Countdown timer switches with no neutral wire requirement

[scanchain]

I was shopping for a countdown timer switch for my bathroom ventilator and noticed switches that advertised "no neutral wire requirement".

My question is -- how do they work? Are they using the ground wire as a return to power the timer? I'm pretty sure that's not allowed.

Or maybe, on pressing any button, it first completes the circuit to power the electronics and then blinks the LED on the switch. Do they have a capacitor to store electrical energy?

 

[alfredeneuman]

I was shopping for a countdown timer switch for my bathroom ventilator and noticed switches that advertised "no neutral wire requirement".
My question is -- how do they work? Are they using the ground wire as a return to power the timer? I'm pretty sure that's not allowed.

They're purely spring wound mechanical timers.

 

[Meursault74]

I installed a remote controlled light switch with no neutral wire. It completes the circuit always but when "off" there is only a trickle of current through the light bulb, not enough to illuminate it.

 

[scanchain]

They're purely spring wound mechanical timers.

Not those. I'm referring to this

https://www.amazon.com/dp/B007BJULYS/?tag=atomicindus08-20

 

[AntonLargiader]

From the manual: "Once power is restored it will take about 1 minute to fully charge. The timer will not function until it is fully charged."

 

[scanchain]

From the manual: "Once power is restored it will take about 1 minute to fully charge. The timer will not function until it is fully charged."

Assuming this charges a capacitor to power the electronics, I am curious where is the "ground" for the electronics? Is this connected to the ground wire?

 

[yatg]

Its not magic wireless electricity.

Easy direct wire installation; DOES NOT require a neutral wire (Ground wire IS REQUIRED). Ratings – 125VAC 60 Hz: 6.4A Resistive, 800W Tungsten, 800VA Ballast, 1/4 HP

 

[AntonLargiader]

Assuming this charges a capacitor to power the electronics, I am curious where is the "ground" for the electronics? Is this connected to the ground wire?

It probably grounds through the inactive load to charge. Once the load is energized that ability goes away, hence the verbiage in the manual.

I think it's not allowed to ground the electronics through the ECG. That came up with a Leviton tech support guy about ten years ago when I was asking a question that was nearly identical to this one.