toilet room exhaust fan

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Mike01

Mike01

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just curious I saw a set of plans that called for one fan for two toilet rooms but the fan was to turn on / off from either toilet room? how is this wired can it be done? if the fan is already running and someone else enters the adjacent toilet room and turns the switch on the fan is already engerized, then could you potentally have 240V at the fan only rated for 120V or do you use the same phase so that it only sees 120V? I don't know maybe I am thinking about this to hard Just curious as I have never seen an installation like this. Thanks.
 
Three way switches are the obvious but we often don't do that because the fan is a remote fan and you cannot hear if it is on or off. We usually have 2 sp switches with timers. If the first person's timer goes off then the fan goes off unless the second timer is activated.

Run your feed to the fan and drop 2 wires down to each switch.
 
Mike01 said:
just curious I saw a set of plans that called for one fan for two toilet rooms but the fan was to turn on / off from either toilet room? how is this wired can it be done? if the fan is already running and someone else enters the adjacent toilet room and turns the switch on the fan is already engerized, then could you potentally have 240V at the fan only rated for 120V or do you use the same phase so that it only sees 120V?
Click to expand...

We just use standard single pole switches wired in parallel supplied of course from the same circuit.

Supplying it from another circuit even of the same phase would be a violation of at least 240.8 and while supplying the correct voltage the available current would be double.
 
hmm..

hmm..

No the lighting circuit and the fan circuit are two independant 120V circuits originating from the same panel, it sound to me
We just use standard single pole switches wired in parallel supplied of course from the same circuit.
Click to expand...
sounds like the best and most economical way to go I am going to try to work this out on paper real quick and see if i can make this work because i am still not sure how they will wire it or the correct way to indicate it on the plans. thanks.
 
I use alot of remote in line fans in residential, so using 1 fan for more than 1 bath is pretty common, Like said before just feed the fan and run switch legs down to the bathrooms,

I've had bathrooms with fans and lights to come on together, in this case I use a relay so the other bath lights do not come on...
 
How about just using ice cube relays?
That way you won't have any voltage from one restroom backfeeding to the other.
Using a two pole switch in each restroom would seem like you could be arranging a dangerous situation if someone was replacing a switch in one room and someone turned on the switch in the other.
 
dezwitinc said:
Using a two pole switch in each restroom would seem like you could be arranging a dangerous situation if someone was replacing a switch in one room and someone turned on the switch in the other.
Click to expand...

Why would one be swapping out devices "hot"?
 
Just to state something that might be obvious, you do need the double pole switches (or ice cube relays) if you also want each switch to control a light fixture in each toilet room.

Steve
 
yep

yep

Just from looking at the prints this is all that I saw: a switch in each toilet room, and associated lighting for each, each toilet room has a switch with a note indicating the exhaust fan to be interlocked to the light switch in both toilet rooms so no matter what toilet room is being utilized the fan and associated lights are energized and I understand these need to be on the same circuit, with a two pole switch at each location but how exactly is this wired this is more of a question out of curiously instead of saying yeah ok, I like to understand what I am looking at and am just having a hard time visualizing this one.
 
Set a junction box with only one circuit running in to it. Drop one cable to each switch from that box. One constant hot and one switch leg in each cable. Tie the two constant hots to that circuit. Run one cable to your fan from the junction box. Tie the two switch legs to the cable feeding your fan. The fan will not shut off until the two switches are off at the same time.
 
If you are using a two pole switch rated at 240 volts you can then use two circuits. One to feed the fan and one for the lights. Or you can feed the other side with the same circuit using a pigtail to feed each side of the switch at the switch box. You will then have to use a 4 wire cable running to each switch so that you can have two switch legs from each switch. With out using the ground to feed anything. One for the lights and one for the fan. You will still tie the two switch legs for the fan to the feeder of the fan.
 
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wow

wow

Wow thats some crazy #%^& (in a good way) I am going to try to draw this out. thanks kda3310 for the explanations.
 
Mike01 said:
Just from looking at the prints this is all that I saw: a switch in each toilet room, and associated lighting for each, each toilet room has a switch with a note indicating the exhaust fan to be interlocked to the light switch in both toilet rooms so no matter what toilet room is being utilized the fan and associated lights are energized a
Click to expand...

Your going to need a relay, or else the other bath lights are going to come on whenever a switch is in the on position...
 
Not if he is using a two pole switch in each room. One side of the switch will be for the lights and the other side will be for the fan. You only tie in the two switch legs for the fans together. The switch legs for the lights goes to the light in each room.
 
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kda3310 said:
Not if he is using a two pole switch in each room. One side of the switch will be for the lights and the other side will be for the fan. You only tie in the two switch legs for the fans together. The switch legs for the lights goes to the light in each room.
Click to expand...


Lets see you install a dimmer with that setup... :grin:
 
Let's try a simple visual:

bathfans.jpg
 
480sparky said:
Let's try a simple visual:

bathfans.jpg
Click to expand...
Simple enough, and I like the idea of everything being on the same circuit. The all-circuits-feeding-one-yoke handle-tied-disconnect rules may not apply to this set-up, but it's a darn good idea.
 
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