~Low voltage landscape lighting BURNING at splices ? (pics)

[clubkidcarlos]

Hello all,

hmmmmmmm... this one has me going.
Here is the situation.

I have a outdoor transformer with photocell.
It is a 600watt, with 2 legs of 300 watt.

The lights total 10 that are submersibles for the pond, and are 12volt, purchased from same Co.

I have the transformer about 9 feet from a central "hub" where each leg running from the transformer fractions out to 5 lights.

I'm fairly sure I'm not surpassing the 600watt max on all these lights.
What makes me a little uncertain is I think the wifey might have changed out a 35w and replaced with a 50watt, and maybe now am surpassing ?

For a year ( before wifey )... things were fine. Then, I noticed the lights starting going down. It's not every single one... just certain ones. When I lookat the splice areas what is nutty is one light spliced into another on a leg... there might be one down from that leg but not the rest ? weird..............

I have also noticed BAD burning and corrosion on the splice areas.

What could be causing all this ?

Let's say I'm not over the 600w limit....
is it bad wing nuts over the metal splice points ?
to small on the 12/2 that runs from the trans to the splice point "hub"

In the pic of the splice... that's not even half of the char that I normally see. The lights will work for a couple days,.... charge the splice.. and then back to certain lights off.

What could I amend or change to get away from such a problem ?

[HayZee518]

In a parallel circuit of lamps, voltage is constant and amperes are added. In your case the 12 volts is constant on each lamp. The current of each lamp adds together. One 35 watt lamp draws 2.92 amps, one 50 watt lamp draws 4.2 amps. If you had ten 35 watt bulbs on the line all added would give you 29.2 amps on the xfmr and ten 50 watt bulbs on the line all added would give you 42 amps. Therefore intermixing 35 and 50 watt bulbs would not add up to over 50 amp which is what the transformer is rated at. I would look to the splices as being high resistance connections. Make sure the splices are shiney and mechanically tight before screwing on a wirenut. If I were you, I'd use some al-nox on the joint. This is an anti-oxidant used for aluminum wire but works wonders for copper joints.

[clubkidcarlos]

Thanks for the advice HayZee !!!

Do I need a special type of wire nut ?
I saw some at Home depot the other day that were for OUTDOOR applications. Seemed to not have the open end like you see most common in others,.. it had a flexible plastic end where the wires push though and twist into the nut. I assume this is a moisture deterrent.?!?!?!??!

I don't know *%^$^ when it comes to specs on this stuff so excuse my dumb questions.

[HayZee518]

I imagine there is all sorts of stuff out there for terminations. Tell ya what - screw on a regular wirenut, then squirt some al-nox inside on the ends. Maybe a wrap or two of plastic electrical around the wires and wirenut. What you are striving to do is create a joint that is as close to perfect as possible and prevent airborne corrosion to the joint. Lower voltages create bigger problems.

[Snoonyb]

Using the prelubrcated wire nuts can give a false sence of security.
I encase the regular wirenuts with plumbers putty wraped in a baggy, ziptied.

[596]

You have a 600 watt load on the tranformer and the 12/2 wire. 600 watts on 12 volts is 50 amps. Your 12/2 is rated for 15 amps. This is your problem.

[HayZee518]

"596" the feeder from the transformer to the hub should be #6 wire rated at 65 amps. Each leg of each lamp is either 2.92 or 4.2 amps depending on the lamp wattage. FIVE parallel connections to the hub on one side and FIVE parallel connections from the other side to the same hub, the amperages are added voltage is constant. 5 X 2.92 = 14.6, 5 X 4.2 = 21 amps, added together = 35.6 amps

[596]

I took him to mean he had 600 watts total. But even 35 amps is way too much for 12/2, right? His drawing is labeled as a single 12/2 feeder, which leads me to wonder where is the return leg? I was assuming that each light had to be connected across the 12 volts on the 12/2, even though his drawing is not clear on that.

[HayZee518]

No his outgoing voltage is 12. Each lamp , 35 watts or 50 watts is rated at 12 volts. look at his drawing - a feeder goes from the xfmr to a central hub where splices are made, five in one direction and five in another. the way "he's" got it drawn he has five cords on one side [ when one conductor of each should be connected across both feed wires] and five on the other. In his configuration the circuit would not operate. I'll drawn him a diagram and send it here to the forum.

[HayZee518]

Low voltage wiring

Use this diagram as part as your fix for low voltage....