12 V Landscape lighting dimmer plug

Guys and Gals, I have a low voltage 12V-15V transformer for my landscape lighting. The transformer has a plug in it for a mechanical timer. I was using an Inovelli Zwave dimmer plug (NZW39) for a few months but it stopped working tonight. Earlier today I added 3 more lights and changed it from 12V to 15V but the transformer breaker kept switching off so I went back to 13V and I guess that caused the Inovelli dimmer plug to fail.

I’d like to plug in a Zwave dimmer plug to allow me to control when the lights turn on and dim them to a certain level like I did with the Inovelli dimmer plug.

What zwave plug will work in this application?


Sorry, I’m confused. It’s a transformer brick which is 12 V on the output side, but what is it on the input side? Or is it 12 V on the input side?

Also, are you plugging it in outside? If so, is the outlet inside a weatherproof box? Or exposed?

And if you are plugging it outside, what are the temperature ranges and typical weather?

Also, is the landscape lighting rated dimmable?

Thanks for the reply. This is the transformer…


It is located in my garage and it plugs into a 120V outlet. Inside the transformer cabinet is a plug for timers (see the link for a pic). I was using the Inovelli and it worked great for controling when the lights turned on and it was set to dim to 50%. It worked great for a few months then failed tonight. I’m guessing it was outside it’s specs somehow.

What would work better in this application.

I hope this helps explain the set up better!


I don’t see anything in the specs for that transformer that says it’s compatible with a dimmer. Most MLV transformers are not. They will sooner or later burn out the dimmer, which is what probably happened to you.

So the first thing I would do is get in touch with the manufacturer of the transformer and see if in fact it can be plugged into a dimmer switch and if there any special specs required.

There are multiple different kinds of dimmers, but usually that’s only for office buildings and stuff like that. It just gets complicated.

Again, what kind of bulbs are you using with it? ( incandescent, Halogen, fluorescent, or LED)

But first things first: find out from the manufacturer whether it is safe to plug that transformer into a dimmable socket. If they start talking about Lutron, that’s because Lutron has a patented line of dimmers that can handle most transformers. But most regular dimmers cannot.

A dimmer controlling an inductive load such as a magnetic transformer is also subjected to large voltage spikes and current surges.

I have my 12V AC dimmable LED landscape lights connected to a Z-Wave dimmer. Here’s what I would do…

  1. Rip out your current transformer and replace it with a quality hardwire magnetic transformer unit that supports dimming such as (https://www.totaltransformers.com/review/product/list/id/7584/) or the equivalent based on your capacity (wattage) needs.

  2. On the 120V AC side feed the transformer with a magnetic low voltage capable Z-Wave dimmer such as (https://byjasco.com/products/ge-z-wave-plus-wall-smart-dimmer). Make sure the dimmer supports LED and magnetic loads. You will need to connect a neutral.

In a way it is not much different than MLV interior lights that support dimming.

End result will look something like this:

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Sorry to bump this thread but I need some help with some capacitor math…

I already have a full 12VAC landscape lighting setup that dims perfectly as seen in my setup above. Problem is, I recently had a bunch of hardscaping done and my contractor installed some solid state LED step lights that are BRIGHT. Way too bright. There aren’t replaceable bulbs, only a solid state module that can be replaced, so lower wattage bulbs isn’t an option.

Am I correct in assuming a capacitor in series with this branch will get the job done? That being said, I have no idea what math I should be doing to get say a 1/3 reduction in brightness. I realize I’ll need to experiment with different capacitors as every LED is somewhat different, but how can I ballpark it? The branch circuit is 24W total.


My antiquated electrical engineering skills would tell me that you need to step down the voltage to the LED using a resistor. What kind of resistor depends on how much voltage is going to the LEDs and it’s rated value.

You could start here

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