Panasonic FV-MSVK1 WhisperGreen Select SmartAction Module, Automatic Motion Sensor, 20 Minute Timer

Shipping was slow, but excellent customer service.

I bought this motion detector switch NOT to turn the fan ON, but to turn it OFF AFTER A DELAY period where it ran for 20 minutes or so. I could have done the same thing with a timer switch, but I have recently upgraded outlets and switches to the fancy and pricey ADORNE style, where timer switches are $50+ not including the wall plate. The Panasonic motion sensor "saw" the doorway a little too well and was turning on when the dog walked past, so I placed a sliver of aluminum foil over an edge of the sensor but UNDER the lens cover so the foil wouldn't show, to cut down the sensor's field of view a little. Works fine. I timed it once and it turned off after just about exactly 20 minutes. When you install, be sure to plug it into the correct block (there are three).

With our old bathroom fan, I always found myself going behind our children turning the fan off because they forgot. Never again! I have the Panasonic fan set to run for 30 minutes motion activated using this module. Works great!

This functions as promised and turns on the fan for about 10 mins when it senses motion. We first tried the shower humidity detecting plug-in, but it just didn’t work.

The instructions for the motion detector and fan don't help very much with understanding how this thing integrates, so consider this your instruction addendum. Once it was wired into my Panasonic Whispergreen fan, the signal switch turned into a motion detector switch. The photo above of my switch labels probably explains best: One position for the signal switch makes the fan run continuously, and the other position of the signal switch makes it only operate for 20 minutes after detecting motion. The fan switch must be on; if it is off then the fan is always off. The motion detector goes into the knockout in the grille that says "select", as you can see in the picture. Strangely it will only fit in with the wire heading out toward the edge of the grille. Also strangely, I had a lot of difficulty plugging in the connector to the fan; I suppose some lint was blocking it because I got it in easily after dusting the area completely. The takeaway is that installing the motion detector does not eliminate the option of running the fan continuously when needed, which was completely unclear from the instructions. Overall, worthwhile upgrade. It does what it says it will.