Laptop trips GFI

Good idea, I'll try that.

"Larry" wrote in message

> If it has 3-wire grounded plug on it, plug it into a ground buster and see
> if it stops. The input filters on some of the switching supplies allows
> enough AC to ground pin to trip them. I've had some ground loops trip
> mine
> here at home from certain printers plugged into the outlets on other
> circuits than what the computer is plugged into.
>
> "johnhh" wrote in
>
>
>> All of my 110 outlets on the boat are protected through GFI. Whenever
>> I plug my laptop charger in or turn on the computer with it plugged
>> in, it trips the GFI. If I reset it a time or two or three, it will
>> hold and work fine until the next time. Interestingly, it will even
>> trip the GFI on a parallel circuit. I am guessing that it has
>> something to do with the large capacitor in the charging unit charging
>> up. Does anyone have an explanation and/or solution?
>>
>> thanks
>> john
>>
>>
>>
>
>
>
> --
> Larry
 >> Stay informed about: Laptop trips GFI 

Obvious questions:

I assume you have GFI outlets and not a GFI breaker.

Anything else plugged in to that outlet when the computer trips the GFI?

Is anything else plugged into the laptop when the GFI trips? SSB? radio?
printer? NMEA stuff?

Have you tested the GFI with the "test" button?

Have you tried the laptop in other GFI outlets?

The only thing that is supposed to trip one is a differential current in
the hot and neutral wires. The unequal current is almost always because
the appliance has found an additional return path through its grounding
conductor back to the service entrance. If such a problem exists with
your laptop, it should be corrected. Alternatively, a new GFI outlet
might cure the problem.

Good luck!

Chuck

johnhh wrote:
> All of my 110 outlets on the boat are protected through GFI. Whenever I plug
> my laptop charger in or turn on the computer with it plugged in, it trips
> the GFI. If I reset it a time or two or three, it will hold and work fine
> until the next time. Interestingly, it will even trip the GFI on a parallel
> circuit. I am guessing that it has something to do with the large capacitor
> in the charging unit charging up. Does anyone have an explanation and/or
> solution?
>
> thanks
> john
>
>
 >> Stay informed about: Laptop trips GFI 

Thanks, it's the laptop and only the laptop. The only thing I haven't tried
yet is another GI outlet. I need to remember to bring the thing home to do
that. At any rate, it is only a minor inconvenience that will go away after
I wire up the 12v supply I have for it. I just find it curious.

John

"chuck" wrote in message

> Obvious questions:
>
> I assume you have GFI outlets and not a GFI breaker.
>
> Anything else plugged in to that outlet when the computer trips the GFI?
>
> Is anything else plugged into the laptop when the GFI trips? SSB? radio?
> printer? NMEA stuff?
>
> Have you tested the GFI with the "test" button?
>
> Have you tried the laptop in other GFI outlets?
>
> The only thing that is supposed to trip one is a differential current in
> the hot and neutral wires. The unequal current is almost always because
> the appliance has found an additional return path through its grounding
> conductor back to the service entrance. If such a problem exists with your
> laptop, it should be corrected. Alternatively, a new GFI outlet might cure
> the problem.
>
> Good luck!
>
> Chuck
>
> johnhh wrote:
>> All of my 110 outlets on the boat are protected through GFI. Whenever I
>> plug my laptop charger in or turn on the computer with it plugged in, it
>> trips the GFI. If I reset it a time or two or three, it will hold and
>> work fine until the next time. Interestingly, it will even trip the GFI
>> on a parallel circuit. I am guessing that it has something to do with
>> the large capacitor in the charging unit charging up. Does anyone have
>> an explanation and/or solution?
>>
>> thanks
>> john
 >> Stay informed about: Laptop trips GFI 

"johnhh" wrote in
iA.RemoveThis@comcast.com:

> I need to remember to bring the thing home

Oh, oh....needs attitude adjustment....

The laptop IS already home. You just need to bring it "to the house" to
test it.

There....that's better....(c;

--
Larry
 >> Stay informed about: Laptop trips GFI 

Excellent point!

"Larry" wrote in message

> "johnhh" wrote in
> iA.TakeThisOut@comcast.com:
>
>> I need to remember to bring the thing home
>
> Oh, oh....needs attitude adjustment....
>
> The laptop IS already home. You just need to bring it "to the house" to
> test it.
>
> There....that's better....(c;
>
> --
> Larry
 >> Stay informed about: Laptop trips GFI 

A ground buster would be one way to check for excessive leakage to
ground. But exercise caution: the GFI is tripping either because it is
defective or because there is a potentially dangerous leakage. We tend
to immediately suspect a more or less constant borderline leakage such
as might occur in the case of a defective or poorly designed filter as
Larry suggests. Or it could be a less-likely but very serious
intermittent condition like a short. If so, with a ground buster in the
circuit, your body could well supply the leakage path to ground.

But most of the chargers use 2-wire, "polarized" ac cords in which case
the ground buster would have no effect. With a 2-wire cord and a
properly functioning GFI and nothing else plugged into the receptacle or
the computer, a trip can occur only if you provide the path to ground.
If it trips while you are not touching it and it is fully insulated from
the boat's ac ground, the GFI is probably defective.

You still haven't told us if your GFI is a breaker type in the main
panel or a receptacle. If the latter, why not just plug the computer
into one of the other protected outlets on the boat? If the former,
complex grounding or wiring situations could cause the problem.

Good luck.

Chuck

Larry wrote:
> If it has 3-wire grounded plug on it, plug it into a ground buster and see
> if it stops. The input filters on some of the switching supplies allows
> enough AC to ground pin to trip them. I've had some ground loops trip mine
> here at home from certain printers plugged into the outlets on other
> circuits than what the computer is plugged into.
>
> "johnhh" wrote in
>
>
>
>>All of my 110 outlets on the boat are protected through GFI. Whenever
>>I plug my laptop charger in or turn on the computer with it plugged
>>in, it trips the GFI. If I reset it a time or two or three, it will
>>hold and work fine until the next time. Interestingly, it will even
>>trip the GFI on a parallel circuit. I am guessing that it has
>>something to do with the large capacitor in the charging unit charging
>>up. Does anyone have an explanation and/or solution?
>>
>>thanks
>>john
>>
>>
>>
>
>
>
>
 >> Stay informed about: Laptop trips GFI 

--It is a GFI receptacle, not a breaker.
--The charger (110AC to 18.5v DC) has a 3 wire plug.
--It only occurs with the laptop and always occurs with the laptop
--It makes no difference what else is connected to the laptop or AC.
--It occurs whenever the computer is turned on or the charger is plugged
into an already running computer.
--It always recovers after one to three resets.
--It is far too consistent to be an intermittent condition like a short.
--It usually, but not always, trips both the GFI it is plugged into and the
other one on a parallel circuit.
--I have two different AC circuits off of the same breaker but each
protected by a GFI outlet. I am not sure of the exact wiring of these as I
haven't traced the wires down.

--No matter how much information I think I give or imply, I always seem to
leave something out.

--I'll try it on the second GFI on the boat, but will be very surprised if
it works there.
--I'll bring it to the house at the next opportunity and try it there.
--I'll try a ground buster.

I am of the belief that there is really nothing wrong with anything.
Larry's induced current theory sounds reasonable. These chargers have a
very large capacitance that take a second or so to charge up. I believe it
has to do with that charging somehow.



"chuck" wrote in message

>A ground buster would be one way to check for excessive leakage to ground.
>But exercise caution: the GFI is tripping either because it is defective or
>because there is a potentially dangerous leakage. We tend to immediately
>suspect a more or less constant borderline leakage such as might occur in
>the case of a defective or poorly designed filter as Larry suggests. Or it
>could be a less-likely but very serious intermittent condition like a
>short. If so, with a ground buster in the circuit, your body could well
>supply the leakage path to ground.
>
> But most of the chargers use 2-wire, "polarized" ac cords in which case
> the ground buster would have no effect. With a 2-wire cord and a properly
> functioning GFI and nothing else plugged into the receptacle or the
> computer, a trip can occur only if you provide the path to ground. If it
> trips while you are not touching it and it is fully insulated from the
> boat's ac ground, the GFI is probably defective.
>
> You still haven't told us if your GFI is a breaker type in the main panel
> or a receptacle. If the latter, why not just plug the computer into one of
> the other protected outlets on the boat? If the former, complex grounding
> or wiring situations could cause the problem.
>
> Good luck.
>
> Chuck
>
> Larry wrote:
>> If it has 3-wire grounded plug on it, plug it into a ground buster and
>> see if it stops. The input filters on some of the switching supplies
>> allows enough AC to ground pin to trip them. I've had some ground loops
>> trip mine here at home from certain printers plugged into the outlets on
>> other circuits than what the computer is plugged into.
>>
>> "johnhh" wrote in
>>
>>>All of my 110 outlets on the boat are protected through GFI. Whenever
>>>I plug my laptop charger in or turn on the computer with it plugged
>>>in, it trips the GFI. If I reset it a time or two or three, it will
>>>hold and work fine until the next time. Interestingly, it will even
>>>trip the GFI on a parallel circuit. I am guessing that it has
>>>something to do with the large capacitor in the charging unit charging
>>>up. Does anyone have an explanation and/or solution?
>>>
>>>thanks
>>>john
>>>
>>>
>>
>>
>>
 >> Stay informed about: Laptop trips GFI 

"johnhh" wrote in


> I am of the belief that there is really nothing wrong with anything.
> Larry's induced current theory sounds reasonable. These chargers have
> a very large capacitance that take a second or so to charge up. I
> believe it has to do with that charging somehow.
>
>

I'm also leaning, because it trips a GFI it's not connected to, that the
switcher is sending lots of RF noise back up the power line. Take a small
portable AM radio and put it near the power supply. Tune up and down the
band and listen for "hash" when the supply is plugged in. The hash fed
back into the GFI may also be what's tripping it...and the other one.
Terrible designs do make it to market from China.

--
Larry
 >> Stay informed about: Laptop trips GFI 

johnhh wrote:

> All of my 110 outlets on the boat are protected through GFI. Whenever I plug
> my laptop charger in or turn on the computer with it plugged in, it trips
> the GFI. If I reset it a time or two or three, it will hold and work fine
> until the next time. Interestingly, it will even trip the GFI on a parallel
> circuit. I am guessing that it has something to do with the large capacitor
> in the charging unit charging up. Does anyone have an explanation and/or
> solution?
>
> thanks
> john
>
>

All gfi protected circuit branches the same? If so, a laptop fault,
potentially dangerous should be investigated by a professional. Is
your laptop connected to external speakers, or other accessories,
possibly interconnected with equipment on a different phase of mains
power?

Most laptops use only 2 wire plugs, so cannot have a current
imbalance in the cableset typically the cause of gfi tripping. You
may have a bad gfi. You may have a salty moist sweat stain on plug
terminal, wire, grip, etc, to some earthed part of the boat. Clean
the plug end with a mild detergent and dry thoroughly.

If yours has a 3 wire plug, it may have a marginal leakage path from
a hot terminal to the safety ground. This can be difficult to
prove, as the current is so small, and it trips so fast.

You could test with a 2 wire extension cord, to see if this stops
the tripping. It might not be safe to use it regularly without
repairing the cause. You might be best to use insulating gloves
while doing this test.

It seems unlikely there is an electrical contact on the case of the
laptop that might be in contact with an earth or even your hand, but
that too would only indicate an internal leakage through the power
supply or charger, which could be lethal, if circumstances get right.

As to why it might cause tripping a gfi in some other part of the
power system, you got me there, buddy, unless one gfi is feeding the
other, and they are just taking turns at tripping;-)

I think startup current surges would not affect a gfic, first
because as far as I know, they are not designed to be overcurrent
circuit breakers, except insofar as safety imbalance current is
concerned and second, no laptop should draw so large a surge. If so,
I would suspect a resistive or reactive neutral or hot connection
path. Do you have galvanic diode blockers in your shoreside earth
line connector path? Do you have a wireless card in your laptop?

Are you, as did a friend of mine, amazingly still alive, using a 110
v device in series with a 220 v flourescent ballast circuit?
Stranger things exist in truth than in fiction.

Very curious.

Terry K
 >> Stay informed about: Laptop trips GFI 

Reflects my sentiments also, Terry.

Depending on the nature of any leakage, it may show up with a simple
ohmmeter test. If the resistance between the ground prong on the plug
and either of the other terminals is anywhere in the vicinity of 20,000
ohms (6 mA @ 120 v) that is the problem. Ideally, your ohmmeter should
indicate an open circuit. These devices use disk ceramic capacitors that
frequently develop troublesome leakage resistance.

Chuck

Terry Spragg wrote:
> johnhh wrote:
>

>
> All gfi protected circuit branches the same? If so, a laptop fault,
> potentially dangerous should be investigated by a professional. Is your
> laptop connected to external speakers, or other accessories, possibly
> interconnected with equipment on a different phase of mains power?
>
> Most laptops use only 2 wire plugs, so cannot have a current imbalance
> in the cableset typically the cause of gfi tripping. You may have a bad
> gfi. You may have a salty moist sweat stain on plug terminal, wire,
> grip, etc, to some earthed part of the boat. Clean the plug end with a
> mild detergent and dry thoroughly.
>
> If yours has a 3 wire plug, it may have a marginal leakage path from a
> hot terminal to the safety ground. This can be difficult to prove, as
> the current is so small, and it trips so fast.
>
> You could test with a 2 wire extension cord, to see if this stops the
> tripping. It might not be safe to use it regularly without repairing
> the cause. You might be best to use insulating gloves while doing this
> test.
>
> It seems unlikely there is an electrical contact on the case of the
> laptop that might be in contact with an earth or even your hand, but
> that too would only indicate an internal leakage through the power
> supply or charger, which could be lethal, if circumstances get right.
>
> As to why it might cause tripping a gfi in some other part of the power
> system, you got me there, buddy, unless one gfi is feeding the other,
> and they are just taking turns at tripping;-)
>
> I think startup current surges would not affect a gfic, first because as
> far as I know, they are not designed to be overcurrent circuit breakers,
> except insofar as safety imbalance current is concerned and second, no
> laptop should draw so large a surge. If so, I would suspect a resistive
> or reactive neutral or hot connection path. Do you have galvanic diode
> blockers in your shoreside earth line connector path? Do you have a
> wireless card in your laptop?
>
> Are you, as did a friend of mine, amazingly still alive, using a 110 v
> device in series with a 220 v flourescent ballast circuit? Stranger
> things exist in truth than in fiction.
>
> Very curious.
>
> Terry K
>
 >> Stay informed about: Laptop trips GFI 

I'll run the resistance test when I get back to the boat, but I don't see
that it is going to tell me anything since the leakage only occurs when a
load is first applied to the DC side of the power brick. Even at that, it
takes more than just applying a load since there is a load charging the
batteries even if the laptop is not turned on. I haven't been back to the
boat since I started this thread, but will get more info the next time I go
up.

thanks for all of your feedback.

John

"chuck" wrote in message

> Reflects my sentiments also, Terry.
>
> Depending on the nature of any leakage, it may show up with a simple
> ohmmeter test. If the resistance between the ground prong on the plug and
> either of the other terminals is anywhere in the vicinity of 20,000 ohms
> (6 mA @ 120 v) that is the problem. Ideally, your ohmmeter should indicate
> an open circuit. These devices use disk ceramic capacitors that frequently
> develop troublesome leakage resistance.
>
> Chuck
>
> Terry Spragg wrote:
>> johnhh wrote:
>>
>
>>
>> All gfi protected circuit branches the same? If so, a laptop fault,
>> potentially dangerous should be investigated by a professional. Is your
>> laptop connected to external speakers, or other accessories, possibly
>> interconnected with equipment on a different phase of mains power?
>>
>> Most laptops use only 2 wire plugs, so cannot have a current imbalance in
>> the cableset typically the cause of gfi tripping. You may have a bad gfi.
>> You may have a salty moist sweat stain on plug terminal, wire, grip, etc,
>> to some earthed part of the boat. Clean the plug end with a mild
>> detergent and dry thoroughly.
>>
>> If yours has a 3 wire plug, it may have a marginal leakage path from a
>> hot terminal to the safety ground. This can be difficult to prove, as
>> the current is so small, and it trips so fast.
>>
>> You could test with a 2 wire extension cord, to see if this stops the
>> tripping. It might not be safe to use it regularly without repairing the
>> cause. You might be best to use insulating gloves while doing this test.
>>
>> It seems unlikely there is an electrical contact on the case of the
>> laptop that might be in contact with an earth or even your hand, but that
>> too would only indicate an internal leakage through the power supply or
>> charger, which could be lethal, if circumstances get right.
>>
>> As to why it might cause tripping a gfi in some other part of the power
>> system, you got me there, buddy, unless one gfi is feeding the other, and
>> they are just taking turns at tripping;-)
>>
>> I think startup current surges would not affect a gfic, first because as
>> far as I know, they are not designed to be overcurrent circuit breakers,
>> except insofar as safety imbalance current is concerned and second, no
>> laptop should draw so large a surge. If so, I would suspect a resistive
>> or reactive neutral or hot connection path. Do you have galvanic diode
>> blockers in your shoreside earth line connector path? Do you have a
>> wireless card in your laptop?
>>
>> Are you, as did a friend of mine, amazingly still alive, using a 110 v
>> device in series with a 220 v flourescent ballast circuit? Stranger
>> things exist in truth than in fiction.
>>
>> Very curious.
>>
>> Terry K
>>
 >> Stay informed about: Laptop trips GFI 

All appliances have leakage. Leakage that should be so low
as to not add up to a problem. It is doubtful that laptop is
leaking milliamps on startup. IOW there would be something
else on the circuit leaking so much that just a little laptop
leakage could trip the GFCI.

Unlikely that you will find leakage with the ohm meter.
Try. But eliminating other items from the circuit, then
powering on the laptop will probably provide better
information.

Informative may be a current measurement of that circuit's
ground wire. How much current (in AC milliamps and DC
milliamps) is flowing down that ground wire for various
powered on appliances on that circuit?

johnhh wrote:
> I'll run the resistance test when I get back to the boat, but I
> don't see that it is going to tell me anything since the leakage
> only occurs when a load is first applied to the DC side of the
> power brick. Even at that, it takes more than just applying a
> load since there is a load charging the batteries even if the
> laptop is not turned on. I haven't been back to the boat since
> I started this thread, but will get more info the next time I
> go up.
 >> Stay informed about: Laptop trips GFI 

It is especially troublesome that the GFCI trips only when the laptop is
plugged into the power supply. There is supposed to be substantial
electrical isolation between the so-called "hot" and "cold" grounds
(i.e., between the AC and DC grounds). Unless that isolation (usually an
opto-isolator) is compromised, I can't imagine a mechanism by which the
laptop itself could trip a GFCI, even if it were hanging overboard and
immersed in seawater while connected! Not so for the power supply, of
course.

Larry's theory of a monster-sized common-mode switching noise signal
propagating through the AC lines to trip both GFCI outlets is looking
more attractive. At least that theory supports a mechanism by which
plugging in the laptop causes a GFCI trip: going from no-load to
full-load would cause a change in switching characteristics that might
produce more noise on the line.

20,000 ohms or less of leakage can easily be measured on a DMM and
leaking RF filter capacitors are common. It would be a good idea to
measure leakage with and without the laptop connected to the power supply.

Chuck

w_tom wrote:
> All appliances have leakage. Leakage that should be so low
> as to not add up to a problem. It is doubtful that laptop is
> leaking milliamps on startup. IOW there would be something
> else on the circuit leaking so much that just a little laptop
> leakage could trip the GFCI.
>
> Unlikely that you will find leakage with the ohm meter.
> Try. But eliminating other items from the circuit, then
> powering on the laptop will probably provide better
> information.
>
> Informative may be a current measurement of that circuit's
> ground wire. How much current (in AC milliamps and DC
> milliamps) is flowing down that ground wire for various
> powered on appliances on that circuit?
>
 >> Stay informed about: Laptop trips GFI