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I'm using an intermatic ST01 to feed the dimmer, since I don't have a neutral in the far box, and I'm told not to feed dimmed input to a timer.

From there is where I'm having a problem, using a Leviton single or 3-way dimmer (IPL06). Can I use this type of dimmer, or do I need a special one? I saw someone else posted about Lutron Skylark sf-10p working, but I don't have any experience as to which wires to use from that fluorescent dimmer, or if I even need that style.

I only need the dimmer to dim, obviously, and to cut the power from the timer to the load. I don't need it to remotely trigger the lights.

  • Hello, and welcome to Home Improvement. This is a bit confusing; would you add a diagram? – Daniel Griscom Dec 5 '18 at 16:01
  • You realize "3-way" has nothing to do with sequential controls like this where both switches must agree for the light to light (AND logic). It has to do with multiple points of control where any point can flip the switch (XOR logic). If you don't need XOR logic, avoid 3-ways. You don't need them. – Harper Dec 5 '18 at 17:04
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    @Harper The mention of 3-way might have come in simply because many dimmers now support 3-way operation (there was another question in the last day that includes one of those) as it is cheaper than manufacturing/stocking 2 different items. In other words, the OP may mean "a [single or 3-way] dimmer" and not "a single dimmer or a 3-way dimmer". – manassehkatz Dec 5 '18 at 17:53
  • Are you dimming tungsten (incandescent), CFL, LED, or a mix of the three? – ThreePhaseEel Dec 6 '18 at 0:23
  • Also, is this the answer you saw with the SF-10P in it? – ThreePhaseEel Dec 6 '18 at 0:51
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OK, so you want the lamps to be on at certain times, but dimmed.

Using old-style steam wiring, both the dimmer and the timer are devices which need power themselves. But either one would damage or cut the power the other device needs to function.

You certainly can't dim supply power to the timer, or it will be unable to do its timer thing, obviously.

Conversely, if a timer tries to turn a dimmer on and off, the dimmer will not be able to get the bulbs to "strike" at low settings. That is an artifact of how dimming works, and I'm sure you've seen this. Dimmers are designed expecting the human to go "Hey! No light!" and go to the knob and increase the dimmer light level until the bulbs strike, then back it down to the desired brightness. Well a timer can't do that, so you'll get no light at all, and leave the dimmer in a weird mode for a long time, which could damage it.

3-way wiring is certainly not constructive here, and should be avoided. 3-way human vs. timer simply makes no sense at all, and will not do anything you would want.

So let's look at options to get where I think you want to be.

Smart switches

Smart switches can do anything. You get a smart dimmer and a hub, and program the hub to turn the light on at X% light level at times Y:00 to Z:00 or whatever.

The important thing about smart switches is you only need 2 wires - Always-hot and neutral - to each location. Communication is done via radio (WiFi) and/or powerline signaling.

The smart dimmer could even be a smart socket or smart bulb. Anywhere you might want manual control, slap a smart switch there and tell the hub what you want smart switch activation to mean. Badabing. done.

Use just the timer, and smaller light bulbs

The easiest way to dim light bulbs permanently is use smaller or fewer bulbs.

The trick is, a 25W bulb is not as bright as a 100W bulb. However, light works on a log scale (decibels), so a 25W bulb isn't 1/4 the brightness. You may need to go dimmer, e.g. 10W or even 3W night lights. They make adapters to let you put night lights (E10 candelabra) into standard (E26 Edison) sockets.

If you want high-low light settings, consider adding some light sockets with pull cords so you can turn on the bright ones when you want them for work.

Low voltage LED lighting w/ PWM dimmer

In this case you use the timer normally. Downstream of the timer, you fit a 12v LED power supply, feeding a PWM dimmer module which has an external rheostat (knob) for control input. You need to select LED lights with resistive regulation, i.e. LED strips or puck lights. PWM dimming works a completely different way, and does not have the "strike" problem. Hence it will come on at any brightness.

Low voltage control wiring (i.e. From the dimmer module to the rheostat dimmer knob) can be done in plain thermostat wire. You would also have the design freedom to, say, fit a manual switch that selects between two fixed resistor values, giving two brightness settings. The sky's the limit on design because it's low voltage.

  • Bulb strike-in should only be a problem with discharge (fluorescent, halide, sodium) lighting loads -- AIUI, incandescent (tungsten) dimmers just get turned on at whatever setting they were left at and work just fine, and well-behaved dimmable LEDs should work like their incandescent counterparts – ThreePhaseEel Dec 6 '18 at 0:50
  • @ThreePhaseEel I've seen plenty of tungsten incandescents on dimmers that failed to start up if they were turned on at a low dim setting. You have to ramp them up a bit, then back them down and they will hold the low dim once lit. I suspect it relates to incandescents weird way of being nearly a dead short when unlit. – Harper Dec 6 '18 at 0:56
  • that could very well be the case... – ThreePhaseEel Dec 6 '18 at 1:02

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