- Feb 22, 2007
- 16,240
- 7
- 76
I just got a call from the wife of a friend who was doing something in his basement and got shocked pretty bad, bad enough that his wife called rescue. His monitor shocked him, but not how you might think.
I finally got him on the phone to find out the details.
He said he thought he would be ok, but he's got a pacemaker and they want to make sure.
He was repairing a switch mode supply for a server and didn't have a large enough isolation transformer so he ran it hot.
While measuring some points with the oscilloscope he reached up to turn the monitor to get a better view at the schematic he had displayed.
Thats when ge got shocked, bad enough he said he saw sparks.
He didn't understand what happened and neither did I.
He works while standing on rubber matts and so I asked him did his left arm brush against anything while he was holding the probe with his right ?
He said no, and I trust him, he's well versed on safety and always works with his left hand at his side. So I pulled out my meter here and started to check out something.
If you got a crt monitor, read on.
The coating thats on the monitor might be grounded to the AC socket.
I checked several crt monitors I have and all of them show a connection to ground. Before this I thought they were merely plastic films or spray on coatings or at most maybe a small metal content, and certainly not connected to the main monitor ground. But it appears after some google searches thats not the case.
I never would have seen this coming.
I finally got him on the phone to find out the details.
He said he thought he would be ok, but he's got a pacemaker and they want to make sure.
He was repairing a switch mode supply for a server and didn't have a large enough isolation transformer so he ran it hot.
While measuring some points with the oscilloscope he reached up to turn the monitor to get a better view at the schematic he had displayed.
Thats when ge got shocked, bad enough he said he saw sparks.
He didn't understand what happened and neither did I.
He works while standing on rubber matts and so I asked him did his left arm brush against anything while he was holding the probe with his right ?
He said no, and I trust him, he's well versed on safety and always works with his left hand at his side. So I pulled out my meter here and started to check out something.
If you got a crt monitor, read on.
The coating thats on the monitor might be grounded to the AC socket.
I checked several crt monitors I have and all of them show a connection to ground. Before this I thought they were merely plastic films or spray on coatings or at most maybe a small metal content, and certainly not connected to the main monitor ground. But it appears after some google searches thats not the case.
I never would have seen this coming.
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