GFCI 's

[big joe]

Hi everybody! Big Joe here!, I have a Newbie question for you all,regarding GFCI's. Now I was wondering what the normal way everybody does this. First off I'am in WI. and we have snow. I bought the 16 ch. starter pc version, I'am making my own cords(spt-2), I'am going to be running all full-wave l.e.d's. I have the power supply to the controller plugged into two seperate GFCI circuits. My question is : should I now have seperate GFCI's plugged in after the spt-2 run before the actual "string"? and if so what should I use? My common sense, tells me yes- that way if there is a problem with the "string" it would be a faster way to diognose at the "string" then to check the whole system. ugh!! Any idea's would be appreciated. Yes I know my spelling isn't the greatest, Thankyou.

[George Simmons]

I think one of the most overlooked issues with GFCI's is their potential for benefitting all the rest of us. Most widows of people who DIDN'T use GFCIs probably don't know the real value of late hubby's controllers. When they clean out all the Christmas junk they'll likely give those controllers away for a song just to get them out of their sight.

[big joe]

thanks Jeff. That was a great idea and I will follow your advice. I was once hit with what was described to me later by the electricain on the job as "static-line stray voltage", on a job at a papermill. I was working out of a sizzor-lift and near a 440 volt line. Didn't really relise what had happend right away, but knew right away that both of my arms hurt. After I came down I could remember both of my arms jerking back and forth really fast. I went and got the sparky and sent his ass up there and he said what he said. I went to work somewhere else on the job after that.

[dgrant]

I've been nailed by 440 once as well. Certainly wasn't any fun and in this case, not my fault rather an electrical failure. GFCI's work by detecting an abnormal flow of power from the hot side but not the same on the neutral side. It looks for this and if the two don't match in flow rates, then it quickly trips off the power. Water dripping into the power connections outside can cause a path between the hot and neutral wires therefore tripping the GFCI. If anyone has come up with a good way of stopping this, I'd sure love to hear it.

[Dr. Jones]

dgrant wrote:

Water dripping into the power connections outside can cause a path between the hot and neutral wires therefore tripping the GFCI. If anyone has come up with a good way of stopping this, I'd sure love to hear it.

ip68 rated electrical connectors!

[Surfing4Dough]

dgrant wrote:

I've been nailed by 440 once as well. Certainly wasn't any fun and in this case, not my fault rather an electrical failure. GFCI's work by detecting an abnormal flow of power from the hot side but not the same on the neutral side. It looks for this and if the two don't match in flow rates, then it quickly trips off the power. Water dripping into the power connections outside can cause a path between the hot and neutral wires therefore tripping the GFCI. If anyone has come up with a good way of stopping this, I'd sure love to hear it.

But typically "clean" rainwater alone doesn't conduct well enough to allow this to happen. It usually requires "dirtier" water, such as that that is sitting on the ground (has had a chance to mix with dirt or chemicals such as fertilizer). Water off the ground seeping into the connection causes a problem. That is why keeping connections off the ground works so well. Likewise, the connection should be clean to begin with--make sure dry dirt/debris/mulch doesn't get on the connecting parts to begin with since it will later get wet.

[Dr. Jones]

Jeff Millard wrote:

I hope this helps, and I hope you choose to use GFCI. Electrical safety is paramount in this hobby. You'll find there are people who shun the use of safety devices. I won't. (I've ignored them on this forum...):cool:

Jeff

Have you seen or used a Bender Lifegaurd? - For non residential applications, they are phenominal

[dgrant]

Surfing4Dough wrote:

dgrant wrote:

I've been nailed by 440 once as well. Certainly wasn't any fun and in this case, not my fault rather an electrical failure. GFCI's work by detecting an abnormal flow of power from the hot side but not the same on the neutral side. It looks for this and if the two don't match in flow rates, then it quickly trips off the power. Water dripping into the power connections outside can cause a path between the hot and neutral wires therefore tripping the GFCI. If anyone has come up with a good way of stopping this, I'd sure love to hear it.

But typically "clean" rainwater alone doesn't conduct well enough to allow this to happen.  It usually requires "dirtier" water, such as that that is sitting on the ground (has had a chance to mix with dirt or chemicals such as fertilizer). Water off the ground seeping into the connection causes a problem. That is why keeping connections off the ground works so well.  Likewise, the connection should be clean to begin with--make sure dry dirt/debris/mulch doesn't get on the connecting parts to begin with since it will later get wet. 

Pure water is not a conductor of electricity however any impurities or minerals in water, will conduct. Yes, ground water from whatever will conduct which is our issues of course. Pure rain water might not conduct unless you live in S. Calif where it rains mud...lol. I was contemplating sealing the connections with silcone after insuring they are clean and dry to start with. Getting them off the ground is a given.

[james campbell]

since we are on the subject,I had trouble from My mini tree last year. i was thinking of using wrap around pipe insulation to get the metal frames off the ground,will this work?

[dgrant]

james campbell wrote:

since we are on the subject,I had trouble from My mini tree last year. i was thinking of using wrap around pipe insulation to get the metal frames off the ground,will this work?

Unless you've got a wire shorted to the frame itself, it shouldn't matter but if you do have a short, then it needs to be resolved otherwise you are endangering your life.

[Dr. Jones]

dgrant wrote:

Surfing4Dough wrote:

dgrant wrote:

I've been nailed by 440 once as well. Certainly wasn't any fun and in this case, not my fault rather an electrical failure. GFCI's work by detecting an abnormal flow of power from the hot side but not the same on the neutral side. It looks for this and if the two don't match in flow rates, then it quickly trips off the power. Water dripping into the power connections outside can cause a path between the hot and neutral wires therefore tripping the GFCI. If anyone has come up with a good way of stopping this, I'd sure love to hear it.

But typically "clean" rainwater alone doesn't conduct well enough to allow this to happen. It usually requires "dirtier" water, such as that that is sitting on the ground (has had a chance to mix with dirt or chemicals such as fertilizer). Water off the ground seeping into the connection causes a problem. That is why keeping connections off the ground works so well. Likewise, the connection should be clean to begin with--make sure dry dirt/debris/mulch doesn't get on the connecting parts to begin with since it will later get wet.

Pure water is not a conductor of electricity however any impurities or minerals in water, will conduct. Yes, ground water from whatever will conduct which is our issues of course. Pure rain water might not conduct unless you live in S. Calif where it rains mud...lol. I was contemplating sealing the connections with silcone after insuring they are clean and dry to start with. Getting them off the ground is a given.

for a less permanent solution you may try dielectric grease

and- rain water contains impurities from the atmosphere, even comercially available distilled water can potentially conduct electricity

[Dr. Jones]

james campbell wrote:

since we are on the subject,I had trouble from My mini tree last year. i was thinking of using wrap around pipe insulation to get the metal frames off the ground,will this work?

I have seen mentioned before of people using liquid electrical tape or even wood blocks to insulate the frames

[james campbell]

dgrant wrote:

james campbell wrote:

since we are on the subject,I had trouble from My mini tree last year. i was thinking of using wrap around pipe insulation to get the metal frames off the ground,will this work?

Unless you've got a wire shorted to the frame itself, it shouldn't matter but if you do have a short, then it needs to be resolved otherwise you are endangering your life.

don't think it's a short only trips during rain( if the ground is saturated) after it stops raining I can reset about 30 minutes after and it runs fine

[Max-Paul]

dgrant wrote:

I've been nailed by 440 once as well. Certainly wasn't any fun and in this case, not my fault rather an electrical failure. GFCI's work by detecting an abnormal flow of power from the hot side but not the same on the neutral side. It looks for this and if the two don't match in flow rates, then it quickly trips off the power. Water dripping into the power connections outside can cause a path between the hot and neutral wires therefore tripping the GFCI. If anyone has come up with a good way of stopping this, I'd sure love to hear it.

I'm sorry but the above statement about current flowing between hot and neutral wires is normal and a GFCI will NOT trip. It is when there is current flow between hot and ground.

I was going to snip the first part of your post. But funny thing is that in the first half you state the correct information about how a GFCI works. Then the second half you get it all wrong.

[Max-Paul]

dgrant wrote:

james campbell wrote:

since we are on the subject,I had trouble from My mini tree last year. i was thinking of using wrap around pipe insulation to get the metal frames off the ground,will this work?

Unless you've got a wire shorted to the frame itself, it shouldn't matter but if you do have a short, then it needs to be resolved otherwise you are endangering your life.

dgrant,
Your knowledge of GFCI and Christmas lights is found lacking. It is well known among those of us who have been here for awhile and sharing that there is a thing called capacitive coupling. Do you understand how a capassitor works? If not, maybe some reading is in order to fully understand what I am tell you. Light strings laying on the ground or on metal frames that are sitting on the ground. Can add up the "leakage" of current to the ground. Thus causing an imbalance inside of the GFCI.

[Max-Paul]

James,

I cant see how you are going to do this with the wrap around pipe insulation. But others have used wooden stakes (not so good) or short pieces of small PVC pipes driven into the ground and then a small hole drilled near the top, big enough for a tye wrap to go through and then the tomato cage. this is to elevate the mini tree a few inches above the ground / snow.

More items that come in contact with the ground, the more items will need to be shifted onto different GFCIs to minimize the amount of leakage per GFCI.

[dgrant]

Max-Paul wrote:

dgrant wrote:

james campbell wrote:

since we are on the subject,I had trouble from My mini tree last year. i was thinking of using wrap around pipe insulation to get the metal frames off the ground,will this work?

Unless you've got a wire shorted to the frame itself, it shouldn't matter but if you do have a short, then it needs to be resolved otherwise you are endangering your life.

dgrant,
Your knowledge of GFCI and Christmas lights is found lacking. It is well known among those of us who have been here for awhile and sharing that there is a thing called capacitive coupling. Do you understand how a capassitor works? If not, maybe some reading is in order to fully understand what I am tell you. Light strings laying on the ground or on metal frames that are sitting on the ground. Can add up the "leakage" of current to the ground. Thus causing an imbalance inside of the GFCI.

I'm no expert on GFCI as I had to do a quick search online to tell me how it works. That was the first answer that I found. I too have had issues with the GFCI popping on my static displays every time it rained too. So I'm trying to prevent that as well. Now ask me about spacecraft testing, software programming, computers and a ton of other things, then I'm the guy. For years, I too thought that the GFCI monitored across the hot to ground but the article I read today online said it was the hot to neutral...I assumed I was just wrong all this time but truly, I did not know the fact.

[DSE]

Just curious how did capacitive coupling come into the terminology of Ground fault interruption circuit?

Was under the impression any leakage from L1,L2 or ground would trip the circuit

[Max-Paul]

DSE,

First you got to understand how a GFCI works. I see you call out L1, L2, and ground, but you forgot an important ingredient, the Neutral leg.

Ok, lesson time. First a simple single hot lead, or L1 type. Current flowing out L1 or hot, has to the same current flowing back in through the Neutral lead. Ok there is usually a 5mA error tolerance. So, if the current is not coming back in via the Neutral leg, it has to be coming back via ground.

Now on a GFCI that has two hot leads or a dual breaker. Gets a bit more complicated but this will also hold true for a 3 phase breaker. First I got to say this, any current on the neutral leg will be checked for phasing and that current value will be applied to the proper hot lead current total. So current between L1 & L2 with any current on the neutral lead must balance, again with the 5mA tolerance.

Now DSE do you know what a capacitor is? And what does it do? I am trying to figure you out. Do you really not understand or are you dont want to do some reading?

[PipefitterDan]

Max-Paul, for a little clarification when you say "coming back via ground" do you mean through the ground wire or by any means to the ground. Such as through my hand, up my arm, down my side and out my foot. Some people could be confused by your comment.