The LED light string is labeled for Indoor/Outdoor use but there is a warning on the box that the transformer must be indoors. That seems as though the light string is NOT suitable for outdoor use. I want to use this string on an outdoor holiday star with the power source connection an outdoor receptacle. Do I need to return these lights for Outdoor rated use lights? Is there a fire or electrical shortage shock risk with using these with the transformer outside?

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    is the warning label unclear to you? ... the transformer cannot be outside ....... if you cannot have the transformer inside, then get some other light string
    – jsotola
    Nov 7, 2020 at 21:17
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    It's probably not a transformer, it's a power supply. What is the working voltage? Is it UL listed? Was it bought retail or via mail order? (lotsa junk on mail-order especially Amazon because of their Amazon Marketplace). Nov 7, 2020 at 21:28

3 Answers 3


Actually this warning can be for wire wound transformers and switching power supplies that do not have a protective shell where water and or moisture can damage the device. Adding a water / moisture tight enclosure with approved sealing grommets or bushings would be a code legal way to do this.

In most cases a NEMA 3R case will be sufficient. In all cases A NEMA 4 -4x weather proof is enough this is normally what we use in areas close to where vehicles are pressure washed or steam cleaned to protect the controls.


The light string is suitable for outdoor use.

The transformer/power supply is not suitable for outdoor use, and must be placed inside.


They just want you to use it in a place where the outlet is under the eves, and your winter is snow. So that it's not hosed down with water. The "indoor" is to keep dummies from returning the string when they put it outside in a temperate climate during the winter and it gets rained on.

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