Low voltage outdoor lights problem

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Jmcnyc

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I have had a low voltage outdoor light setup running for years. All good. Something happened the other day that tripped the circuit. When I reset the circuit and the lights go on I start to smell electrical burning and the wire cable feels hot to the touch. Then the circuit breaks.

I assume I have a short somewhere. I have about 10 lights on this transformer. How do I find the problem? Cables are all buried. Trying to fix it without to much digging. Any ideas?
 
How many watts is the transformer? What wattage are the bulbs? You may be at the top of your limits. Try removing one bulb and see if it still pops?
 
You'll have to trace the short at each fixture if you can. This way you can narrow it down 50% at a time.
 
Test for continuity at where the wires emerge at each fixture. Or disconnect the set at one fixture at a time and see if the circuit pops at any given point.

Errr, if you smell burning wire, and the wire is all underground, where is the smell coming from?
 
My guess is unless you were digging and hit some wires is that the transformer is the problem. First step in trouble shooting is to divide the problem in half. Disconnect the wires from the transformer and plug it in. if it still gets warm and trips the circuit you are in luck. If not get a volt meter and check the voltage at the output. If you feel the transformer is fine then you have to start working outdoors with the lights. A similar process can be used out there to cut the problem in half by breaking the circuit at light number 5 in the string. If it works the problem is with lights 6-10 if not the problem is with 1-5. I think you get the idea.

That’s trouble shooting 101 in a nut shell. Good luck.
 
I don't know much about low voltage lighting for gardens but logic is telling me that if the lights have been running fine and the transformer has been running fine for years I doubt it would be the total watts of the lights causing this issue.

If it were a short it would kick the breaker somewhat immediately where as overheating of the transformer may cause the breaker to trip over time (whatever period of time it happens to be; maybe more often as the transformer wears or labors). Transformers do not really have any moving parts just copper coil windings (transformers either increase 'step-up' or decrease 'step-down' voltage). Transformers can also heat up during normal operation especially much larger ones. Some are even "oil-cooled" with fins like a car radiator to increase surface area for quicker cooling during operation. And a big characteristic is that they will "hum" to some degree depending on the size etc.

A suggestion already given here to remove the lights from the transformer is a good starting point. If after you remove the lights the breaker trips then you pretty much know for sure it is the transformer and you don't have to go digging up any wires etc out of the ground or changing those lights bulbs. And honestly with some of the less expensive low voltage lights every time you remove a bulb etc you run the risk of breaking the light or doing damage to the light bulb fixture.

As asked already where is the smell coming from. Is it coming from the breaker panel or the transformer for the lights. Is this transformer the only thing on this circuit. Do you know what size breaker it is (should say on breaker). What size wires from the breaker?

Would you be able to post the make and model number of the transformer for us please.
 
Thanks for all the responses. I am going to try and diagnosis it this weekend. Some of you asked how I can smell the wire burning - there is a section that comes off the transformer before it goes underground. This section of the wire is hot to the touch. I am assuming that the smell comes from here, but it could come from a light unit. I didn't spend much time trying to figure it out before I unplugged it.

The transformer unit is model BPL-300W-12V - https://www.amazon.com/dp/B001T94BP6/?tag=skimlinks_replacement-20
 
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Thanks for all the responses. I am going to try and diagnosis it this weekend. Some of you asked how I can smell the wire burning - there is a section that comes off the transformer before it goes underground. This section of the wire is hot to the touch. I am assuming that the smell comes from here, but it could come from a light unit. I didn't spend much time trying to figure it out before I unplugged it.

The transformer unit is model BPL-300W-12V - https://www.amazon.com/dp/B001T94BP6/?tag=skimlinks_replacement-20

Ok, just spent a bit of time researching this transformer.

As mentioned transformers do get "warm" and even "hot" at times and because of the heating they may tend to give off a "smell". You will also hear a buzzing or humming noise from most depending on the size.

There is very little information on the net about this specific transformer sold by "Best Pro Lighting". Mainly all I get is the listing from Amazon and if you look at the specs it really does not tell you much at all about the electrical specs. The height, width, depth dimensions are way out of line - really 500"? This comes from site: Find Lighting Supply - HERE and the dimensions of the transformer are listed as
WIDTH500''HEIGHT1050''LENGTH500''and again showing the only picture I have been able to find on the net for this transformer.

Other sites here and there I read a lot of "broken English". Although the picture ( meaning the only picture anywhere I could find of the until at all) does in fact have the "UL" stated on it; but unfortunately that does not mean it has been tested and approved by UL. Any company can print "UL" on their product. The big test to determine if it is really "UL" rated is if it causes a fire and your home owner's insurance company investigates it to verify if it is UL rated. If the unit causes a fire with damage and you put in a claim to your home owners insurance company and they find it is not UL rated; well you get the picture.

Again, my nose goes up because of the broken English and the same "one" picture on all the sites I can find it on, which really is about 3 at most.

As your nose it sniffing "electrical" burning, my nose is smelling a cheaply made (overseas), very well possible not tested and approved transformer by "Underwriter's Laboratory" unit.

Every where I look I only see "one" picture of this transformer and it is the exact same picture no matter what site you see. There is very little "electrical information" (specifications) in the product details on any site with the exception of maybe the size of it and how well "Best Pro Lighting" claims it performs.

So far the reviews are not too bad on this unit but I have this feeling that it may not be in fact really tested and approved by UL. The reviews are by "consumers".

Heck, I could be wrong, but again my nose is "smelling" something else here.

My advice - Keep it unplugged.

ok so it seems the decimal point was left out of the dimensions of the listing.
 
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A replacement transformer bought at the big box stores is easily returnable. Buy one, try it out and if the problem goes away, it's solved. If the problem persists, you can return the new transformer and test the other components.
 
Jmcnyc: What slownsteady said about buying one at a big box store makes a lot of sense.

What is your skill level working with electrical - do you feel you would have to hire an electrician to swap it out?
 
From what I gather, it could be the transformer. It could also be one of the lights is beginning to fail. It could also be a loose connection or damaged wire. I would disconnect the suspect cable from the transformer and turn it back on. Assuming there's multiple cables on that transformer, if the smell goes away, you narrowed it down to something downstream. If it still smells, it's the transformer.
 
From what I gather, it could be the transformer. It could also be one of the lights is beginning to fail. It could also be a loose connection or damaged wire. I would disconnect the suspect cable from the transformer and turn it back on. Assuming there's multiple cables on that transformer, if the smell goes away, you narrowed it down to something downstream. If it still smells, it's the transformer.

If this doesn’t work try post number 5 again. :p
 
I strongly suggest what "bud16415" states in the above post #12 :agree: :rofl:

"Wink Wink" Bud :clap:
 
Clearly a great case of great minds working alike. :)

Bud, I don't know. This seems to have happened to you in the "recent" past also. This POST #18.

:rofl: Maybe you should add more "smilies" to your posts so that they stand out more :beer:

Just my :2cents:
 
Bud, I don't know. This seems to have happened to you in the "recent" past also. This POST #18. Maybe you should add more "smilies" to your posts so that they stand out more

Just my

I think I figured out the problem. My Romulan cloaking device has been set way to high on this forum. As an Admin I just set it back to 3 and we can see if that helps. :worthless::worthless::worthless::worthless:

Max out the smiles captain, I;m given her all I got.
 
...Max out the smiles captain, I;m given her all I got.

Yup, maxed out on "smilies" happened to me too.

Although -

I believe the correct phrase is

Scotty to Captain Kirk: "I'm Givin' Her All She's Got, Captain!"

Sorry, I guess I am going off topic here :nono: . Sorry moderators :cool: , please be "gentle" on me.
 
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Ok so I went to Home Depot and bought a 300W transformer. Replaced the existing transformer. When I turned it on The cable from the transformer to the first light immediately got very warm. The first and second light turned on. As did the third. After about 5 seconds the third light flickered and shut down. I replaced the new transformer with the old and got the exact same behavior. So I assume I eliminated the transformer as the culprit.

So now I should disconnect each light and then reconnect one by one? Agree?
 
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