Halogen cabinet lights and PD-6WCL

[tannebil]

I've installed about 5 of these dimmers previously without any issue but I'm scratching my head with the latest one. All the others were 3-way but this one is a single pole for some halogen cabinet lighting.

The box has a neutral and the current switch is a Simply Automated UPB dimmer which uses the neutral and works fine. The load is eight small halogen bulbs installed in two built-in display cabinets.

I flipped the breaker, removed the existing switch (brown, black, white, bare copper), hooked up the ground and two black wires on the Lutron, and put the wire nut back on the neutral. Flipped the breaker back on and nothing. I tried another switch and the same thing happened so I figure I've got a different problem.

Doing a bit of research leads me to believe that it's likely the circuit feeds a step-down transformer which powers the bulbs. Would that cause the problem I'm seeing? Is that a 99% probability or do I need to dig into the fixture to confirm there is a transformer? Does that mean I need to use PD-6ANS switch or PD-5NE dimmer instead of the PD-6WCL with the fixture or do I need to be looking at something else entirely?

[tannebil]

I pulled a bulb and measured the base. It's a G4 and all the G4 bulbs I've found on the Internet are 12v. So I'm thinking there's a 120v-12v step-down transformer in the fixture. I found some other info related to transformers for fireplaces that says a dimmer for a transformer has to use a neutral so I've ordered a PD-5NE instead.

[tannebil]

The PD-5NE worked. It was a bit odd as the lights came on when I flipped the breaker on but the switch couldn't turn them off or change the dimming level. Changing the phase to ELV fixed the problem. I flipped the breaker off when I put the switch back in the wall and the same problem recurred when I turned the breaker back on so I had to change the phase to ELV again. Makes me wonder what's going to happen after a power failure or the next time I flip the breaker. I'm hoping that maybe there's some on-board power that needed to get charged up to save the setting to some non-volitile location.

[Blurum]

@OP Curious, How do you actually change the phase on the dimmer?

- - - Updated - - -

@OP Curious, How do you actually change the phase on the dimmer?

[joejsullivan]

www.casetawireless.com/change_phase