Motion Switch -> Exhaust Fan Issues - PLS HELP!!!


Old 02-11-10, 11:11 PM
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Question Motion Switch -> Exhaust Fan Issues - PLS HELP!!!

(new to forum - long post - pls read)

I am trying to install a motion detection switch(Leviton PR150 - 120VAC/60Hz/500W max incandescent 400VA max florescent) that will activate an incandescent light and 2 exhaust fans (Nutone Heat-A-VentLite(w/o nightlight) - 1500W fan-forced heat, 70 CFM exhaust fan and 100W max incandescent fixture and a Nutone 8" Vertical - 120VAC/60Hz/.8 Amp) (The heater is on its own circuit).

When the motion sensor is activated, the light comes on at about 95% capacity and the 2 fans BARELY move. However if I switch the motion switch to the manual override position, the light and fans all come on 100%. Just to be sure I replaced the motion switch with a single pole switch and everything worked just fine. I also tried putting in a different motion switch and even an outdoor motion sensor in the ceiling on a single pole "override" switch on the wall(thinking it might be "heavier-duty"). All 3 motion sensing devices gave me the same result.

I also tried just running one fan from the motion switch with the same result.

I inspected the crawl space of one of our campground restrooms that has an 8" fan on a motion sensor. I noticed that the Romex came from the fan ran into and out of a small, square, black box and continued on to the power source. From this black box, a pair of 16 AWG(or higher) ran down to the motion sensing device.

What is this black box and is it whats keeping me from running my fans on a motion switch?

Much Thanks in advance.
Old 02-12-10, 04:30 AM
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In your instruction sheet it says "To avoid overheating and possible damage to this device and other equipment, do not install to control a receptacle, a motor, or a transformer-operated appliance other than applicable fluorescent lighting.

When you use the bypass, it's just a normal switch.
Old 02-12-10, 04:38 AM
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It also sounds as if the campground fan/switch combo is controlled via low voltage relays, hence the smaller wiring and the "box". Not sure what the box is for. Doubling the number of fans makes the drawdown even worse. Hopefully the sensor switch hasn't fried yet, and you can still use it for lighting as designed.
Old 02-12-10, 07:35 AM
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It sounds like the black box is a low voltage relay that controls the restroom fan.

Could you point me in the direction of the appropriate relay and where I could purchase one. I tried googling it, but don't know exactly what I need.

Old 02-13-10, 10:18 AM
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does the fan(s) you are trying to run off the motion switch also have have the black boxes with the small gauge wires? if they do where is the sensor that controls it?

the black box is what we call a switch pack, it take high voltage ( 120 volts typically ), steps it down to 24DC to run motion / occupancy / infrared sensors, typically in the ceiling. typically there are 3 wires, blue, red and black going to the sensor. the sensor switches the switch pak ( a relay ) witch then closes the circuit for the load. the switch packs can also be bought for 277v if you got such voltage for lighting ( which is typical in commercial buildings )

how is the heater wired ( as in it's own switch??)

on a fan heat / light / exhaust combo, usually you have 1 - #12 feeding the heater element going to a separate switch ( usually a triple stack toggle ) and another 12-3 or 2 12-2s for the other switch loops ( or 14-3 / 2 14-3s with the exhaust fan neutral and light neutral tied together, but separate from the heater neutral )

you may want to check the Wattstoper RS-100, RS-150 or PW-200 or UW-200
as all are rated for fan loads, 1/6 hp max @ 120 volts
Old 02-13-10, 11:28 AM
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Mike thank you for your response. To answer your questions:

1. neither the fan nor the wall-mounted motion sensor came with the black relay box.

2. The heater is wired to its own switch and is on a dedicated circuit.

I found a Leviton power pack relay switch on their website that is designed for their ceiling motion sensing units that, like you indicated, has a black, red, and blue wire.

However, the wall-mounted unit does not have a blue wire (black, red, and green only) and they indicated that the power pack was only compatible with certain models (all ceiling units). : (

Is their a relay switch that is designed to work with the model wall switch that I have.

PS To add to my frustration, I was at the local hardware store this morning talking to one of the employees about my plight...I went to use the restroom, walked in and the light and fan both came on from a wall-mounted motion switch!! ARGGH!! I wanted to disassemble everything to see how it was wired. :/
Old 02-13-10, 01:29 PM
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There is couple items that need to be addressed one you do have low voltage switching there and second thing the motion switch you allready have there it will not work with fan motor useage.

I know there is better motion switch on market I used Pass & Syemour or Wattstopper one of two and few time other brands as well the key issue with low priced motion sensor like you stated that was NOT designed with motor load

Here is my soluation .,

Ditch that low voltage relay they will not work very well with motion sensor if you have ceiling mounted junction box then get ceiling mounted verison that will work far much better than wall mounted plus it will reduce the chance to get damaged as well due you mention campground.

you will have to keep the wall switch as master switch if you are serious about useing motion sensor fucntion then get the keyed switch I know they are not cheap but some big box store will have this otherwise best bet is electrial supply centre will have this on stock.

Here a gotcha senice you metion the heater is on own circuits you have to be extra carefull when you get the netural line up in fan / heater / light unit ditto with line side so if you have MC or AC cable the black conductor is used for light while the red is used for heater and netural for both.

If you have more question just ask us we will help ya more

I will find a way to make a drawing how this will work

Merci, Marc
Old 02-14-10, 10:55 AM
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power paks

the power pak is designed to be fed the incoming line frist and then low voltage cables run to your sensor location, which are typically ceiling mounted, which trigger the power pak relay and send the current through the fixture.

though they do make 24 volt wall switches designed to go with the power paks

the bathroom you mention probably had a wattstopper line voltage wall switch line voltage, ( unless you saw a ceiling sensor then it's a 24 volt model ) as it common for commercial applications

the leviton switch you have was not designed to use a power pack since it only has line voltage input / output, i agree with Marc, ditch the power paks and get a good wattstopper. though as you see it good for 1/6 hp total, i do not know how amps both fans draw, though the dual relay model may be your best bet since you are running 2 fans

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