I'm a sculptor trying to light a sculpture and want to wire a string of copper wire fairy lights into a 12 volt landscape lighting system. The lights I have are a type with a 115 volt plug in transformer, the unit says the output is 12 volts Max 0.3 amps. can I just wire it into the 12 volt system? Will I burn out the lights if not polarized correctly?

 

If the lights are LEDs then the polarity is important. Does the transformer include a rectifier to provide DC out?
It is usually written on the label.

 

Welcome to AAC.

Are the fairy lights battery powered? Solar powered? If the answer to either of those questions is yes then no - you can't just plug them into 12 volts.

Another question: Is your transformer output AC or DC? Logic dictates its AC and needs to be rectified before being regulated down to the voltage the FL's need. However, some landscaping power supplies DO have a rectified output. Most don't.

the output is 12 volts Max 0.3 amps. can I just wire it into the 12 volt system? Will I burn out the lights if not polarized correctly?

That's a very small power supply. 0.3 amps (300 mA) wouldn't be enough to light landscaping lighting IF they were using halogen bulbs. But the last point I want to make is that 300mA isn't a lot of power and you can't just put a whole bunch of lights onto it. If your landscaping lights are already running close to 300mA then the additional load may go over the limit of the capabilities of the power supply.

Oh, and yes, it must be wired correctly. Backwards MIGHT blow the lights out. But there's a whole lot more we need to consider before giving you a definitive answer to your question.

 

I've used 12V LEDs in my landscaping system, but these are made to run at 12V, and they include a bridge rectifier to convert the AC into DC inside the LED light.

So... I would advise you get yourself a bridge rectifier (best) or simply a nice diode (may flash) to make DC into your fairy light.

Note you may have to do some more work if the fairy lights are more than simple LED lights, like they blink or such.