False GFCI tripping

Sorry, that's "sine" wave.

in article WNk7d.109251$ snipped-for-privacy@twister.nyroc.rr.com, Dave M. at snipped-for-privacy@rochester.rr.com wrote on 10/1/04 3:23 PM:

Consider capacitive ground fault current either due to filtering or from stray capacitance.

Bill

| Since inductive loads (especially high power loads) on occasion, cause false | GFCI tripping. It would seem to me, that in basic terms, this is the result | of induced current from a coil I.E. motor stator coil to it's grounded | laminations, and which causes an asymmetrical current or current spike from | the hot or neutral side to ground and a result of coincidences, such as the | moment the power switch is turned and the phase of the power sign wave.

I've been able to cause false tripping of GFCIs even with no load on the circuit at all.

As your sigunature has an Amateur Radio calsign I suspect due to RFI intrusion form operating your radio station into the GFCI.

Gary K8IZ

GFIs were invented for those who use a hair dryer in the shower. If you're smarter than that, remove the GRI. My friend replaced his with a normal outlet and is still alive.

Al

On Sat, 02 Oct 2004 21:01:30 GMT Gary P. Fiber wrote: | | On 2 Oct 2004 07:12:05 GMT, snipped-for-privacy@ipal.net wrote: | |>On Fri, 01 Oct 2004 22:23:50 GMT Dave M. wrote: |>

|>| Since inductive loads (especially high power loads) on occasion, cause false |>| GFCI tripping. It would seem to me, that in basic terms, this is the result |>| of induced current from a coil I.E. motor stator coil to it's grounded |>| laminations, and which causes an asymmetrical current or current spike from |>| the hot or neutral side to ground and a result of coincidences, such as the |>| moment the power switch is turned and the phase of the power sign wave. |>

|>I've been able to cause false tripping of GFCIs even with no load on the |>circuit at all. | | As your sigunature has an Amateur Radio calsign I suspect due to | RFI intrusion form operating your radio station into the GFCI. | | Gary K8IZ

Very good insight. 2 meters did it.

On Sun, 03 Oct 2004 15:09:18 GMT Al wrote: | In article , | Gary P. Fiber wrote: | |> On 2 Oct 2004 07:12:05 GMT, snipped-for-privacy@ipal.net wrote: |> |> >On Fri, 01 Oct 2004 22:23:50 GMT Dave M. wrote: |> >

|> >| Since inductive loads (especially high power loads) on occasion, cause |> >| false |> >| GFCI tripping. It would seem to me, that in basic terms, this is the |> >| result |> >| of induced current from a coil I.E. motor stator coil to it's grounded |> >| laminations, and which causes an asymmetrical current or current spike |> >| from |> >| the hot or neutral side to ground and a result of coincidences, such as |> >| the |> >| moment the power switch is turned and the phase of the power sign wave. |> >

|> >I've been able to cause false tripping of GFCIs even with no load on the |> >circuit at all. |> |> As your sigunature has an Amateur Radio calsign I suspect due to |> RFI intrusion form operating your radio station into the GFCI. |> |> Gary K8IZ | | GFIs were invented for those who use a hair dryer in the shower. If | you're smarter than that, remove the GRI. My friend replaced his with a | normal outlet and is still alive.

I prefer having the protection just in case. What I don't like are the ones where current imbalance (which can be fooled by common mode RF induced onto the line) can activate the tripping mechanism EVEN AFTER THE CIRCUIT IS OPEN. In other words, as long as the RF is present and the voltage is present on the line side of the GFCI receptacle, the tripping mechanism was working. My big worry is that because these solenoids are NOT designed for continuous duty operation, they can be fire hazards if they overheat during such activation, by melting down and letting line voltage short out.

And of course RFI filters would help. It would be nice of someone has figured out just what would work safely to block RFI from the line to the device.