Finicky Landscape LED Fixture mixed with Halogen Fixtures 12v

Status
Not open for further replies.

mark32

Senior Member
Location
Currently in NJ
I stopped by a regular customer of mine to wire in a new LED landscape fixture she had purchased. After doing so, we turned on the transformer and all the existing lights worked but this new one. Now, my splices are always 100% :) but I took the wire nuts off the splice just to check, it looked good, hmmm. While sitting there I touched the LED lead's to the, now apart, LV cable runs, and it lit up! I then spliced it all back together and it didn't work. This LED would only work when I disconnected the downstream fixtures! Anybody encounter this before?
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
The LEDs have a specific minimum voltage, below which they will not conduct. and to minimize power losses in the driver you try to keep the supply voltage close to that value. That means that a drop in voltage, either in the transformer or IR losses in the wiring, can go below that threshold value.
Possibly the original installation came close to or exceeded the transformer rating, bringing the voltage below nominal.
 

mark32

Senior Member
Location
Currently in NJ
The LEDs have a specific minimum voltage, below which they will not conduct. and to minimize power losses in the driver you try to keep the supply voltage close to that value. That means that a drop in voltage, either in the transformer or IR losses in the wiring, can go below that threshold value.
Possibly the original installation came close to or exceeded the transformer rating, bringing the voltage below nominal.

Dang you're smooth, I never would have thought of that. It makes sense though as this LED is near the end of a layout that was ill designed; no doubt there is a good amount of VD at it's location. Thanks Gold!
 

ActionDave

Chief Moderator
Staff member
Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
Dang you're smooth, I never would have thought of that. It makes sense though as this LED is near the end of a layout that was ill designed; no doubt there is a good amount of VD at it's location. Thanks Gold!
If Gold is right, and there is a very good chance he is, set up the landscape lights in a ring circuit and it may solve the problem.
 

mark32

Senior Member
Location
Currently in NJ
If Gold is right, and there is a very good chance he is, set up the landscape lights in a ring circuit and it may solve the problem.

Thanks Dave, that's a good idea. More than likely though, I'm going to suggest to the homeowner we just remove a light or two upstream of the LED. I think she'll go for it, she's not too picky.
 
Status
Not open for further replies.
Top