[4seasons]

ok guys and girls, here is my problem.
I installed a job last november or december-- 18 lights with a 600watt transformer. 3 path lights keep going out after a few weeks. 2lights I'm sure are on the same run, but the 3rd light is on a seperate run. The 1st time I went to check on them, I accidently bumped the fixture and it came back on. The 2 on the same run did that. The third light I swapped out bulbs. 6 weeks later same thing

So I was wondering do you think the fixtures have a short in the causing this?
When I was testing wattage I took awhile for the tester to pick up anything on the fixture.
thanks in advance.


Bruce

[Dragonfly]

Replace one with a new fixture and see if you still have the same problem.

[Pelican]

I think what you are seeing is oxidation of the bulb contacts which prevents them from getting power. My first job with low voltage lights I experienced this. You'll have to remove the bulbs, buff the wire contacts lightly with fine sandpaper, then reinstall using dielectric grease which can be found at an auto parts store. This will prevent the oxidation from reoccurring.

[4seasons]

I was thinking of doing both those things. thanks for your replies.


Bruce

[GLAN]

Yeah sounds like the contact problem Pelican mentions.....

But if the bulbs are burning out prematurely my guess is they are closest to the transformer and receiving higher amperage causing the element to burn out faster.


Many of the manufacturers are aware of that problem and are making regualtors that are either add on or built into the fixture

[PSUscaper]

I've always found with mr16 bulbs they need a slight tap to get them going, then their fine. I can't see corrosion taking effect that quickly though.

One of my guess would be the light fixtures. Not for nothing, and for the fact of the price of them, they are put together like junk. Ever take one apart. There's a wire the thickness of hair spot welded to a spring underneath the bulb......And half the time the lights threads are already stripped when they were assembled at the factory.

What brand lights are these??? I'm thinking a junky batch of lights (who nows what min. wage person put them together that day!)

[4seasons]

the bulbs dont even look burned out. the fixtures are a pathlight made by hadco the rl4 i think

hadcos book says if voltage is less than 10.8 mr16s are adversely affected. might be the problem. when installed everything was 11.8-10.8 now the 3 lights are reading low 10s. so I will go to the transformer and make sure the connections are good

[Inspired]

Originally posted by Pelican
I think what you are seeing is oxidation of the bulb contacts which prevents them from getting power. My first job with low voltage lights I experienced this. You'll have to remove the bulbs, buff the wire contacts lightly with fine sandpaper, then reinstall using dielectric grease which can be found at an auto parts store. This will prevent the oxidation from reoccurring.

Test the bulbs with an ohm meter. Looking at them doesn't always tell the story. (If you have resistance, obviously you have a good bulb.)

I think Pelican is giving good advice here. I made it part of our standard installation proceedure to use dielectric grease or RTV silicon on ALL outdoor lighting jobs. It doesn't take much, but make sure you coat the pins completely just before slipping the bulb into the socket. Just pushing the pin into the nozzle end of the tube works pretty well. Depending on the brand of lights the silicone will help hold the bulbs in place if the maintnance guys have a habit of kicking or tripping over the fixtures. I began using silicone over 8 years ago and after many bulb changes (we maintained lighting systems alsol) I've found it helps the socket life as well.

The next step of course is the wire connection. Have you guys figured out yet that the little "in-line quick connectors" most companies provide with the lights are junk?

Hope that helps...

Bill

[4seasons]

I ended up using the grease also. bumped the lines that were low to a higher volt and got the lights to read 11.5
havent had a problem since(fingers crossed)


Bruce

[nightscapespaul]

When installing a lighting system, put all runs on the 12v tap of your multi tap transformer. When you have the entire system insalled, go back and make your voltage corrections. You may have to do this twice. As you add more fixtures to a system, you put a higher demand on the transformer, causing more voltage drop. You can't get true voltage measurements until the entire system is up and running. You should try to achieve 10.8 to 11.5 volts to each fixture.
If you use this procedure, you should have less problems with your lighting systems.