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PlantscapeSolutions
09-26-2012, 01:58 PM
I loop my installs and have consistent voltage but many times I come across other system that are not looped with bad voltage ranges (14 volts down to 9). I solder my connections and once the wires get carbon buildup the flux and solder doesn't work very well. I've tried to scuff the wires with sand paper clean off carbon but it really doesn't help.

I'm uncertain if the carbon is strictly a product of excessive voltage or a combination of excess voltage being pushed (amps) to great a distance. I'd like to hear others feedback on the issue.

steveparrott
09-26-2012, 07:25 PM
I loop my installs and have consistent voltage but many times I come across other system that are not looped with bad voltage ranges (14 volts down to 9). I solder my connections and once the wires get carbon buildup the flux and solder doesn't work very well. I've tried to scuff the wires with sand paper clean off carbon but it really doesn't help.

I'm uncertain if the carbon is strictly a product of excessive voltage or a combination of excess voltage being pushed (amps) to great a distance. I'd like to hear others feedback on the issue.

Confused by your question, are you trying to solder a wire that's already oxidized to a black color? Since landscape lighting wire is stranded, it's impossible to remove the black oxidation (cupric oxide - not carbon) by sanding. Flux will remove oxidation from a wire if it's not too far gone - then it can be soldered.

If you're drawing a lot of amperage through the wire (heavy load) - it will heat up but not burn. It could be that hotter wire may oxidize faster than one with a light load - since most reactions speed up with heat.

muddywater
09-26-2012, 09:44 PM
How do you make your solder connections water tight? Why solder instead of wire nuts? Sorry if that iss off topic, but curious.

Isnt the oxidation from moisture? On a job we are repairing now, it is oxidized inside the wire two or three feet past the connection.

Lite4
09-26-2012, 10:27 PM
The oxidation is a product of a poor connection and water and minerals getting into the cable.

PlantscapeSolutions
09-27-2012, 12:54 AM
Confused by your question, are you trying to solder a wire that's already oxidized to a black color? Since landscape lighting wire is stranded, it's impossible to remove the black oxidation (cupric oxide - not carbon) by sanding. Flux will remove oxidation from a wire if it's not too far gone - then it can be soldered.

If you're drawing a lot of amperage through the wire (heavy load) - it will heat up but not burn. It could be that hotter wire may oxidize faster than one with a light load - since most reactions speed up with heat.

CuO not C interesting. I had splayed out the wires flat and tried to scuff off the CuO material but it seems the chemical reaction made flux useless. The scuffing of the wires did yield visual results but not enough to make a difference.

I guess the next interesting bit of info would be to know at what temperature does copper start to oxidize.

PlantscapeSolutions
09-27-2012, 01:01 AM
How do you make your solder connections water tight? Why solder instead of wire nuts? Sorry if that iss off topic, but curious.

Isnt the oxidation from moisture? On a job we are repairing now, it is oxidized inside the wire two or three feet past the connection.

I solder and use wire nuts. The solder pretty much turns your stranded wire tips into solid wire which allows the nuts to bite and thread. Wire nuts on stranded wire do not bite and offer no ability to keep the wires from pulling apart easily.

Soldered connections will never corrode and short out over time and you suffer pretty much zero loss loss due to resistance with soldered connections.

INTEGRA Bespoke Lighting
09-27-2012, 12:06 PM
Soldering your connections is fine (not necessary IMO) but you have not told us how you are then waterproofing those soldered connections. A simple wire nut over the soldered connection will offer no moisture protection. Without a proper waterproof connection, moisture will enter between the jacket and the copper and wick up into the cable. This moisture then causes the copper to oxidize.

PlantscapeSolutions
09-27-2012, 02:47 PM
Soldering your connections is fine (not necessary IMO) but you have not told us how you are then waterproofing those soldered connections. A simple wire nut over the soldered connection will offer no moisture protection. Without a proper waterproof connection, moisture will enter between the jacket and the copper and wick up into the cable. This moisture then causes the copper to oxidize.

I've never had a soldered and exterior use wire nut fail on me thus far. I'd dare say 75% of the companies out there simply wire nut stranded wire, tire a knot in it, possibly throw on a little tape, and walk away. Most people seem to think soldering is over kill but if I were to hear shrink or uses the 3M DBY's even I think that would be overkill.

I've done modifications or repairs to broken wires on systems that I did and the copper at the ends of the wire runs has always been as clean as the day I installed it. It's only voltage issues that have caused me to find oxidized wires and the amount of oxidation was the same at the end of the wire as it was ten feet down the line.

INTEGRA Bespoke Lighting
09-27-2012, 03:28 PM
So you put a silicone filled wire nut over the soldered connection? Somehow you must be getting water into the wire jacket or you would not have oxidation of the copper.

The copper itself is not going to oxidize from any amount of voltage that you put to it, nor will it react that way from high amp loads. Just as Steve said, a high amp load will heat the wire up some, which in combination with moisture might speed up the oxidation, but other than that... no.

Time to make better connections and keep that water out.

PlantscapeSolutions
09-27-2012, 04:21 PM
So you put a silicone filled wire nut over the soldered connection? Somehow you must be getting water into the wire jacket or you would not have oxidation of the copper.

The copper itself is not going to oxidize from any amount of voltage that you put to it, nor will it react that way from high amp loads. Just as Steve said, a high amp load will heat the wire up some, which in combination with moisture might speed up the oxidation, but other than that... no.

Time to make better connections and keep that water out.

I agree with Steve 100%. The heat caused by too many amps being being pulled through too small a wire is causing heat. The heat is causing the reaction chemical between Copper and Oxygen to happen at a greatly expedited rate. You do not need H2O from moisture intrusion in the equation to create the culpric oxide. From the uniform amounts of CuO I see over long runs of wire heat is the only thing causing the problems. The amount of Oxygen required for this to occur appears to be very finite as well. You would expect the problem to lessen the farther you get from the splice but that is really not the case.

I tend to find patina present any time Cu, O, and H2O get together.

LLC RI
09-27-2012, 04:50 PM
Interesting discussion. I too have had over the years, some wire where one or both conductors were patina coated, even a foot or more down from the end. I used to think it was the quality of the PVC jacket and that if it was poor quality ( as it was years ago with wire sold by the likes of Milspec Industries), but now I'll look at things differently.

An interesting point I will add is .... years ago, I had done a job at a condo development. The original builder ran 110 volt floods under every tree and used 1 piece of 12 / 2 romex for the whole run. NO conduit, no common sense.

Fast forward, we ran our low voltage lighting and got the system working. After it was operational, we had a couple of occasions where the lights stopped working in areas. Upon examination and troubleshooting, we found previously unknown line voltage splices which were in aluminum bell boxes and buried, which had failed.

For years, those splices sat underground unused. The connections corroded and degrade, though they still ohmed out on a meter, and carried power initially. Once the system was complete and running, the current draw through those compromised splices cause there to be arcing and subsequently, the splices failed.

Moral of the story- your system is only as good as the connections within.

And the second moral... don't trust underground wiring that you didn't put in or that is not in conduit so you could replace it. We never know what others do, how they wire, how they splice and where they 'hide' their splices. As much as you all can, on a job that has some existing wiring line or low, make it your point to sell the client on the importance of installing new wiring to insure the future integrity of the system.

George

bcg
10-01-2012, 04:48 PM
George, this is where an irrigation background is really helpful. I often find exactly what you're talking about in irrigation control wires where the solenoid ohms out fine and if you disconnect it you get proper voltage but as soon as you connect the solenoid up for a real load, the voltage drops to nothing. It's always a bad splice or a wire break inside the jacket. I can usually find the problem pretty quickly but sometimes it means running a new wire.

To the original question, I think you're seeing corrosion because of water intrusion (as others have said). You can probably get the wire clean enough to solder with a mild acid, like CLR, but if you're seeing so much corrosion that you need to acid wash the wire, I wouldn't use it. Soldering is fine if you want to take the time to do it but making the connection water tight is more important. No matter how you make your connection, I'd suggest you start using the gasket lined heat shrink to protect them. I'm amazed at how much better the wires I've used the heat shrink on look than those where I used other methods (like grease filled wire nuts) after the same amount of time in the ground.