Bathroom Fan Signal wire

[Nicksab]

I am wiring a panasonic whisper green select FV 11 15VKL1.

However, I am encountering an issue regarding the 2 red signal to manually override the fan.

Would you treat the wire as low voltage or just use a 12-4 romex and mark the wires accordingly?

Thanks

 

[Bob V]

I looked up the wiring diagram. I am discouraged by the marking that the switch wires are non powered, since the diagram clearly shows one side of the switch connected to the neutral conductor. Although this conductor is not "live", it is part of the 110 volt circuit.

I would run a NMC or whatever method you are using and call it a day.

 

[curt swartz]

We run 14/2/2. Black and white for constant power. Red and white/red stripe for control.

I have always like Panasonic fans but I think the electrical design of the newer high tech fans is as dumb as you can get. Why have a pair of control leads connected to the grounded conductor. Why not just use a constant hot and switched hot? A simple 14/3 or 12/3 from switch box to fan.

 

[Nicksab]

We run 14/2/2. Black and white for constant power. Red and white/red stripe for control.

I have always like Panasonic fans but I think the electrical design of the newer high tech fans is as dumb as you can get. Why have a pair of control leads connected to the grounded conductor. Why not just use a constant hot and switched hot? A simple 14/3 or 12/3 from switch box to fan.

That s exactly what I thought about using.

Do you re-identified the red and red/white as signal wires though?

I could not agree more about these fans. They are all bells and whistles but the wiring could be much better. Maybe some kind of remote control to override the fan would be great.

 

[Nicksab]

I looked up the wiring diagram. I am discouraged by the marking that the switch wires are non powered, since the diagram clearly shows one side of the switch connected to the neutral conductor. Although this conductor is not "live", it is part of the 110 volt circuit.

I would run a NMC or whatever method you are using and call it a day.

Would you re-identified the two red wires as signal wires though? Just to make it idiot proof for the owner.

 

[Andy Delle]

This is a similar issue in mini-splits. As an EE I would consider any control wire that is referenced to the line either by neutral or hot as a high voltage wire and handle it accordingly. Even if the wire is a low voltage signal line out of a microprocessor, if the circuit is line referenced, i.e., no isolation/power transformer, then that wire is electrically referenced to the line voltage.

An example of a true low voltage circuit is a conventional HVAC system with a 24v thermostat transformer. Here one side of the 24v may still be grounded but not referenced to the power line.

A couple of years ago I read some dirt cheap off-shore I-Phone adapters were flagged because the DC ground or negative was tied to the AC neutral. They were basic capacitor voltage dropping technology with no AC transformer (including a switch mode transformer). Now that's OK in many sealed appliances but not when the DC power is available to a user as an utility source.

 

[al hildenbrand]

Would you re-identified the two red wires as signal wires though? Just to make it idiot proof for the owner.

No matter how hard one tries to protect an idiot, a more incapable idiot will actually mess with it.

Seriously though, I like to twist the two NM "signal" conductors about each other for a couple turns, much like I code my threeway travelers in a switch box at rough in. Upon devicing, I will leave most of those turns in place for the next person to see.

 

[Nicksab]

No matter how hard one tries to protect an idiot, a more incapable idiot will actually mess with it.

Seriously though, I like to twist the two NM "signal" conductors about each other for a couple turns, much like I code my threeway travelers in a switch box at rough in. Upon devicing, I will leave most of those turns in place for the next person to see.

True. The twisting may do the trick. Faster than labeling it: "no power please or it is going to get really hot in here"