Non-Neutral Wiring v Neutral Wiring

Hello All,

I have arriving tomorrow two of the Inovelli ZWave Dimmer Switch (red series) and I have a question about the non-neutral wiring method. To date all of my smart devices have used the neutral, and this will be my first where there is an option to not use the neutral. The load surpasses the 25w requirement, and are LED bulbs on the circuit.

I understand that no-neutral required switches are a relatively new concept compared to the traditional neutral-required option. Although I CAN hook these up using the neutral, due to position/limitations within this switch box, I’m leaning toward going with the no-neutral installation method. I’ve read the posts that I could find on this forum, but they don’t exactly answer my question.

My question is about the technical differences between the neutral-required v no-neutral required options. What exactly changed within the last couple years that made it possible for there to be a no-neutral option. For a long time it seemed like there was just no way for people to do anything without a neutral, and the “wanting to know more” part of me is that - wanting to know more about the technical information on how this became possible. Are there any other things I should be aware of (other than losing the energy monitoring possibility on the red series)?

Thank you for everyone’s help - part of me is still thinking of doing the neutral, but with this particular box/wiring configuration, skipping the neutrals would be a significant advantage for a couple reasons.

I would keep the neutral… Much less complicated / potential problems…

I agree if you have the neutral I recommend wiring it. I installed 3 non-neutral switches. 2 of them should not have needed the additional aeotec bypass with one circuit having 4 bulbs (48 watts) and another with 4 bulbs (36 watts). Both switches behaved odd, with both acting differently. I had to install the bypass for both because the switch claimed the first was only producing 4 watts and the second only 2. You may not be in the clear of the 25w threshold even if you think you are.

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For any switch to work there must be a neutral (or “return path”)

  1. Neutral requiring dimmers use the neutral wire to complete the dimmer controller section
  2. Non-Neutral dimmers use the load as a path to neutral

Older non-Neutral dimmers required too much current to power their internal circuitry the ultra low power LED lights would actually turn on dimly with the current the dimmer needed to function.

Newer dimmers (like the Red) consume much less current to operate so a low powered LED is often enough to operate the dimmer control circuit. Note some LED’s require so little power that an additional load is required the operate the dimmer. This load is in the form of Non Neutral bypass

If the neutral is available I would definitely use it… My logic is that down the road a replacement LED may not be able to power the dimmer circuit and the lights could flicker.


The product documentation indicates there are two main limitations for a non-neutral configuration.

  • Load <25W requires bypass
  • Energy Monitoring is unavailable

If these limitations aren’t a problem, then you should be fine proceeding without a neutral. That being said the load requirement does seem to present problems. You may need a bypass to prevent the lights from coming on when the switch is off. Keep in mind most LEDs are rated for maximum power, so your dimable bulbs may require >25W at 100% brightness, but only 10W at 10% power.

Thank you everyone for the information. While the non-neutral option would have made the project much easier, I decided to go neutral based on everyone’s posts.

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The strange thing for me is, I have a neutral wire yet I am experiencing flickering. The red series dimmer is replacing a Lutron CL Maestro and that switch worked fine, dimming nice and smooth.

They are wired to LEDs yes, (so low wattage) but with a neutral wire, a it shouldn’t even be an issue right? I have used the jumper to tie the switch into the neutral as well.

Anyone have any guesses what is happening?

I probably should have mentioned the common problem with a non-neutral installation is the LEDs don’t turn off all the way.

Flickering is typically an incompatibility between the LEDs and dimmer. I’ve had Lutron dimmers (non Smart) that flickered, replaced it with a Leviton and all was good. I’m not suggesting the Leviton is better, just a slightly different circuit.

There may be a better solution but the only advice I can give is to try a different LED brand.


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Hmmm… Is there a list of LED cans that Inovelli is compatible with? Kind of disappointing…

Perhaps but we won’t know if a non compatible LED is the root cause. If the dimmer works fine with an incandescent then we’'ll know.