I'm planning a low-voltage monorail light system, fitted with 10x 7.5W 12V AC LED light heads. The manufacturer provides a "remote electronic transformer", and the installation instructions call for "remote but accessible location" for the transformer.

Can I put such transformer in the attic space above the room?

The attic is insulated, so the transformer will likely need an additional enclosure box (like this)

I looked up the California Electrical Code 2016 but couldn't find a paragraph which would explicitly allow or disallow such installation (and everything <1000V is considered low-voltage by the code, which doesn't help with search)

Besides, the attic space gets quite hot during the summer, and the transformer has a thermal shut-off. So maybe it is not a good idea to put it there anyway.

The alternative option I have is to install the transformer inside a closet nearby, but again I'm not sure whether this would be allowed by code.

  • Being over 55W, the low voltage exemptions won't fully apply. – Harper Dec 26 '18 at 20:13

Your attic is an accessible location that looks like it is already housed so all you will need a box for the connection to the power according to the instructions. Additional enclosures should not be needed.


The term "low voltage" is used differently in different contexts. In this case the low voltage part is the 12VAC output of the transformer supplying the monorail.

The transformer in your link is in an enclosure that can be mounted anywhere you can get to it without cutting drywall or otherwise ripping something apart to get to it. Your attic would be fine from an accessibility standpoint but so would your closet. It would not be OK to install it between the studs in a wall you're building, then sheetrock the wall so you can't get to it any more.

Although the spec sheet on the link page doesn't have operating temperature info, it's likely that the transformer is rated for attic temperatures, but you'd have to contact the manufacturer for that information.

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