How much mains leakage does an Ethernet connection to a PC induce, and what is the operating leakage...

"the same as" in a sentence

Using "tail" to follow a file without displaying the most recent lines

Can I hook these wires up to find the connection to a dead outlet?

How could indestructible materials be used in power generation?

Is it a bad idea to plug the other end of ESD strap to wall ground?

Getting extremely large arrows with tikzcd

Am I breaking OOP practice with this architecture?

Car headlights in a world without electricity

What is required to make GPS signals available indoors?

Does the Idaho Potato Commission associate potato skins with healthy eating?

Is it possible to map the firing of neurons in the human brain so as to stimulate artificial memories in someone else?

Is this draw by repetition?

How to install cross-compiler on Ubuntu 18.04?

Finding the error in an argument

Could the museum Saturn V's be refitted for one more flight?

Does int main() need a declaration on C++?

Why was Sir Cadogan fired?

Avoiding the "not like other girls" trope?

My ex-girlfriend uses my Apple ID to log in to her iPad. Do I have to give her my Apple ID password to reset it?

Do creatures with a listed speed of "0 ft., fly 30 ft. (hover)" ever touch the ground?

In Bayesian inference, why are some terms dropped from the posterior predictive?

Why didn't Boeing produce its own regional jet?

How to prevent "they're falling in love" trope

Does Dispel Magic work on Tiny Hut?



How much mains leakage does an Ethernet connection to a PC induce, and what is the operating leakage path?


Does an ATX power supply have any isolated outputs?What does the Arduino ethernet shield connect to?Ethernet phy connection: grounding between chassis, connector and IONon-isolated mains circuit and EthernetAdding a resistive path between live conductors and earth - safety issuesDoes the 802.3 Ethernet standard provide a recommended circuit design?Isolation transformer and AC potential between groundsHow to stop leakage of mains adaptorWhat is GMAC/EMAC and does it define a physical connection to an ethernet chip?How does Ethernet magnetics work?What are the NAND Trees that Ethernet datasheets refer to?













4












$begingroup$


It seems that some users on another Stack have reported GFCI nuisance trips caused by mains leakage through twisted-pair Ethernet cables connected between computers on different branch circuits, or more specifically, between a computer with a Class I, chassis-mounted, supply conforming to IEC 60950 connected to a grounded receptacle with UL 943 Class A GFCI protection, and a switch that is a Class III appliance with a Class II power supply, connected to a grounded, but unprotected, receptacle on a different branch circuit.



While, conceptually speaking, the idea that there could be a leakage path through the data cable makes some sense, and I have seen Ethernet reference circuits that have termination RC networks from the port-side center-tap terminals in the magnetics to chassis ground as well as a 1nF capacitor between chassis and signal grounds, it seems to me that it would be very poor engineering for this leakage path to allow the mains leakage current to rise to a magnitude exceeding the IEC 60950 standards.



What is the magnitude of this Ethernet-connection-induced leakage current rise, what factors in the design of the equipment involved control this rise, and can someone describe to me the precise leakage loop involved?










share|improve this question









$endgroup$








  • 1




    $begingroup$
    I think the user on DIY is full of it. if the power supply in the PC is isolated, there shouldn't be any leakage that will trip a GFCI. Maybe he routes his ethernet cables by coiling them around the power cables?
    $endgroup$
    – The Photon
    3 hours ago






  • 1




    $begingroup$
    @ThePhoton -- unfortunately, I'm not in a situation to test it (don't have the network setup or the sensitive leakage clampmeter needed for that) or else I would put this theory to the test! If anyone wishes to experiment with this, though, I'd love to hear about it!
    $endgroup$
    – ThreePhaseEel
    3 hours ago












  • $begingroup$
    I've got a router, computer and laser printer networked together on a GFCI receptacle. Networked back to FIOS box and to another computer both not on this GFCI, and the GFCI hasn't tripped ever (~ 13 years). On the other hand, all the GFCI stuff is also going through a UPS (laser is on the surge-protection-only part) so that may mask any potential problem, though until ~ 6 years ago it wasn't on a UPS. But (as noted in DIY), I've never seen this problem anywhere and I have quite a few customers - I would think I'd come across the problem occasionally if was at all common.
    $endgroup$
    – manassehkatz
    2 hours ago








  • 2




    $begingroup$
    One caveat to my above comment: It's entirely possible (in fact, it's certain) there are some shitty power supplies out there being used in PCs.
    $endgroup$
    – The Photon
    2 hours ago










  • $begingroup$
    Related: Does an ATX power supply have any isolated outputs?.
    $endgroup$
    – The Photon
    2 hours ago
















4












$begingroup$


It seems that some users on another Stack have reported GFCI nuisance trips caused by mains leakage through twisted-pair Ethernet cables connected between computers on different branch circuits, or more specifically, between a computer with a Class I, chassis-mounted, supply conforming to IEC 60950 connected to a grounded receptacle with UL 943 Class A GFCI protection, and a switch that is a Class III appliance with a Class II power supply, connected to a grounded, but unprotected, receptacle on a different branch circuit.



While, conceptually speaking, the idea that there could be a leakage path through the data cable makes some sense, and I have seen Ethernet reference circuits that have termination RC networks from the port-side center-tap terminals in the magnetics to chassis ground as well as a 1nF capacitor between chassis and signal grounds, it seems to me that it would be very poor engineering for this leakage path to allow the mains leakage current to rise to a magnitude exceeding the IEC 60950 standards.



What is the magnitude of this Ethernet-connection-induced leakage current rise, what factors in the design of the equipment involved control this rise, and can someone describe to me the precise leakage loop involved?










share|improve this question









$endgroup$








  • 1




    $begingroup$
    I think the user on DIY is full of it. if the power supply in the PC is isolated, there shouldn't be any leakage that will trip a GFCI. Maybe he routes his ethernet cables by coiling them around the power cables?
    $endgroup$
    – The Photon
    3 hours ago






  • 1




    $begingroup$
    @ThePhoton -- unfortunately, I'm not in a situation to test it (don't have the network setup or the sensitive leakage clampmeter needed for that) or else I would put this theory to the test! If anyone wishes to experiment with this, though, I'd love to hear about it!
    $endgroup$
    – ThreePhaseEel
    3 hours ago












  • $begingroup$
    I've got a router, computer and laser printer networked together on a GFCI receptacle. Networked back to FIOS box and to another computer both not on this GFCI, and the GFCI hasn't tripped ever (~ 13 years). On the other hand, all the GFCI stuff is also going through a UPS (laser is on the surge-protection-only part) so that may mask any potential problem, though until ~ 6 years ago it wasn't on a UPS. But (as noted in DIY), I've never seen this problem anywhere and I have quite a few customers - I would think I'd come across the problem occasionally if was at all common.
    $endgroup$
    – manassehkatz
    2 hours ago








  • 2




    $begingroup$
    One caveat to my above comment: It's entirely possible (in fact, it's certain) there are some shitty power supplies out there being used in PCs.
    $endgroup$
    – The Photon
    2 hours ago










  • $begingroup$
    Related: Does an ATX power supply have any isolated outputs?.
    $endgroup$
    – The Photon
    2 hours ago














4












4








4





$begingroup$


It seems that some users on another Stack have reported GFCI nuisance trips caused by mains leakage through twisted-pair Ethernet cables connected between computers on different branch circuits, or more specifically, between a computer with a Class I, chassis-mounted, supply conforming to IEC 60950 connected to a grounded receptacle with UL 943 Class A GFCI protection, and a switch that is a Class III appliance with a Class II power supply, connected to a grounded, but unprotected, receptacle on a different branch circuit.



While, conceptually speaking, the idea that there could be a leakage path through the data cable makes some sense, and I have seen Ethernet reference circuits that have termination RC networks from the port-side center-tap terminals in the magnetics to chassis ground as well as a 1nF capacitor between chassis and signal grounds, it seems to me that it would be very poor engineering for this leakage path to allow the mains leakage current to rise to a magnitude exceeding the IEC 60950 standards.



What is the magnitude of this Ethernet-connection-induced leakage current rise, what factors in the design of the equipment involved control this rise, and can someone describe to me the precise leakage loop involved?










share|improve this question









$endgroup$




It seems that some users on another Stack have reported GFCI nuisance trips caused by mains leakage through twisted-pair Ethernet cables connected between computers on different branch circuits, or more specifically, between a computer with a Class I, chassis-mounted, supply conforming to IEC 60950 connected to a grounded receptacle with UL 943 Class A GFCI protection, and a switch that is a Class III appliance with a Class II power supply, connected to a grounded, but unprotected, receptacle on a different branch circuit.



While, conceptually speaking, the idea that there could be a leakage path through the data cable makes some sense, and I have seen Ethernet reference circuits that have termination RC networks from the port-side center-tap terminals in the magnetics to chassis ground as well as a 1nF capacitor between chassis and signal grounds, it seems to me that it would be very poor engineering for this leakage path to allow the mains leakage current to rise to a magnitude exceeding the IEC 60950 standards.



What is the magnitude of this Ethernet-connection-induced leakage current rise, what factors in the design of the equipment involved control this rise, and can someone describe to me the precise leakage loop involved?







ethernet leakage-current






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked 3 hours ago









ThreePhaseEelThreePhaseEel

6,69641534




6,69641534








  • 1




    $begingroup$
    I think the user on DIY is full of it. if the power supply in the PC is isolated, there shouldn't be any leakage that will trip a GFCI. Maybe he routes his ethernet cables by coiling them around the power cables?
    $endgroup$
    – The Photon
    3 hours ago






  • 1




    $begingroup$
    @ThePhoton -- unfortunately, I'm not in a situation to test it (don't have the network setup or the sensitive leakage clampmeter needed for that) or else I would put this theory to the test! If anyone wishes to experiment with this, though, I'd love to hear about it!
    $endgroup$
    – ThreePhaseEel
    3 hours ago












  • $begingroup$
    I've got a router, computer and laser printer networked together on a GFCI receptacle. Networked back to FIOS box and to another computer both not on this GFCI, and the GFCI hasn't tripped ever (~ 13 years). On the other hand, all the GFCI stuff is also going through a UPS (laser is on the surge-protection-only part) so that may mask any potential problem, though until ~ 6 years ago it wasn't on a UPS. But (as noted in DIY), I've never seen this problem anywhere and I have quite a few customers - I would think I'd come across the problem occasionally if was at all common.
    $endgroup$
    – manassehkatz
    2 hours ago








  • 2




    $begingroup$
    One caveat to my above comment: It's entirely possible (in fact, it's certain) there are some shitty power supplies out there being used in PCs.
    $endgroup$
    – The Photon
    2 hours ago










  • $begingroup$
    Related: Does an ATX power supply have any isolated outputs?.
    $endgroup$
    – The Photon
    2 hours ago














  • 1




    $begingroup$
    I think the user on DIY is full of it. if the power supply in the PC is isolated, there shouldn't be any leakage that will trip a GFCI. Maybe he routes his ethernet cables by coiling them around the power cables?
    $endgroup$
    – The Photon
    3 hours ago






  • 1




    $begingroup$
    @ThePhoton -- unfortunately, I'm not in a situation to test it (don't have the network setup or the sensitive leakage clampmeter needed for that) or else I would put this theory to the test! If anyone wishes to experiment with this, though, I'd love to hear about it!
    $endgroup$
    – ThreePhaseEel
    3 hours ago












  • $begingroup$
    I've got a router, computer and laser printer networked together on a GFCI receptacle. Networked back to FIOS box and to another computer both not on this GFCI, and the GFCI hasn't tripped ever (~ 13 years). On the other hand, all the GFCI stuff is also going through a UPS (laser is on the surge-protection-only part) so that may mask any potential problem, though until ~ 6 years ago it wasn't on a UPS. But (as noted in DIY), I've never seen this problem anywhere and I have quite a few customers - I would think I'd come across the problem occasionally if was at all common.
    $endgroup$
    – manassehkatz
    2 hours ago








  • 2




    $begingroup$
    One caveat to my above comment: It's entirely possible (in fact, it's certain) there are some shitty power supplies out there being used in PCs.
    $endgroup$
    – The Photon
    2 hours ago










  • $begingroup$
    Related: Does an ATX power supply have any isolated outputs?.
    $endgroup$
    – The Photon
    2 hours ago








1




1




$begingroup$
I think the user on DIY is full of it. if the power supply in the PC is isolated, there shouldn't be any leakage that will trip a GFCI. Maybe he routes his ethernet cables by coiling them around the power cables?
$endgroup$
– The Photon
3 hours ago




$begingroup$
I think the user on DIY is full of it. if the power supply in the PC is isolated, there shouldn't be any leakage that will trip a GFCI. Maybe he routes his ethernet cables by coiling them around the power cables?
$endgroup$
– The Photon
3 hours ago




1




1




$begingroup$
@ThePhoton -- unfortunately, I'm not in a situation to test it (don't have the network setup or the sensitive leakage clampmeter needed for that) or else I would put this theory to the test! If anyone wishes to experiment with this, though, I'd love to hear about it!
$endgroup$
– ThreePhaseEel
3 hours ago






$begingroup$
@ThePhoton -- unfortunately, I'm not in a situation to test it (don't have the network setup or the sensitive leakage clampmeter needed for that) or else I would put this theory to the test! If anyone wishes to experiment with this, though, I'd love to hear about it!
$endgroup$
– ThreePhaseEel
3 hours ago














$begingroup$
I've got a router, computer and laser printer networked together on a GFCI receptacle. Networked back to FIOS box and to another computer both not on this GFCI, and the GFCI hasn't tripped ever (~ 13 years). On the other hand, all the GFCI stuff is also going through a UPS (laser is on the surge-protection-only part) so that may mask any potential problem, though until ~ 6 years ago it wasn't on a UPS. But (as noted in DIY), I've never seen this problem anywhere and I have quite a few customers - I would think I'd come across the problem occasionally if was at all common.
$endgroup$
– manassehkatz
2 hours ago






$begingroup$
I've got a router, computer and laser printer networked together on a GFCI receptacle. Networked back to FIOS box and to another computer both not on this GFCI, and the GFCI hasn't tripped ever (~ 13 years). On the other hand, all the GFCI stuff is also going through a UPS (laser is on the surge-protection-only part) so that may mask any potential problem, though until ~ 6 years ago it wasn't on a UPS. But (as noted in DIY), I've never seen this problem anywhere and I have quite a few customers - I would think I'd come across the problem occasionally if was at all common.
$endgroup$
– manassehkatz
2 hours ago






2




2




$begingroup$
One caveat to my above comment: It's entirely possible (in fact, it's certain) there are some shitty power supplies out there being used in PCs.
$endgroup$
– The Photon
2 hours ago




$begingroup$
One caveat to my above comment: It's entirely possible (in fact, it's certain) there are some shitty power supplies out there being used in PCs.
$endgroup$
– The Photon
2 hours ago












$begingroup$
Related: Does an ATX power supply have any isolated outputs?.
$endgroup$
– The Photon
2 hours ago




$begingroup$
Related: Does an ATX power supply have any isolated outputs?.
$endgroup$
– The Photon
2 hours ago










3 Answers
3






active

oldest

votes


















1












$begingroup$

The ethernet connection leakage current should be negligable, with UTP.
Every port has a array of transformers for high frequency, the leakage at 50 Hz common mode will be very low.
enter image description here



However, if shielded cable is used, S-UTP or CAT7 cables, there will also be made a chassis connection between the two devices.

Then the power supply leakage enters the equation, and those may leak several milliamperes.



*(image source)






share|improve this answer









$endgroup$













  • $begingroup$
    Yep, shielded cable was my concern too.
    $endgroup$
    – Ale..chenski
    11 mins ago



















0












$begingroup$



So I'm the user on DIY.



I had some original experience at work where we coudn't get the new portable generator to power more than one computer even though the old one did. We eventually bisected it to the GFCI outlet in the new generator.



Later on, I had to track down why my AFCI breaker kept tripping. The electrician I called tested the AFCI breaker by bridging a resistor between power and ground. That tripped it. He said that AFCI breakers work by detecting ground faults. I originally said he was nuts, but it turns out it was true.



I got a copy of a circuit for RJ45 magnetics. The critical point is RXN and TXN are tied together by a pair of identical resistors R6 and R7 and capacitor C15 which is 10nF ties that bridge line to ground. In steady state, C15 would indeed conduct no current; however when sending a packet, the impedance of C15 1 / jωC = 1 / j(2·10⁹)(10·10⁻⁹) = 1/j20. This gives the resulting current flow of I = V/R = 3.3/2/49.9² + 1/20²)¹ᐟ² = .033 amps.



And that's just that one capacitor. I haven't been able to locate the indicator LEDs yet. I've noticed that the connection indicator LED on quite a few computers will light even when the board is unpowered but not when unplugged. Conclusion: that LED is tied between the Ethernet cable on one side and the ground on the other, and that ground is often the neutral wire rather than the house ground (two wire devices ...).



Now the electrician was in fact telling the truth. Old series AFCI breakers would trip at something like .1 amps of ground loop by specification. The gigabit switch I was using at the time was a two wire device (no dedicated ground) so all of that current had to go into the neutral wire. New AFCI breakers have since been fixed to work by other means than ground fault detection and replacing the AFCI breaker was the solution.



GFCI outlets are documented to trip at .004 amps. Guess what happens when you run Ethernet cables between devices on different circuits where one of them doesn't have a ground wire. And I'm pretty sure from the bisection that most of these cheaper power supplies were tying the motherboard ground to the neutral wire not the ground wire despite the ground wire being available.






share|improve this answer











$endgroup$













  • $begingroup$
    So HIGH SLEW RATE Ethernet signals are, lacking OTHER return paths, using the PowerLine as RETURN?
    $endgroup$
    – analogsystemsrf
    2 hours ago










  • $begingroup$
    @analogsystemsrf: Yup! Was expecting it as soon as I learned how carrier sense worked. Come to think of it, that's probably why that line is tied to neutral rather than ground in the PCs. If it were tied to ground it would have a hard time returning to a two-wire device.
    $endgroup$
    – Joshua
    2 hours ago










  • $begingroup$
    When you say "that ground is often the neutral wire", if that's true then your PC vendor hasn't provided a properly isolated power supply and is violating safety regulations in any first-world country.
    $endgroup$
    – The Photon
    2 hours ago










  • $begingroup$
    The ground on this schematic would be the negative power rail for the entire circuit. Every part of the computer will send current to the same ground that's on this schematic. In electronics, ground usually just means zero volts, not "real ground".
    $endgroup$
    – immibis
    2 hours ago












  • $begingroup$
    (Even if it was real ground, you didn't account for the fact that RXN and RXP should change with opposite polarity to each other, so the voltage on the capacitor shouldn't change)
    $endgroup$
    – immibis
    2 hours ago



















0












$begingroup$

Tripping a GFCI usually occurs when there is a missmatch between the current going in and the current going out. While there could exist mutual inductance between cables, I don't think it would generate enough current because properly designed Ethernet ports have mega ohms of impedance at DC. I'll find some impedance graphs for the Chokes tomorrow, but if I remember right there is high attention for lower frequencies through chokes, and highly unlikely to pass much current 60Hz through DC.



If the cable was improperly built there could be a pathway there






share|improve this answer









$endgroup$














    Your Answer





    StackExchange.ifUsing("editor", function () {
    return StackExchange.using("mathjaxEditing", function () {
    StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
    StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
    });
    });
    }, "mathjax-editing");

    StackExchange.ifUsing("editor", function () {
    return StackExchange.using("schematics", function () {
    StackExchange.schematics.init();
    });
    }, "cicuitlab");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "135"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: false,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: null,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f430425%2fhow-much-mains-leakage-does-an-ethernet-connection-to-a-pc-induce-and-what-is-t%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    3 Answers
    3






    active

    oldest

    votes








    3 Answers
    3






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    1












    $begingroup$

    The ethernet connection leakage current should be negligable, with UTP.
    Every port has a array of transformers for high frequency, the leakage at 50 Hz common mode will be very low.
    enter image description here



    However, if shielded cable is used, S-UTP or CAT7 cables, there will also be made a chassis connection between the two devices.

    Then the power supply leakage enters the equation, and those may leak several milliamperes.



    *(image source)






    share|improve this answer









    $endgroup$













    • $begingroup$
      Yep, shielded cable was my concern too.
      $endgroup$
      – Ale..chenski
      11 mins ago
















    1












    $begingroup$

    The ethernet connection leakage current should be negligable, with UTP.
    Every port has a array of transformers for high frequency, the leakage at 50 Hz common mode will be very low.
    enter image description here



    However, if shielded cable is used, S-UTP or CAT7 cables, there will also be made a chassis connection between the two devices.

    Then the power supply leakage enters the equation, and those may leak several milliamperes.



    *(image source)






    share|improve this answer









    $endgroup$













    • $begingroup$
      Yep, shielded cable was my concern too.
      $endgroup$
      – Ale..chenski
      11 mins ago














    1












    1








    1





    $begingroup$

    The ethernet connection leakage current should be negligable, with UTP.
    Every port has a array of transformers for high frequency, the leakage at 50 Hz common mode will be very low.
    enter image description here



    However, if shielded cable is used, S-UTP or CAT7 cables, there will also be made a chassis connection between the two devices.

    Then the power supply leakage enters the equation, and those may leak several milliamperes.



    *(image source)






    share|improve this answer









    $endgroup$



    The ethernet connection leakage current should be negligable, with UTP.
    Every port has a array of transformers for high frequency, the leakage at 50 Hz common mode will be very low.
    enter image description here



    However, if shielded cable is used, S-UTP or CAT7 cables, there will also be made a chassis connection between the two devices.

    Then the power supply leakage enters the equation, and those may leak several milliamperes.



    *(image source)







    share|improve this answer












    share|improve this answer



    share|improve this answer










    answered 15 mins ago









    Jeroen3Jeroen3

    11.6k1748




    11.6k1748












    • $begingroup$
      Yep, shielded cable was my concern too.
      $endgroup$
      – Ale..chenski
      11 mins ago


















    • $begingroup$
      Yep, shielded cable was my concern too.
      $endgroup$
      – Ale..chenski
      11 mins ago
















    $begingroup$
    Yep, shielded cable was my concern too.
    $endgroup$
    – Ale..chenski
    11 mins ago




    $begingroup$
    Yep, shielded cable was my concern too.
    $endgroup$
    – Ale..chenski
    11 mins ago













    0












    $begingroup$



    So I'm the user on DIY.



    I had some original experience at work where we coudn't get the new portable generator to power more than one computer even though the old one did. We eventually bisected it to the GFCI outlet in the new generator.



    Later on, I had to track down why my AFCI breaker kept tripping. The electrician I called tested the AFCI breaker by bridging a resistor between power and ground. That tripped it. He said that AFCI breakers work by detecting ground faults. I originally said he was nuts, but it turns out it was true.



    I got a copy of a circuit for RJ45 magnetics. The critical point is RXN and TXN are tied together by a pair of identical resistors R6 and R7 and capacitor C15 which is 10nF ties that bridge line to ground. In steady state, C15 would indeed conduct no current; however when sending a packet, the impedance of C15 1 / jωC = 1 / j(2·10⁹)(10·10⁻⁹) = 1/j20. This gives the resulting current flow of I = V/R = 3.3/2/49.9² + 1/20²)¹ᐟ² = .033 amps.



    And that's just that one capacitor. I haven't been able to locate the indicator LEDs yet. I've noticed that the connection indicator LED on quite a few computers will light even when the board is unpowered but not when unplugged. Conclusion: that LED is tied between the Ethernet cable on one side and the ground on the other, and that ground is often the neutral wire rather than the house ground (two wire devices ...).



    Now the electrician was in fact telling the truth. Old series AFCI breakers would trip at something like .1 amps of ground loop by specification. The gigabit switch I was using at the time was a two wire device (no dedicated ground) so all of that current had to go into the neutral wire. New AFCI breakers have since been fixed to work by other means than ground fault detection and replacing the AFCI breaker was the solution.



    GFCI outlets are documented to trip at .004 amps. Guess what happens when you run Ethernet cables between devices on different circuits where one of them doesn't have a ground wire. And I'm pretty sure from the bisection that most of these cheaper power supplies were tying the motherboard ground to the neutral wire not the ground wire despite the ground wire being available.






    share|improve this answer











    $endgroup$













    • $begingroup$
      So HIGH SLEW RATE Ethernet signals are, lacking OTHER return paths, using the PowerLine as RETURN?
      $endgroup$
      – analogsystemsrf
      2 hours ago










    • $begingroup$
      @analogsystemsrf: Yup! Was expecting it as soon as I learned how carrier sense worked. Come to think of it, that's probably why that line is tied to neutral rather than ground in the PCs. If it were tied to ground it would have a hard time returning to a two-wire device.
      $endgroup$
      – Joshua
      2 hours ago










    • $begingroup$
      When you say "that ground is often the neutral wire", if that's true then your PC vendor hasn't provided a properly isolated power supply and is violating safety regulations in any first-world country.
      $endgroup$
      – The Photon
      2 hours ago










    • $begingroup$
      The ground on this schematic would be the negative power rail for the entire circuit. Every part of the computer will send current to the same ground that's on this schematic. In electronics, ground usually just means zero volts, not "real ground".
      $endgroup$
      – immibis
      2 hours ago












    • $begingroup$
      (Even if it was real ground, you didn't account for the fact that RXN and RXP should change with opposite polarity to each other, so the voltage on the capacitor shouldn't change)
      $endgroup$
      – immibis
      2 hours ago
















    0












    $begingroup$



    So I'm the user on DIY.



    I had some original experience at work where we coudn't get the new portable generator to power more than one computer even though the old one did. We eventually bisected it to the GFCI outlet in the new generator.



    Later on, I had to track down why my AFCI breaker kept tripping. The electrician I called tested the AFCI breaker by bridging a resistor between power and ground. That tripped it. He said that AFCI breakers work by detecting ground faults. I originally said he was nuts, but it turns out it was true.



    I got a copy of a circuit for RJ45 magnetics. The critical point is RXN and TXN are tied together by a pair of identical resistors R6 and R7 and capacitor C15 which is 10nF ties that bridge line to ground. In steady state, C15 would indeed conduct no current; however when sending a packet, the impedance of C15 1 / jωC = 1 / j(2·10⁹)(10·10⁻⁹) = 1/j20. This gives the resulting current flow of I = V/R = 3.3/2/49.9² + 1/20²)¹ᐟ² = .033 amps.



    And that's just that one capacitor. I haven't been able to locate the indicator LEDs yet. I've noticed that the connection indicator LED on quite a few computers will light even when the board is unpowered but not when unplugged. Conclusion: that LED is tied between the Ethernet cable on one side and the ground on the other, and that ground is often the neutral wire rather than the house ground (two wire devices ...).



    Now the electrician was in fact telling the truth. Old series AFCI breakers would trip at something like .1 amps of ground loop by specification. The gigabit switch I was using at the time was a two wire device (no dedicated ground) so all of that current had to go into the neutral wire. New AFCI breakers have since been fixed to work by other means than ground fault detection and replacing the AFCI breaker was the solution.



    GFCI outlets are documented to trip at .004 amps. Guess what happens when you run Ethernet cables between devices on different circuits where one of them doesn't have a ground wire. And I'm pretty sure from the bisection that most of these cheaper power supplies were tying the motherboard ground to the neutral wire not the ground wire despite the ground wire being available.






    share|improve this answer











    $endgroup$













    • $begingroup$
      So HIGH SLEW RATE Ethernet signals are, lacking OTHER return paths, using the PowerLine as RETURN?
      $endgroup$
      – analogsystemsrf
      2 hours ago










    • $begingroup$
      @analogsystemsrf: Yup! Was expecting it as soon as I learned how carrier sense worked. Come to think of it, that's probably why that line is tied to neutral rather than ground in the PCs. If it were tied to ground it would have a hard time returning to a two-wire device.
      $endgroup$
      – Joshua
      2 hours ago










    • $begingroup$
      When you say "that ground is often the neutral wire", if that's true then your PC vendor hasn't provided a properly isolated power supply and is violating safety regulations in any first-world country.
      $endgroup$
      – The Photon
      2 hours ago










    • $begingroup$
      The ground on this schematic would be the negative power rail for the entire circuit. Every part of the computer will send current to the same ground that's on this schematic. In electronics, ground usually just means zero volts, not "real ground".
      $endgroup$
      – immibis
      2 hours ago












    • $begingroup$
      (Even if it was real ground, you didn't account for the fact that RXN and RXP should change with opposite polarity to each other, so the voltage on the capacitor shouldn't change)
      $endgroup$
      – immibis
      2 hours ago














    0












    0








    0





    $begingroup$



    So I'm the user on DIY.



    I had some original experience at work where we coudn't get the new portable generator to power more than one computer even though the old one did. We eventually bisected it to the GFCI outlet in the new generator.



    Later on, I had to track down why my AFCI breaker kept tripping. The electrician I called tested the AFCI breaker by bridging a resistor between power and ground. That tripped it. He said that AFCI breakers work by detecting ground faults. I originally said he was nuts, but it turns out it was true.



    I got a copy of a circuit for RJ45 magnetics. The critical point is RXN and TXN are tied together by a pair of identical resistors R6 and R7 and capacitor C15 which is 10nF ties that bridge line to ground. In steady state, C15 would indeed conduct no current; however when sending a packet, the impedance of C15 1 / jωC = 1 / j(2·10⁹)(10·10⁻⁹) = 1/j20. This gives the resulting current flow of I = V/R = 3.3/2/49.9² + 1/20²)¹ᐟ² = .033 amps.



    And that's just that one capacitor. I haven't been able to locate the indicator LEDs yet. I've noticed that the connection indicator LED on quite a few computers will light even when the board is unpowered but not when unplugged. Conclusion: that LED is tied between the Ethernet cable on one side and the ground on the other, and that ground is often the neutral wire rather than the house ground (two wire devices ...).



    Now the electrician was in fact telling the truth. Old series AFCI breakers would trip at something like .1 amps of ground loop by specification. The gigabit switch I was using at the time was a two wire device (no dedicated ground) so all of that current had to go into the neutral wire. New AFCI breakers have since been fixed to work by other means than ground fault detection and replacing the AFCI breaker was the solution.



    GFCI outlets are documented to trip at .004 amps. Guess what happens when you run Ethernet cables between devices on different circuits where one of them doesn't have a ground wire. And I'm pretty sure from the bisection that most of these cheaper power supplies were tying the motherboard ground to the neutral wire not the ground wire despite the ground wire being available.






    share|improve this answer











    $endgroup$





    So I'm the user on DIY.



    I had some original experience at work where we coudn't get the new portable generator to power more than one computer even though the old one did. We eventually bisected it to the GFCI outlet in the new generator.



    Later on, I had to track down why my AFCI breaker kept tripping. The electrician I called tested the AFCI breaker by bridging a resistor between power and ground. That tripped it. He said that AFCI breakers work by detecting ground faults. I originally said he was nuts, but it turns out it was true.



    I got a copy of a circuit for RJ45 magnetics. The critical point is RXN and TXN are tied together by a pair of identical resistors R6 and R7 and capacitor C15 which is 10nF ties that bridge line to ground. In steady state, C15 would indeed conduct no current; however when sending a packet, the impedance of C15 1 / jωC = 1 / j(2·10⁹)(10·10⁻⁹) = 1/j20. This gives the resulting current flow of I = V/R = 3.3/2/49.9² + 1/20²)¹ᐟ² = .033 amps.



    And that's just that one capacitor. I haven't been able to locate the indicator LEDs yet. I've noticed that the connection indicator LED on quite a few computers will light even when the board is unpowered but not when unplugged. Conclusion: that LED is tied between the Ethernet cable on one side and the ground on the other, and that ground is often the neutral wire rather than the house ground (two wire devices ...).



    Now the electrician was in fact telling the truth. Old series AFCI breakers would trip at something like .1 amps of ground loop by specification. The gigabit switch I was using at the time was a two wire device (no dedicated ground) so all of that current had to go into the neutral wire. New AFCI breakers have since been fixed to work by other means than ground fault detection and replacing the AFCI breaker was the solution.



    GFCI outlets are documented to trip at .004 amps. Guess what happens when you run Ethernet cables between devices on different circuits where one of them doesn't have a ground wire. And I'm pretty sure from the bisection that most of these cheaper power supplies were tying the motherboard ground to the neutral wire not the ground wire despite the ground wire being available.







    share|improve this answer














    share|improve this answer



    share|improve this answer








    edited 2 hours ago

























    answered 2 hours ago









    JoshuaJoshua

    21515




    21515












    • $begingroup$
      So HIGH SLEW RATE Ethernet signals are, lacking OTHER return paths, using the PowerLine as RETURN?
      $endgroup$
      – analogsystemsrf
      2 hours ago










    • $begingroup$
      @analogsystemsrf: Yup! Was expecting it as soon as I learned how carrier sense worked. Come to think of it, that's probably why that line is tied to neutral rather than ground in the PCs. If it were tied to ground it would have a hard time returning to a two-wire device.
      $endgroup$
      – Joshua
      2 hours ago










    • $begingroup$
      When you say "that ground is often the neutral wire", if that's true then your PC vendor hasn't provided a properly isolated power supply and is violating safety regulations in any first-world country.
      $endgroup$
      – The Photon
      2 hours ago










    • $begingroup$
      The ground on this schematic would be the negative power rail for the entire circuit. Every part of the computer will send current to the same ground that's on this schematic. In electronics, ground usually just means zero volts, not "real ground".
      $endgroup$
      – immibis
      2 hours ago












    • $begingroup$
      (Even if it was real ground, you didn't account for the fact that RXN and RXP should change with opposite polarity to each other, so the voltage on the capacitor shouldn't change)
      $endgroup$
      – immibis
      2 hours ago


















    • $begingroup$
      So HIGH SLEW RATE Ethernet signals are, lacking OTHER return paths, using the PowerLine as RETURN?
      $endgroup$
      – analogsystemsrf
      2 hours ago










    • $begingroup$
      @analogsystemsrf: Yup! Was expecting it as soon as I learned how carrier sense worked. Come to think of it, that's probably why that line is tied to neutral rather than ground in the PCs. If it were tied to ground it would have a hard time returning to a two-wire device.
      $endgroup$
      – Joshua
      2 hours ago










    • $begingroup$
      When you say "that ground is often the neutral wire", if that's true then your PC vendor hasn't provided a properly isolated power supply and is violating safety regulations in any first-world country.
      $endgroup$
      – The Photon
      2 hours ago










    • $begingroup$
      The ground on this schematic would be the negative power rail for the entire circuit. Every part of the computer will send current to the same ground that's on this schematic. In electronics, ground usually just means zero volts, not "real ground".
      $endgroup$
      – immibis
      2 hours ago












    • $begingroup$
      (Even if it was real ground, you didn't account for the fact that RXN and RXP should change with opposite polarity to each other, so the voltage on the capacitor shouldn't change)
      $endgroup$
      – immibis
      2 hours ago
















    $begingroup$
    So HIGH SLEW RATE Ethernet signals are, lacking OTHER return paths, using the PowerLine as RETURN?
    $endgroup$
    – analogsystemsrf
    2 hours ago




    $begingroup$
    So HIGH SLEW RATE Ethernet signals are, lacking OTHER return paths, using the PowerLine as RETURN?
    $endgroup$
    – analogsystemsrf
    2 hours ago












    $begingroup$
    @analogsystemsrf: Yup! Was expecting it as soon as I learned how carrier sense worked. Come to think of it, that's probably why that line is tied to neutral rather than ground in the PCs. If it were tied to ground it would have a hard time returning to a two-wire device.
    $endgroup$
    – Joshua
    2 hours ago




    $begingroup$
    @analogsystemsrf: Yup! Was expecting it as soon as I learned how carrier sense worked. Come to think of it, that's probably why that line is tied to neutral rather than ground in the PCs. If it were tied to ground it would have a hard time returning to a two-wire device.
    $endgroup$
    – Joshua
    2 hours ago












    $begingroup$
    When you say "that ground is often the neutral wire", if that's true then your PC vendor hasn't provided a properly isolated power supply and is violating safety regulations in any first-world country.
    $endgroup$
    – The Photon
    2 hours ago




    $begingroup$
    When you say "that ground is often the neutral wire", if that's true then your PC vendor hasn't provided a properly isolated power supply and is violating safety regulations in any first-world country.
    $endgroup$
    – The Photon
    2 hours ago












    $begingroup$
    The ground on this schematic would be the negative power rail for the entire circuit. Every part of the computer will send current to the same ground that's on this schematic. In electronics, ground usually just means zero volts, not "real ground".
    $endgroup$
    – immibis
    2 hours ago






    $begingroup$
    The ground on this schematic would be the negative power rail for the entire circuit. Every part of the computer will send current to the same ground that's on this schematic. In electronics, ground usually just means zero volts, not "real ground".
    $endgroup$
    – immibis
    2 hours ago














    $begingroup$
    (Even if it was real ground, you didn't account for the fact that RXN and RXP should change with opposite polarity to each other, so the voltage on the capacitor shouldn't change)
    $endgroup$
    – immibis
    2 hours ago




    $begingroup$
    (Even if it was real ground, you didn't account for the fact that RXN and RXP should change with opposite polarity to each other, so the voltage on the capacitor shouldn't change)
    $endgroup$
    – immibis
    2 hours ago











    0












    $begingroup$

    Tripping a GFCI usually occurs when there is a missmatch between the current going in and the current going out. While there could exist mutual inductance between cables, I don't think it would generate enough current because properly designed Ethernet ports have mega ohms of impedance at DC. I'll find some impedance graphs for the Chokes tomorrow, but if I remember right there is high attention for lower frequencies through chokes, and highly unlikely to pass much current 60Hz through DC.



    If the cable was improperly built there could be a pathway there






    share|improve this answer









    $endgroup$


















      0












      $begingroup$

      Tripping a GFCI usually occurs when there is a missmatch between the current going in and the current going out. While there could exist mutual inductance between cables, I don't think it would generate enough current because properly designed Ethernet ports have mega ohms of impedance at DC. I'll find some impedance graphs for the Chokes tomorrow, but if I remember right there is high attention for lower frequencies through chokes, and highly unlikely to pass much current 60Hz through DC.



      If the cable was improperly built there could be a pathway there






      share|improve this answer









      $endgroup$
















        0












        0








        0





        $begingroup$

        Tripping a GFCI usually occurs when there is a missmatch between the current going in and the current going out. While there could exist mutual inductance between cables, I don't think it would generate enough current because properly designed Ethernet ports have mega ohms of impedance at DC. I'll find some impedance graphs for the Chokes tomorrow, but if I remember right there is high attention for lower frequencies through chokes, and highly unlikely to pass much current 60Hz through DC.



        If the cable was improperly built there could be a pathway there






        share|improve this answer









        $endgroup$



        Tripping a GFCI usually occurs when there is a missmatch between the current going in and the current going out. While there could exist mutual inductance between cables, I don't think it would generate enough current because properly designed Ethernet ports have mega ohms of impedance at DC. I'll find some impedance graphs for the Chokes tomorrow, but if I remember right there is high attention for lower frequencies through chokes, and highly unlikely to pass much current 60Hz through DC.



        If the cable was improperly built there could be a pathway there







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered 20 mins ago









        laptop2dlaptop2d

        27.1k123584




        27.1k123584






























            draft saved

            draft discarded




















































            Thanks for contributing an answer to Electrical Engineering Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            Use MathJax to format equations. MathJax reference.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f430425%2fhow-much-mains-leakage-does-an-ethernet-connection-to-a-pc-induce-and-what-is-t%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            Why do type traits not work with types in namespace scope?What are POD types in C++?Why can templates only be...

            Will tsunami waves travel forever if there was no land?Why do tsunami waves begin with the water flowing away...

            Simple Scan not detecting my scanner (Brother DCP-7055W)Brother MFC-L2700DW printer can print, can't...