DiyLightAnimation

Fun => The Porch => Topic started by: zwiller on May 07, 2012,

Title: 12V transformer tripping GFI
Post by: zwiller on May 07, 2012,
I figured since there will be alot of aether II's in commission this year some might benefit from this. 

I have a 12V lawn transformer feeding deck lights.  The tranny is wired to a GFI (not plugged in).  Works fine, but when it rains or sometimes for no reason at all the GFI trips.  Kinda reminds me of incans and art easel mini trees   ::)  It obvious is a pain having to reset the thing almost daily.  Really would like to fix. 

I originally did not wire the transformer to the GFI protection but thought "it was the right thing to do".  It's been a while since I wired it but I wonder if I wired it right (used GFI instructions).  Shared neutral maybe? 

Does anyone have any experience fixing something like this?  THANKS
Title: Re: 12V transformer tripping GFI
Post by: caretaker on May 07, 2012,
Two reasons the GFI is tripping, one it is picking up a ground fault (ratio of current coming back on the neutral) which exceeds the threshold of the device. Two the device is defective or to sensitive.  Most cases it is reason one and how you can prevent the ground fault is one make sure all the 120 volt connections to the transformer are sealed from moisture and use a in use cover with the GFI if it is plugged in outdoors. If it still trips when wet or damp try covering the transformer or moving so it doesn't get rained on.  If it still trips replace the GFI.
http://www.homedepot.com/h_d1/N-5yc1v/R-100173013/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=in+use+cover&storeId=10051
Title: Re: 12V transformer tripping GFI
Post by: zwiller on May 07, 2012,
Thanks Jeff.  Pretty sure everything is watertight.  No in-use cover since nothing is plugged into the recpt.     Tranny is mounted underneath the deck in a wet free area. 

However, I just remembered I have a photo sensor to kick on lights.  Could that be a factor?   

This is all kinda bizarre since I just left the tranny for the aethers outside unprotected all winter with rain and snow and no problems...   

For some reason I bet if I didn't wire the tranny and just plugged in the the thing with an in use cover I would be fine.  But that wasn't cool enough for me  ;D
Title: Re: 12V transformer tripping GFI
Post by: gatorengineer on May 07, 2012,
I had a similar issue when I was running my lights.  I dried out some connections and sealed them and the GFI stopped tripping.

To expand on caretaker, the exact current difference is 5 milliamps between the hot and neutral.  That is very small.  So it doesn't take much leakage current to get into some water and trip your breaker/receptacle.

Have you tried plugging the circuit into a non-GFI receptacle and see what happens.  If it runs, then you have something faulting to ground and since you said it happens when it rains, that is classic ground fault.  Somethings getting wet or something is getting moisture in it which is causing the problem.

If you think it is the transformer, then put it on some rubber or something to keep it from grounding itself that way you can track down the problem.  If the problem is inside the transformer and the case is grounded, that might be where the problem is.  You will just have to narrow it down.
Title: Re: 12V transformer tripping GFI
Post by: dudehenry3 on May 07, 2012,
Do you have any other outlets on the circute that may be getting wet as well. Dose the transformer have a timer on it if so the motor may may be bad. 
Title: Re: 12V transformer tripping GFI
Post by: tbone321 on May 07, 2012,
The easy answer is not to use GFCI there especially since it isn't doing anything for you in this situation. 
Title: Re: 12V transformer tripping GFI
Post by: zwiller on May 09, 2012,
Thanks for the replies. 

So, I decide to go tbone's way and forego the gfi protection.  I shut the breaker off and open the cover and I see the attached.

Obviously, the previous cover was a problem.  Hopefully THE problem.  So I installed an in use cover for added protection.

Also, I had problems with my deck lights not coming on when they weren't blown, go I got a small packet of dielectric grease at auto parts store and gave the bulbs a dab on contacts before installing for good measure. 

(fingers crossed)
Title: Re: 12V transformer tripping GFI
Post by: tbone321 on May 09, 2012,
The thing is that there is no GFI protection on the secondary side of a transformer.  All the GFCI will see is the primary side and has no idea what is happening on the other (output) side.  The replacement cover may help if water is leaking in and giving some of the current that the GFCI is monitoring a different path to ground.  Putting grease in the sockets may help to prevent the contacts from corroding or prevent minor shorting issues but will not have any effect on the GFCI issue since they are on the secondary side of the transformer. 
Title: Re: 12V transformer tripping GFI
Post by: n1ist on May 09, 2012,
If you look at the bottom of the GFCI in the picture, it's obvious that water did get in.  So in this case, replacing the GFCI and the cover should fix the problem.   You are right that the GFCI won't protect the secondary of the transformer, but that should be current-limited anyway.
/mike
Title: Re: 12V transformer tripping GFI
Post by: zwiller on May 09, 2012,
I only wired the transformer to the GFI because I knew it could be done and I hadn't done it before.  I could really care less for the GFI protection...  Thought it was cool that I could do that.  Maybe even some day I could use that knowledge for something... 
   
But,

while we're at it... 

The direct wiring of the transformer is up to code even if not fed by GFI right? 
Title: Re: 12V transformer tripping GFI
Post by: caretaker on May 09, 2012,
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I only wired the transformer to the GFI because I knew it could be done and I hadn't done it before.  I could really care less for the GFI protection...  Thought it was cool that I could do that.  Maybe even some day I could use that knowledge for something... 
   
But,

while we're at it... 

The direct wiring of the transformer is up to code even if not fed by GFI right?
Ummm No, technically everything connected to outside outlets needs to be protected by a GFI.  That said what you did will be fine just don't touch the transformer when it's wet.  :o  Also GFI's in outdoor or damp settings should be of the new WR type. Basically the companies that make GFI's found out there they all fail after a short time outside due to corrosion from dampness and water so the WR ones are better sealed and have corrosion proof contacts.  On another side note I think I have found only one or two weather proof boxes that were exposed to water (rain, sprinkler, etc) that stayed dry inside. I often drill a tiny 1/8th to 1/4" hole in the bottom of the box to let water out unless the box is at or close to ground level. 
Title: Re: 12V transformer tripping GFI
Post by: Night Owl on May 09, 2012,
I did a little Googling and I fuond this on the Malibu Lighting website FAQ on transformers:

I do not have a Ground Fault Circuit Interrupter (GFCI) outlet outdoors. Can I use a regular outlet?
No. Per UL1838, the outlet must be GFCI. If not, the user must replace the outlet themselves or have an electrician do it. Also the outlet must be covered with an in-use weatherproof cover.

UL1838 is the UL standard for low voltage landscaping lighting systems.  Did your transformer originally have a plug attached to it?
Title: Re: 12V transformer tripping GFI
Post by: zwiller on May 09, 2012,
Of course it had a plug...  But how cool would plugging a cord in be.  ;D

For the record, the gfi is feeding transformer primary. Not sure what the technical term is. 
Title: Re: 12V transformer tripping GFI
Post by: Night Owl on May 10, 2012,
If it had a plug on the end and you removed it, then I'm pretty sure that direct wiring up it to your electrical system is not in compliance with the electrical code, with or without the GFI.  I say this because the power cord was probably not designed or approved for direct connection to the house wiring. 

I had a GFI that kept tripping.  The foam gaskets on the outlet covers had decayed to the point that it wasn't keeping the water out.  I replaced the outlet and swapped out the cover with one that protects even with things plugged in.  I found out that these covers were required by the electrical code.   
Title: Re: 12V transformer tripping GFI
Post by: dudehenry3 on May 10, 2012,
By code it should have a plug on it yes.It is in the NEC code .As a safety also known as a disconnect.You would not hard wire your vacuum in the house. >.d9
Title: Re: 12V transformer tripping GFI
Post by: Timon on May 11, 2012,
Let me be very blunt. Under no circumstances should you run without a GFCI. Your not only risking your own life but those of your family, friends and those watching your display. If someone gets shocked or killed your going to be responsible. You maybe even criminally responsible if it comes to light that the GFCI was removed.

If you can't or don't know how to fix the problem then please hire a licensed electrician. It's a small price to pay to save someone's life.

I'm sorry if I'm rubbing someone the wrong way but life is too fragile to not be blunt about this.
Title: Re: 12V transformer tripping GFI
Post by: chrisatpsu on May 11, 2012,
also rememeber depending on how soon your state adopts the newest NEC.  there are now outlets that have plastic covers inside where the prongs go. cccthat only open when the two main prongs are pushed in at the same time.  If your state adopts the NEC quickly, you might be required to use these plugs if you change your permanent outlets. (Pennsylvania is 3 years behind the current)
Title: Re: 12V transformer tripping GFI
Post by: tbone321 on May 11, 2012,
As they say, paranoia will destroy ya.  The only thing that GFCI will protect in that situation is the transformer itself.  I am not a big fan of GFCI in temporary outdoor displays because to put it simply, they were not designed with that in mind and really don't work well in that situation.  Don't get me wrong, I would never tell anyone to stop using them or to disable existing ones but being paranoid about them is not much of a help either.  I really cn't think of a situation where they would be much of a help in protecting an outdoor Christmas light display, at least with the way mine is configured.
Title: Re: 12V transformer tripping GFI
Post by: t.jo13 on May 11, 2012,
Here is another option for gfi, Picture enclosed. I took an outdoor 60 Amp sub panel and put 3 of them in it . I also put one in the house panel for all outdoor outlets on the house and also put protective covers on all outdoor outlets
Title: Re: 12V transformer tripping GFI
Post by: zwiller on May 11, 2012,
In a lame attempt to derail the age old GFI or not debate, I am happy to report that it has rained several times since my upgrade and no trip (knocks on wood).

Title: Re: 12V transformer tripping GFI
Post by: t.jo13 on May 11, 2012,
Quote
In a lame attempt to derail the age old GFI or not debate, I am happy to report that it has rained several times since my upgrade and no trip (knocks on wood).

Same here. Fried some equipment and lights then did upgrade. no prolems for rest of  season .  :)
Title: Re: 12V transformer tripping GFI
Post by: Night Owl on May 11, 2012,
The GFI is NOT meant to protect your equipment.  It is meant to protect you and anyone around that might get electrocuted or shocked.  It detects current going out and coming back in.  If there is a difference, then there is a path to ground somewhere.  Electricity will take the easiest path to ground.  So say you mount the transformer on one of your railing posts.  A slight drizzle causes a tiny short and the electricity runs through the wood of the deck.  Someone below the deck is standing on wet grass and leans against the deck support post.  Their resistance is lower than the concrete footer that the post is sitting on.  So the current flows through that person to ground.  A GFI would detect the leakage and trip (probably before the person touched the post), a standard breaker would not.

It is indeed your choice to use a GFI or not.  Personally speaking, I rather have my show go dark because of a tripped GFI than have someone hurt or killed.  Paranoid?  Sure, you can call it that.  I'll take that label any day.
Title: Re: 12V transformer tripping GFI
Post by: t.jo13 on May 11, 2012,
I am aware that GFIs do not protect equipment, but I live on A corner lot and people cut the corner through the yard. After seeing the damage done to some of my equipment caused by moisture, I decided to caution on the safe side for everyone.
Title: Re: 12V transformer tripping GFI
Post by: Night Owl on May 11, 2012,
@t.jo13:  Sorry, my post wasn't meant as a response to you.  It seemed like some had a misunderstanding on what a GFI was for.
Title: Re: 12V transformer tripping GFI
Post by: tbone321 on May 11, 2012,
If you were talking about me then I'm fully aware of that a GFCI is and what it's used for.  In case my statement before wasn't clear and I can see now that it probably wasn't, let me clarify it.  I really can't think of a situation where they would be much of a help in protecting a person from a shock in an outdoor Christmas light display, at least with the way mine is configured. 
Title: Re: 12V transformer tripping GFI
Post by: Timon on May 12, 2012,
And there in lies the problem.<yk..