Mach929

iTrader: (3)

i got a new bath fan, here's how they want it installed:
http://www.broan.com/ImageLibrary/br...s/99044368.pdf

can i do it this way?
i want the fan to come on with the light switch, but i also want the humidity sensing switch to operate indepedently, can i do this?

magnamx-5

iTrader: (7)

Um assuming the black is ground where is your hot comming in?
Or is that the new circuit you put in? If the unit you show there has a relayed ground system that gets its source from the switch on the wall or the humidity sensor then you are ok.

Mach929

iTrader: (3)

black is hot in ac, trouble is a house doesn't work like a car so i have to unlearn stuff

both circuits have a hot, one leading to the switched on the other giving constant power for the humidity sensor, at least that's how it's working in my mind. will it be a problem if the switch is on and the humidity sensor is tripped at the same time?

magnamx-5

iTrader: (7)

nah it works like a car except you have the black is hot and the cold wich is whatever collor you have and the ground with until like the mid 90's was a flybynight option. And realy came into play when flourescent bulbs etc are put into play. But the electricity is still the same hot a cold with a ground for safety as it where to disipate any roque energy. And instead of grounding to your frame or block etc your negative needs to go back to the box this means that the picture you show lacks a negative lead going into the system and will not work.
Unless the new circiut is fresh wire etc you pulled to the box and the hot feed off the light switch goes into a relay to engage the internal mechanism of the fan.

Joe Perez

iTrader: (8)

We'll all be killed...

For residential work in the US, the following standards apply:

White is always neutral.

Black is always hot. In a three-phase (208/230) environment, red and blue are also hot. (480/277 3-phase circuits use a brown-yellow-orange scheme)

In single-phase 110/220 applications where both hot legs are present in a circuit, one is always black, the other is almost always red. In such an environment, the potential between white and black or white and red is 110v, the potential between black & red is 220v.

In single-phase applications where two or more unique hot wires are present in a circuit (such as on a three-way switch or a multi-gang switch) they are typically coded 1-black, 2-red, 3-blue, 4-yellow... It is both permissible and not uncommon for other colors to be used for additional hot legs, so long as they are not white or green.

For a 220v appliance where no neutral is needed, standard white/black/gnd romex is often used, with the white wire carrying the second hot leg in lieu of a red wire. The white wire must be clearly marked at both ends to indicate this use, usually with a few turns on black or red electrical tape.

Ground may be uninsulated when in romex or NMT, but must be jacketed in green or green/yellow if in a metallic carrier.
black and red.

(Note that this refers only to premise wiring.)




Now, check out Wiring Option #2 in the documentation:



The "Model 68W" switch they refer to is a non-interlocking two circuit switch. Here's the documentation on it: http://www.plumbersurplus.com/pdf/99043739.pdf

So, wiring it the way you propose is essentially the same as if you wired it as per Option #2 and simply left the lower switch "on" all the time.

Braineack

iTrader: (62)

Yep just need that switch. So the Common (white) and GRD (copper) get wired directly to the unit, the 110v (black) goes into the switch then out to the BRN and ORG on the unit. It's essentially the same wiring as #1 but you spitting the power at the switch and giving the unit it's magical constant power.

Joe Perez

iTrader: (8)

Incidentally, if you take a moment to register here, you can access the complete, unabridged 2008 NEC for free.

Mach929

iTrader: (3)

joe is there anything you're not an expert on?

anyhow, i'm a little confused. What do you mean by the lower switch on all the time?

are you saying that the way i have it drawn up will only activate with the lower switch on?

what i really want is that the fan will come on when the switch is on, because if someone takes a nasty **** i want it to expel the stench. I also want the humidity sensor portion of the fan to be able to operate the fan when the light switch is turned off, because i like to get a shower in the morning with the light off. Also with this fan, when the humidity sensor activates the fan it will stay running for an additional 20 minutes to make sure it gets rid of most of the moisture. that way i can leave the bathroom, get dressed and leave for work without leaving the bathroom light on all day.

Mach929

iTrader: (3)

i don't want to change out my switch because it's got one switch for the the light and an outlet for my wifes appliances.

Braineack

iTrader: (62)

look at my post again, I included a picture of the switch.

basically the power is going into the switch and splitting. The ORG should always be powered for the auto function, and the top will manually control the fan when you want it.

Braineack

iTrader: (62)

Then you could just run that constant power line from any other source (like the outlet), but you'd have to run the damn line up the wall...

Joe Perez

iTrader: (8)

Love.



In the diagram provided with the fan, in "Option #2" they depict a model 68W switch. I provided a link to the documentation for that switch, and Brainey posted a picture of it.

The 68W is just two switches in one housing, an upper and a lower, which share a common input and have two separate outputs.

In "Option #2", the upper switch is connected to the orange wire at the fan, and thus controls the manual on/off function. The lower switch is connected to the brown wire at the fan, and controls the automatic function.

In looking at what I just wrote, I realize I mis-typed, and I believe your diagram may be backwards. It looks like you want to tie the brown wire directly to the incoming hot leg, and put the switch on the orange wire. This should be equivalent to leaving the lower switch turned on all the time in "Option #2".

Ben

iTrader: (33)

You can always rip that out and put in a double gang box with a dual switch on one side and a proper GFI outlet on the other. That's what I'd do.

I've also seen a decora style single gang dual switch that was a combination light dimmer and fan timer at home depot. Kinda pricey, but I like dimmers.

<edit>
Or you can replace your existing switch/outlet combo with a dual switch combo, and then towards the center of the stud bay simply install a GFI in a retro box. No sheetrock work required that way.

Mach929

iTrader: (3)

****, i feel like an idiot over here. getting more confused
you guys are suggesting new switches. can this be done with my existing normal, single on/off switch?

Braineack

iTrader: (62)

well if you have the means to provide the black to the unit through a constant supply and a second through your switch like you have drawn, then yes that will work.

Ben

iTrader: (33)

Sure it can. But consider this.

Replace your existing single gang combination switch/outlet with this combination light dimmer/fan timer





Then a few inches from the switch location, install a retro box with a GFI outlet. You will have to run a small lead of romex from the swtich location to the outlet location.





You can also put the switch and outlet side by side in a double gang box, but it will require a little sheetrock finishing work.

Joe Perez

iTrader: (8)

Yes. You can do it exactly like you drew in post #1, but flip the orange and brown wires.


The documentation for the unit states that it is not to be used with a dimmer / speed control.


From what I gather in all this, the big holdup is needing to work with an existing wire in the wall which is currently supplying an incandescent fixture, and not wanting to run additional wiring from the j-box up to the fixture. I can sympathize with this. Assuming that an unswitched hot wire is available in the location where you want to put the fan, all is well.

Mach929

iTrader: (3)

thanks scott, do you also agree with switching brown and orange? either way it's an easy switch back and i can't really see any harm.

Ben i'll trying to keep costs and work to a minumum, since it's also a little daunting for me to also have to cut a hole in my roof.

exactly joe, i have a new junction box i installed when i put ceiling fans in, it's directly over where i'll be putting the fan.

anyway you guys are the best!

and joe i'll make you an expert on love, are you allergic to latex?

Braineack

iTrader: (62)

yeah, the constant black wire should go the BRN and the switched black wire to ORG.

Look at Option #2 in the pdf, when power goes to the BRN wire, it's using the Humidity Controls, the red to orange is labeled as fan on/off.

Ben

iTrader: (33)

A timer is not a speed control.

Dude if you get a standard type single gang combo switch, single gang retro box, and a GFI outlet (you'll already have romex), you'll spend about $20. The most expensive part by far is the GFI outlet. You'll then at any time be able to run dimmers or timers. I don't understand how people don't have dimmers on bathroom lights personally.

Upside:
You have independent fan and light control so the bathroom does not feel like a motel, plus your power outlet will be GFI protected.