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eswets
12-29-2008, 01:15 AM
Now this is not a question about the safety aspect of the GFCI, but a question on if the controllers or SSR need the GFCI protection. Lots of rain and lots of GFCI are tripping. I am an electrician and I know the "importance" of them for outdoors, but does the SSR or controller benefit from having the protection. As soon as a moved one of the feeds from the gfci to a non protected outlet I never had a issue since and am thinking of removing all gfci that are dedicated to the lights. Again I don't need to know the safety reasons for keeping them.

NogginBoink
12-29-2008, 01:50 AM
There's nothing in particular about the SSR that requires GFCI protection.

Macrosill
12-29-2008, 09:47 AM
Well if you remove the ssrs from GFCI protected branch circuits then the lights and display items being controlled by the ssrs no longer have any GFCI protection. I am sure you know this eswets but I just wanted to point it out to anyone who may read this and not realize the fact.

I am a very big GFCI advocate, I will never do without GFCI protection on my display, I would rather turn it off than have someone get hurt. I will also always strongly recommend everyone use GFCIs on every circuit utilized outdoors or in indoor areas that have contact with the ground, as in a garage with a cement slab.

Jeff Millard
12-29-2008, 12:09 PM
...but does the SSR or controller benefit from having the protection.

GFCI isn't meant to benefit a particular device. It is meant to detect undesirable leakage away from the preferred path that current flows, and disconnect the feed of that circuit if that leakage reaches a value that is about 1/10th what is considered to be fatal. It is purely a safety device, meant to prevent death by electrocution.

Sooo....


...I don't need to know the safety reasons for keeping them.

Maybe you do. Let's just for a second compare the difference between a .05 Amp shock (which can, and will interrupt a heartbeat) and an 18 amp (I have tested this value on 10 separate 15 amp breakers, so I am confident with 18 amps as the trip value) electrocution. Removing the GFCI means that the amount of current required to make a 15 amp circuit breaker trip is 360 times what is considered to be fatal. While a GFCI will detect an improper current flow of .005 amps and trip. The first will stop the heart. The second will burn flesh. Really fast, and really graphically.

The only thing really important about a GFCI is the safety it provides to those who could possibly touch live circuits. Using it on the items in a display is the responsible thing to do. Those who have problems with circuits tripping have a responsibility to the public that views their display, to troubleshoot and eliminate the things that are causing the nuisance trips. There is a long line of people who use GFCI without the trips, so it can be done. There are discussions on each and every forum related to this hobby describing what was done to fix problems. If you have to leave the yard grid out of your display because it trips the GFCI... Oh well. Better that than have to call an ambulance or the ME because little Jimmy's Mom couldn't hold onto him right when a big twinkle sequence hit the entire diplay... so he just had to run through the lights...

I cringe every time I hear someone say I took the GFCI out and I don't have the problem now. I've seen the result of safety devices bypassed throughout my occupation in a public electric utility. It's ugly, and it stinks. If the question is: "Does the GFCI provide any benefit to a particular device?" The answer is quite simply, no, it doesn't. The fuse in the SSR is a protective device for the SSR. But that doesn't preclude the need for a rant about the necessity of having a safe display protected by GFCI. What you do in your house is your responsibility. Right down to the liability if someone is killed because the single device that would have prevented their death wasn't used because it caused an undesirable effect during precipitation.

Jeff

eswets
12-29-2008, 08:52 PM
Jeff and to all reading this post, Jeff is very correct with his response, I fully understand GFCI's and do not recommend any one to remove them. I didn't realize that stating I was going to remove them, others might follow. The GFCI tripping are on a display part that is only accessed by me. To where little Johnny can't get. I may have my reasons for not liking GFCI's but for the rest of the public, they do save lives. Just don't think that it will prevent electrocution 100%. As far as my display, Because of what Jeff said about little Johnny, all pieces where someone can touch will be protected (thanks Jeff didn't think of that!). Bottom line, SSR (not the lights) do not benefit from a GFCI, correct? I guess I might have gotten a little worked up after all the rain and melting snow this passed weekend. GFCI tripping everywhere and the one on the roof accessed only by a 24' ladder is the one I want to remove.
Thanks Guys

WireWrap
01-05-2009, 01:24 AM
...
I may have my reasons for not liking GFCI's but for the rest of the public, they do save lives. Just don't think that it will prevent electrocution 100%. (emphasis added)
...


This is a VERY important point! The principle of a GFCI is to remove power in the event of an imbalance in the hot and neutral sides of a circuit. If an unintended path to ground from the hot side occurs (little Johnny grabs a broken bulb while barefoot) the breaker will trip almost instantly. This is because whatever current is flowing through Johnny is NOT flowing through the neutral wire. So there is a distinct difference in currents and the circuit is shut down.

Now for a different scenario -- Little Johnny is curious and removes one of your C9 bulbs and inserts his finger to brighten his day... He's wearing his rubber boots because Mom made him. The top quality boots insulate him from the ground, so no current flows in that path -- however, his finger is doing a wonderful job of passing current from hot to neutral, so the screams accompanying the smell of smoke will continue until the circuit is opened. The GFCI has seen absolutely no reason to trip -- and WON'T!!!

So be aware of your hazards! GFCI's ARE important, but they are not a cure-all.

TERBObob
01-05-2009, 10:01 AM
I agree on the above post . I have a REN 16 that must have got some moisture inside the enclosure and man , that triac TOASTED . GFI did not kick it off ..
So , is the GFI faulty , or is this the way they are supposed to act ? ( FTR - yes , this is my first year using GFI's outside in the enclosures with the REN's . All my outside plug outlets run off one main GFI )

eswets
01-06-2009, 12:40 AM
One thing I do not understand is why everyone uses 2 wire cords to there SSR's. TERBObob the GFCI might have tripped if you had a ground in the enclosure. If you did, then a bad GFCI. All of my enclosures outside have a 3 wire cord and is grounded. Even if the lights do not have a ground pin, at least the enclosure is safer. Many GFCI go bad were they will not trip anymore and they will stay on. What happens when the GFCI goes bad in the on position (I find in my field that 50%will not trip off when bad) and you get a little water in your box somebody touches your box and it will be 4th of July instead of Christmas. Well with metal ones at least ( I have a few metal ones and yes they are grounded). Even plastic, the board will short out with water inside and as long as it doesn't make a path to the snow it is sitting on, it will just fry. If you have a ground it has a place for the stray current to go, unbalance the line/neutral and GFCI will trip. One point nobody made yet, is with outside GFCI's, moisture is very bad for them. You should test them often. If they will not trip, replace it. It does no good if it is bad.

Photovor
01-08-2009, 01:58 PM
I know we have SOOOO many threads on GFCI, I think we need to make a verbose entry on the Wiki.

Anyways- I found this, which I think is a very good explanation:
http://ecmweb.com/mag/electric_think_gfci/
Sums up a bunch of things.

Another good one with a more technical diagram of how it works:
http://ece61.pratt.duke.edu/GFCItutorial.html

If someone wants them, i have some detailed internal pictures of a GFCI that I had torn apart... opening one and seeing the mechanism and how it triggers a 'trip' is pretty neat.

djulien
01-08-2009, 02:44 PM
IIf someone wants them, i have some detailed internal pictures of a GFCI that I had torn apart... opening one and seeing the mechanism and how it triggers a 'trip' is pretty neat.

I was going to open up one of my GFCI's to see what was in it, but if you've already done that, yes, please post or send your photos.

don

Photovor
01-08-2009, 04:13 PM
I'll get some pictures posted tonight.

Warlock
01-08-2009, 06:44 PM
My input on this GFI deal is use a GFI breaker..Much safer and easier to use and wire then a GFI outlet..Great thing about a GFI breaker is it GFI'S everything on that circuit...Too many pluses to offset the cost of a $80.00 breaker instead of a $50.00 breaker...

eswets
01-08-2009, 06:57 PM
The good thing about a GFI breaker is that they don't go bad as quick as the devices that goes outside. Moisture is very bad for them so inside might give you better protection. The moisture will not get to it and cause it to fail in the on position. The bad thing is, I have 10 circuits outside all outlets on individual circuits, 10x50=$500 for GFI breakers or 10x10=$100 for GFI outlets. Or GFI the main feed for the sub panel, but one little little insome water and the whole display is out.

Warlock
01-08-2009, 07:08 PM
They sell GFi mains now in Canada anyway so you might wanna have a look at electrical supply places and see if they seel them in your area.GFI mains are reat as everything else off them are all GFI as long as they are grounded.Remove the Ground and the GFI is gone with a normal outlet..It does work....Altho it shouldn't work but it does...Just like a normal breaker..
Later..
Joe..

rstehle
01-08-2009, 08:47 PM
I found some really good buys on GFCI breakers on eBay (Brand new Square D - Homeline 20A) for about $20.00 each. They are $32.95 at Home Depot. I realize that different brands may cost more, just wanted to share what I had found.

Photovor
01-08-2009, 08:59 PM
Cooper Class A GFCI 20A 2 Pole 125V 60Hz Receptacle

Part 1 of Attachments.

Full Size (CAUTION - 2MB!!)
Cover Off - http://www.altoonalights.com/images/gfci/cover_off.JPG
Prongs Removed - http://www.altoonalights.com/images/gfci/prongs_removed.JPG
Inner Board - http://www.altoonalights.com/images/gfci/inner_board.JPG
Top of Board - http://www.altoonalights.com/images/gfci/board_top.JPG

Photovor
01-08-2009, 09:01 PM
Part 2 of Attachments

Full Size (CAUTION 2MB!!)
Trip Reset Pin - http://www.altoonalights.com/images/gfci/reset_pin.JPG
Sensing Coil - http://www.altoonalights.com/images/gfci/sensing_coil_close.JPG
Solenoid - http://www.altoonalights.com/images/gfci/solenoid_close.JPG
Solenoid Angle #2 - http://www.altoonalights.com/images/gfci/solenoid_angle_2.JPG
Trip Path - http://www.altoonalights.com/images/gfci/trip_path.JPG

Photovor
01-08-2009, 09:02 PM
Part 3 of Attachments

Full Size (CAUTION 2MB !!)
Trip Pin Detail - http://www.altoonalights.com/images/gfci/trip_pin_detail.JPG
Trip Pin Side View of Latch - http://www.altoonalights.com/images/gfci/trip_pin_latch.JPG

Photovor
01-08-2009, 09:15 PM
Ok... now that you've seen the pictures, here's how it works:

The sensing coil checks the current on both the hot and neutral, when it detects a difference in the current on both legs, the solenoid quickly pulses. This solenoid pushes a little tiny bracket forward. This bracket retains a trip pin that has downward spring tension on it. When the bracket pushes forward, it opens a small gap for the trip pin to drop through. When the trip pin drops through, it pushes down on the 2 metal contacts. When the contacts are pushed down, it breaks the circuit. This trip pin is now locked in the down position. When you push the reset button, it forces that metal bracket back, which allows the trip pin to raise back up, and slightly hang on that metal bracket again. When it raises back up, the contacts close once again, and the circuit is completed.

djulien
01-09-2009, 01:50 AM
I found some really good buys on GFCI breakers on eBay (Brand new Square D - Homeline 20A) for about $20.00 each. They are $32.95 at Home Depot. I realize that different brands may cost more, just wanted to share what I had found.

I used a couple of those little yellow portable GFCI units from Home Depot for circuits that were not already protected by GFCI. They just plug into a regular outlet. I think they were something like $18 each. They seemed to work fine.

don

djulien
01-09-2009, 02:00 AM
The sensing coil checks the current on both the hot and neutral, when it detects a difference in the current on both legs, the solenoid quickly pulses. This solenoid pushes a little tiny bracket forward. This bracket retains a trip pin that has downward spring tension on it. When the bracket pushes forward, it opens a small gap for the trip pin to drop through. When the trip pin drops through, it pushes down on the 2 metal contacts. When the contacts are pushed down, it breaks the circuit. This trip pin is now locked in the down position. When you push the reset button, it forces that metal bracket back, which allows the trip pin to raise back up, and slightly hang on that metal bracket again. When it raises back up, the contacts close once again, and the circuit is completed.

Hmm, sounds like it should be possible to replace the solenoid + trip pin with either a latching relay or N.O. relay + control circuit that powers the relay coil until the current difference is detected then cuts power to the coil, opening the circuit. Then an external signal could energize the coil again to reset the circuit.

don

Photovor
01-09-2009, 09:00 AM
It would be VERY easy to do actually, but, in hindsight, I'm not sure I'd even want to tamper with the circuit. I'm sure the electronics in there are very finely tuned. Plus you have a reliability issue with having a 'reset circuit'. Your circuit would have to sense when the trip coil was energized, latch a relay open, wait a few minutes, close the relay, and repeat.

If any part of that failed, and you had a person attached to the other end- not a good thing- and you just voided the warranty by opening the GFCI, and probably voided your homeowners insurance when you electrocuted the person, by overriding the safety device.

Tho- they'd have a better chance with this than no GFCI of course :-).

Jeff Millard
01-11-2009, 10:53 AM
The only issue I can see with trying to develop something that would be controllable remotely, is how would we prove it protects from deadly shock hazard? What does the UL use for test criteria? Timing a trip would be a simple test for me, as relay protection maintenance is my profession. I test relay circuit trip times, settings and functionals daily. This thread and the dissection of a cheap GFCI has me wondering why the diff circuit couldn't be copied, and used on an inexpensive high-speed contactor.

I don't have an engineering background, so I don't know if this is feasable... or if we're setting ourselves up. I would really be surprised if there wasn't something liek this already available commercially.

Jeff

Photovor
01-11-2009, 11:32 AM
I don't have an engineering background, so I don't know if this is feasable... or if we're setting ourselves up. I would really be surprised if there wasn't something liek this already available commercially.

Jeff


I seem to remember seeing some different interfaces out there that could monitor your breaker panel, but also had the ability to connect/disconnect any breaker circuit via a remote web interface. I'm sure someone has already designed something out there.

http://www.freepatentsonline.com/4979070.html

In another thought thread- I know there are products out there for monitoring the power for computers, in a server environment. Those devices are also controllable by a web interface. Doubt that they have GFCI versions of those though.

http://www.itequip.com/shopitem.asp?searchterm=M002255510