call this the swiss cheese - normally nothing can fall through, but if the holes suddenly line up - bang!

Yes, one path for the leakage might be via the HDMI from the Dell screen - that's one hole -, but of course there should be no real path to anything live on that HDMI cable so something would need to be wrong on the Dell side -second hole-  which may mean that the screen has a fault or the ground of the Dell is already live, which it may already be because it is live at the outlet etc etc.

I don't like this whole setup. Sorry. One more hole that lines up and there may be a real life-threatening issue. Which is why I am clearly telling Orc 73: "Dude, please stay away from this".

Edmund

[BobShaw]

Sounds like the charger is faulty and leaking earth to active, (or you are using a faulty extension cord).
Is it non genuine, (meaning it wasn't new with the computer as non genuine ones can still be marked Apple)?

[orc73]

Ok after some research basically there is electricity "leaking" everywhere in this country and nobody want's to do shit about it.
Be aware of that if you ever travel here.

Anyway it is not camera related then. Thanks for everybody who was trying to help!

Even when working on the computer, as soon I touch the metal ladder next to me that goes up, it will transfer. In Fact the USB Wacom having the worst effect(even when the laptop is not connected to the charger), the dell also has strong effect, unplugging everything reduces the problem.
I could never have imagined, the wacom tablet could have this influence. Especially I can't imagine where the power comes from then, as the laptop battery is the only source in this case. Or the ladder gets it somewhere.