Occ sensor controlled exhaust fans - local disconnect

[clausb]

We have been specifying the wiring of the new style exhaust fans to be connected to the local receptacle or lighting circuit in bathrooms. With the old set up, you would control with the light switch or with a separate, dedicated wall switch. The new style fans run on low speed at all times when the bathroom is not occupied and then runs at full speed when occupancy is detected within the bathroom.

Question is, where do we put the local disconnect switch? We do not want to use a standard wall switch because that will cause the fan to not operate at the lower speed when no one is in the room and the switch is toggled off. The AHJ says we cannot use the cord/plug connection in the fan as a disconnecting means because it is not "readily accessible" without a ladder. I am considering a keyed switch, located behind the bathroom door or some other location where it is out of they way and labeling it as the exhaust fan local disconnecting means, but it just seems kind of goofy to me.

Has anyone had any experiences with this type of installation? Am I not seeing something that might be obvious to others?

Thanks for any help you can provide.

 

[iwire]

What size motor are we talking about?

What type of occupancy?

My first though is that the disconnecting means is not required to be "readily accessible" without a ladder.

 

[clausb]

The fan is 17W, it is a standard Panasonic Whisper Green ceiling fan for bathrooms. The occupancy is an apartment building.

The definition of "accessible, readily" states "Capable of being reached quickly for operation, renewal, or inspections without requiring those to whom ready access is requisite to climb over or remove obstacles or to resort to portable ladders, and so forth."

 

[don_resqcapt19]

I don't see a code section that requires a motor or appliance disconnec to be readily accessible. If this was an Article 440 application, that article uses the term readily accessible for the required disconnect, but adds that it be "readily accessible from the airconditioning or refrigerating equipment."

 

[hurk27]

I do not see where article 440 applies at all (see 440 definitions), this is a common household bath fan which is considered an appliance, and 422.31(A) clearly allows the breaker to serve as the means of disconnect I doubt that it is over 1/8hp or over 300 watts? and almost all of these have the required UL listed maintenance disconnect built in in the form of a plug and receptacle inside of the housing.

Has anyone been required to install another disconnect for a common bath fan??:?

 

[hurk27]

With the above being said, I have done exactly what you described in your OP, using a fan speed control mounted high on the wall near the fan with the OS mounted in the center of the room, using the dry contacts of the OS to shunt the fan speed control to high. back then I was wishing they made a OS that had this feature built in but all I could find was the bright and dim light control type that would not work for a motor.

Has anyone seen a occupancy sensor that will control a motor at a slow speed then go high when tripped?

 

[clausb]

Your comments triggered some brain cells causing the code to be on my mind and I broke down and did some code review on this last night.


430-102 is that the disconnect be in sight of the motor; it does not say readily accessible. Similarly, if we had a warehouse with an air handling unit hung from the structure, we would locate the disconnect high, with the equipment.

430-107 requires that at least one disconnecting means be readily accessible, and in my opinion, that is the circuit breaker in the panel.

430-109(B) tells us for motors 1/8 HP and less, the branch circuit overcurrent protective device can be used as the disconnecting means. (circuit breaker in the panel)

430-109 allows several types of disconnecting means, including the cord/plug (430-109(F)). We have the cord/plug inside the fan, from factory.

Hurk, check out the Panasonic Whisper greens. For building ventilation, in the super tight buildings we are supposed to be building now, we keep them on low speed 24/7 to keep a few CFM of air moving through the building and the occupancy sensor on the fan steps it up to high speed when it senses occupancy in the bathroom. If 24/7 operation is not acceptable, we sometimes install a time clock to run the low speed operation.

Thanks for your comments.