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Laptop trips GFI
Not unreal. For example, some leakage could be between
wires inside an electric box that become more conductive when humidity increases. Not conductive enough alone to trip a GFCI, but conductive enough when combined with leakage from the laptop. Also the battery charger was on - but was it charging when tests were conducted. All appliances have galvanic isolation. That means (in theory) low voltage circuits are isolated from AC mains - not leakage. In reality, even galvanic isolation has microamp leakage. I have even seen where a low voltage light causes just enough leakage to create rare and intermittent GFCI trips only when other appliances were powered just because a chipmunk chewed into insulation of that low voltage (and buried) wire. You have a battery charger on the circuit. How much is it leaking? The numbers, such as the normal leakage into safety ground wire where that safety ground wire connects to breaker box, are so important to those who would answer your posts. Again, what was humidity then verses today? How long since the last rain or a last boat hose down? And even what was powered from the battery when you were testing previously? Search for alternative circuits for current leakage - and that even includes the battery charger. GFCI says you have leakage somewhere. Now all we need do is find that leakage. Its easy to say - and so damn difficult to put into reality. Nothing unreal about your problem. Have solved these things so many times that I have no belief in ghosts. But then others long since give up before I do. My sympathies for your frustration and my envy for your challenge. JohnHH wrote: No, NOTHING was plugged into the computer. Certainly no NMEA devices. That said, I probably lied; I use a wireless mouse that MAY have been plugged in to a USB port every time. The laptop is a SONY VGN-A190 with Sony AC brick with a 3 wire plug. In a year of use, I cannot remember it ever starting up without tripping the GFI - EXCEPT TODAY! This is totally unreal. I came up to the boat this afternoon and made sure everything was turned off and nothing else plugged into the AC - only the ships battery charger was on, even the DC was off. I fired up the AC outlets and tuned on the computer, No fault. I turned off the computer, turned everything on and tried again. Still no fault I tried 4 times and can't cause it to fault. I'll try again in the morning after it has been off over night. |
#2
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Laptop trips GFI
Thanks for your feed back. I have been getting it to fail again by
unplugging the adapter from the wall, waiting a minute and plugging it back in. It seems like it happens far more consistantly if any other 110 appliance is running - like the refrigerator or heater or network router, but not 100% consistant. It's raining cats and dogs today so I am sure I have experienced it in every weather condition. By the way, my digital multimeter measures about 40 meg ohms before it goes to infinity. I am one of those who is going to give it up. I don't think it is serious and I'm losing interest. The problem will go away anyway when I replace the AC-DC converter with a DC-DC one. I'm not really frustrated, I was just curious. I fully expected someone to say, oh yea, that always happens with those power bricks. I'm going to bag this thing for now. Thanks to all of you who replied, it's been informative. John "w_tom" wrote in message ... Not unreal. For example, some leakage could be between wires inside an electric box that become more conductive when humidity increases. Not conductive enough alone to trip a GFCI, but conductive enough when combined with leakage from the laptop. Also the battery charger was on - but was it charging when tests were conducted. All appliances have galvanic isolation. That means (in theory) low voltage circuits are isolated from AC mains - not leakage. In reality, even galvanic isolation has microamp leakage. I have even seen where a low voltage light causes just enough leakage to create rare and intermittent GFCI trips only when other appliances were powered just because a chipmunk chewed into insulation of that low voltage (and buried) wire. You have a battery charger on the circuit. How much is it leaking? The numbers, such as the normal leakage into safety ground wire where that safety ground wire connects to breaker box, are so important to those who would answer your posts. Again, what was humidity then verses today? How long since the last rain or a last boat hose down? And even what was powered from the battery when you were testing previously? Search for alternative circuits for current leakage - and that even includes the battery charger. GFCI says you have leakage somewhere. Now all we need do is find that leakage. Its easy to say - and so damn difficult to put into reality. Nothing unreal about your problem. Have solved these things so many times that I have no belief in ghosts. But then others long since give up before I do. My sympathies for your frustration and my envy for your challenge. JohnHH wrote: No, NOTHING was plugged into the computer. Certainly no NMEA devices. That said, I probably lied; I use a wireless mouse that MAY have been plugged in to a USB port every time. The laptop is a SONY VGN-A190 with Sony AC brick with a 3 wire plug. In a year of use, I cannot remember it ever starting up without tripping the GFI - EXCEPT TODAY! This is totally unreal. I came up to the boat this afternoon and made sure everything was turned off and nothing else plugged into the AC - only the ships battery charger was on, even the DC was off. I fired up the AC outlets and tuned on the computer, No fault. I turned off the computer, turned everything on and tried again. Still no fault I tried 4 times and can't cause it to fault. I'll try again in the morning after it has been off over night. |
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