GFCI= "Go F'in Click It (again)!

[lowepg]

100% chance of rain foretasted today.... ugh.

 

I experimented with spraying half my minitrees bases with plastic-dip to see if it will help with the incessant gfci trips in the rain...

 

[atver]

Hope you post your experiment findings.

[habmann]

I feel your pain, rain in to problems with the GFCI on my house yesterday. Seems the thawing ice everywhere was causing the problems. Back to normal today thankfully.

[lowepg]

Experiment = fail.

 

:-(

[atver]

Oh well, it was a nice try on your part.  This is the way we learn.

[a31ford]

As dumb as this sounds.....

 

drive a short ground rod into the soil, where your  never mind, I don't want to get sued for someone popping a gas line....

 

Ground (earth) the FAR ends of your 3rd prong POWER (NOT lights) cables (At the endpoint of the cable that feed the controllers ), this will stop the spastic trips BUT will still trip if you accidentally touch hot.

 

The GFI's need to know where "Earth" (WE CALL IT GROUND) is, running systems like this, with many cables branching out of a controller, over senses the GFI's 3rd pin reference, if you ground it there (at the far end), it sets the potential difference (called skew voltage) to 0.

 

The GFI's still work as intended, and will still trip in extremes or really bad weather, but for the most part, will fix the garbage tripping.  

 

NOTE:

NO, I will not be held responsible, use this information AT YOUR OWN RISK,

It is VERY wise to RESEARCH  this issue at length BEFORE you undertake any modifications.

 

Greg

[a31ford]

I know many of you will say, Christmas lights do not use a 3rd pin, (I know that).

 

The issue is called "Floating Bias"

 

There IS a coupling effect in long cable runs, with no point of reference to ground, the 3rd wire will build a small bias voltage that causes the GFI to "spastic trip", because of it.

 

Merry Christmas

THINK of it as a "snubber" for GFI's NO there is NOT a resistor.

[KStatefan]

How does this work? All the GFCI does is compare the current on the ungrounded  conductor (hot) and the grounded conductor (neutral) and there is a difference it trips. 

[a31ford]

We tend to group our power cables. do an internet search for "stray voltages" this should answer more than I have.

 

Skew, Bias, Stray, they are all effects of many cables near each other.

 

Greg

http://en.wikipedia.org/wiki/Stray_voltage

[a31ford]

look at Induced voltages also.

[plasmadrive]

As dumb as this sounds.....

 

drive a short ground rod into the soil, where your  never mind, I don't want to get sued for someone popping a gas line....

 

Ground (earth) the FAR ends of your 3rd prong POWER (NOT lights) cables (At the endpoint of the cable that feed the controllers ), this will stop the spastic trips BUT will still trip if you accidentally touch hot.

 

The GFI's need to know where "Earth" (WE CALL IT GROUND) is, running systems like this, with many cables branching out of a controller, over senses the GFI's 3rd pin reference, if you ground it there (at the far end), it sets the potential difference (called skew voltage) to 0.

 

The GFI's still work as intended, and will still trip in extremes or really bad weather, but for the most part, will fix the garbage tripping.  

 

NOTE:

NO, I will not be held responsible, use this information AT YOUR OWN RISK,

It is VERY wise to RESEARCH  this issue at length BEFORE you undertake any modifications.

 

Greg

Where did you come up with this? 

[a31ford]

Plasma...

 

 

 FWIW, I'm an Electronics Tech, been one for the better part of 40 years (Not that it really matters, just setting the stage for my information).

 

Stray, Induced, Bias, and Skew are all voltages that can happen in electrical.

 

Here's a good source of "what" and for the most part, I agree (from my own knowledge) with what is there.

 

http://en.wikipedia.org/wiki/Stray_voltage

 

I'm going to PM you if you don't mind

 

Greg

[-klb-]

Draining stray voltages may help, but not by affecting how the GFCI senses ground. The GFCI doesn't use ground. In fact in some cases, a GFCI is the only legal 3 pin outlet that can be installed without a ground wire available.

Reducing stray voltages will reduce leakage in/out of the neutral wire by reducing the voltage to neutral, and thus the current that flows if a leak to neutral exists. That can reduce trips right there. But also, if the stray voltage is from one side of the service, grounding it out will reduce the total voltage to hot from the other leg, again reducing total leakage current.

But most of the show I run is in a stray voltage field like most users won't experience. It is in the easement of a 135KV and 350KV overhead power line. Non contact voltage probes can't be used because they go off anywhere in this park.

Between using nearly all sealed LED strings, moving to one GFCI per controller, no extension cords on the grounded inlet cords, keeping connections up off the ground, and occasionally shielding them from falling rain (as a side benefit to how they were kept off the ground) we have reduced GFCI trips in that park to zero, and have not had any on the firehouse this year. And we are up to four separate utility feeds powering the show. So we don't even have a consistent ground.

[a31ford]

Uh, OK, if you say so,

 

But in my neck of the woods, you can trip a GFI  by touching  the White side of the outlet (Tall blade), to the ground  (Round pin). 

 

I'll also add that the Canadian Electrical Code requires ALL outlets to be grounded, period (Absolutely NO exceptions).

 

Remember, things are NOT the same this side of the 49th.

 

 

Heck we even have a better screwdriver (Robertson), Beats the *&^p out a Phillips ANY DAY.

 

Greg

[-klb-]

Of course you can trip a GFCI by connecting neutral to ground. You are allowing an alternate path to conduct and the hot and neutral current at the GFCI no longer match. You can trip them by touching unrelated neutrals together as long as at least 6mA flows through the connection. Same with two unrelated hot leads on the same phase.