Multiple bath room switches.

Status
Not open for further replies.
480sparky

480sparky

Senior Member
Location
Iowegia
jeremysterling said:
As in the UK wiring "ring circuit" thread, there is an obvious debate here. Your design has merit as does the ring circuit.

I think the code intent is to avoid this type of install, as indicated by an exception that allows control wiring to be parallel with spelled out requirements. As with a "ring circuit", there is not absolute guidance on this install.

The OP can avoid this with his relays, because there is an exception for parallel conductors for control as long as the conductors meet the requirements of the exception in 310.4(A).
Click to expand...

The code's intent on parallel conductors is when more then one conductor is used to emulate a single conductor.


The NEC states parallel conductors as being joined together at both ends
(1) General. Aluminum, copper-clad aluminum, or copper
conductors, for each phase, polarity, neutral, or grounded circuit
shall be permitted to be connected in parallel (electrically
joined at both ends) only in sizes 1/0 AWG and larger where
installed in accordance with 310.10(H)(2) through (H)(6).
Click to expand...
My diagram has no such thing in it. There is not a pair of conductors that are teminated together at each end in this installation.
 
Last edited:
S

Speshulk

Senior Member
Location
NY
kwired said:
If you want to ensure the fan gets turned on, do you have a method that it much better? When the room is in use the fan is on. If you leave it up to the user to turn the fan on, some may turn it on, most probably will not.



Especially on a dwelling, why bother with all that extra equipment and expense - just put in individual fans for each room, it will cost less, and be simpler to maintain.
Click to expand...

If it's in a commercial / industrial application, then I'd consider putting it on a time clock that turns it on when the building is occupied. In the dorms I lived in in college, there were common remotely located fans that ran 24/7 with ducts run to all the bathrooms.

As far as the dwelling setup goes, I agree with you totally. But if you're gonna install a system with one fan and common ducting, then dampered lines will give you the best performance for the system.

One mistake I've seen a couple times that fails miserably is connecting two or more fans to the same duct. You end up blowing the moisture / odor from one bathroom into the others.
 
A

andyselec@aol.com

Member
Location
durham,nc
Occupation
Electrical contractor
S

stevenbouf

Member
Wow i didnt think i would have this many responses. There are four bathrooms. The venting and ducting is provided by hvac contractor. This is in a commercial space. Each bath room will have its own light with its own sensor. I guess im going to use four more sensors if back feedings not a problem to control the fan. Two pole sensors that mount to the ceiling would be great and im sure cheaper than eight of them. Im really surprised that there not made for large area where one sensor wouldnt cover the area.
 
Smart $

Smart $

Esteemed Member
Location
Ohio
stevenbouf said:
... Two pole sensors that mount to the ceiling would be great and im sure cheaper than eight of them.
Click to expand...
Well you will probably have sticker shock when you price them then... :p

Im really surprised that there not made for large area where one sensor wouldnt cover the area.
Click to expand...
AFAIK they do... but don't forget they don't "see" around corners or through partitions.
 
ptonsparky

ptonsparky

Tom
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
I would feed a CLICK or a PICO with an input from each lighting motion detector. Or a current switch monitoring each lighting circuit might be better if minor details are bothersome. Input from any turns the fan on. You could delay it off as well. Most likely need a relay on the output.

We recently used vacancy sensors in some restrooms. Light/fan had to be manually turned on but would shut themselves off if no motion detected after x amount of time.
 
kwired

kwired

Electron manager
Location
NE Nebraska
ptonsparky said:
I would feed a CLICK or a PICO with an input from each lighting motion detector. Or a current switch monitoring each lighting circuit might be better if minor details are bothersome. Input from any turns the fan on. You could delay it off as well. Most likely need a relay on the output.

We recently used vacancy sensors in some restrooms. Light/fan had to be manually turned on but would shut themselves off if no motion detected after x amount of time.
Click to expand...

I like the current monitoring idea. You could put all four bath lighting circuits on same circuit and monitor the main feed with just one monitoring relay to turn on the fan.
 
renosteinke

renosteinke

Senior Member
Location
NE Arkansas
What you xuggest can be done ... but might I suggest another approach?

There are a variety of switches available that have built-in timers. They are designed to let the fan run for a period after the light is switched off. They're marketed specifically for controlling bath fans.

You would wire these in parallel with your central fan.

The 'light switch' part you could put in series with an occupancy (not a motion) sensor.

Motion sensors are not good for bathrooms, as their view is too often blocked by stalls and partitions. Occupancy sensors can 'see around' such things.
 
Smart $

Smart $

Esteemed Member
Location
Ohio
renosteinke said:
...

Motion sensors are not good for bathrooms, as their view is too often blocked by stalls and partitions. Occupancy sensors can 'see around' such things.
Click to expand...
Generically speaking, the two terms are often used interchangeably, even by manufacturers. Check the sensing technology and coverage details before purchasing. If you want one that will "see" around corners and "through" partitions, go with ultrasonic. Infrared are line of sight only. Some utilize multiple technologies.
 
S

stevenbouf

Member
So I've looked around and came up with just occupancy sensor thats 24 volts and has its own aux relay with 2 poles. So one sensor in each bathroom one pole for lights and one for fan. All the fans contacts wired parallel. Levington makes them. Another problem I have is hvac RTU shut downs. The system is non addressible and the fire panel is hundreds of feet away through other units. I have a zone to use already how can I shut down these. I was thinking useing a relay on the horn circuit but when the alarm is turn off by the fire dept the relay would allow the rtu to start and they may still be operating. Know what I mean
 
kwired

kwired

Electron manager
Location
NE Nebraska
stevenbouf said:
So I've looked around and came up with just occupancy sensor thats 24 volts and has its own aux relay with 2 poles. So one sensor in each bathroom one pole for lights and one for fan. All the fans contacts wired parallel. Levington makes them. Another problem I have is hvac RTU shut downs. The system is non addressible and the fire panel is hundreds of feet away through other units. I have a zone to use already how can I shut down these. I was thinking useing a relay on the horn circuit but when the alarm is turn off by the fire dept the relay would allow the rtu to start and they may still be operating. Know what I mean
Click to expand...

I don't know what fire codes will say, but consider that most of the time the SOP for fire dept. is to turn off the power ASAP, so if they do that the fan will not restart if they turn off the horns
 
Smart $

Smart $

Esteemed Member
Location
Ohio
stevenbouf said:
... Another problem I have is hvac RTU shut downs. The system is non addressible and the fire panel is hundreds of feet away through other units. I have a zone to use already how can I shut down these. I was thinking useing a relay on the horn circuit but when the alarm is turn off by the fire dept the relay would allow the rtu to start and they may still be operating. Know what I mean
Click to expand...
In my experience with FAS's, which is quite limited, RTU's are shutdown through duct smoke detectors interlinked with the FACP and the RTU's.
 
S

stevenbouf

Member
kwired said:
I don't know what fire codes will say, but consider that most of the time the SOP for fire dept. is to turn off the power ASAP, so if they do that the fan will not restart if they turn off the horns
Click to expand...

Not sure i understand you. If i used the horn circuit. It would be like this, when the horns ring the 24 volts that drive the horns would also pull in a small relay coil that will open a set of contacts. The rtus have a 24 volt contact for emergency shutdown. That will work but when the fire department shuts the alarm off and theres still an emergency my relay will drop out and allow rtus to restart. I need a way to make this circuit have to be manual reset.
 
S

stevenbouf

Member
Smart $ said:
In my experience with FAS's, which is quite limited, RTU's are shutdown through duct smoke detectors interlinked with the FACP and the RTU's.
Click to expand...

I have never seen an rtu shut down with a duct smoke maybe if the system was addressible there was a relay in the rtu seeing the duct smoke would require a slc loop. This set up is not addressible and the fire panel is hundreds of feet away. Just looking for an altenative than running back too it.
 
S

stevenbouf

Member
kwired said:
I don't know what fire codes will say, but consider that most of the time the SOP for fire dept. is to turn off the power ASAP, so if they do that the fan will not restart if they turn off the horns
Click to expand...

Yes I guess. But if the fire was small maybe not im not sure if its ok to rely on the power being cut.
 
Status
Not open for further replies.
Top