Electrical – Bathroom Fan with Humidity Sensor Wiring Question

bathroomelectricalwiring

I just purchased a new fan for a bathroom with an in-fan humidity sensor. Here's the installation manual.

The fan has 6 wires coming out of it: 2 black, 2 white, 1 brown, and ground; the brown is labeled 'for humidity sensor or speed control'. Am I going crazy or does the wiring diagram on p.3 of the manual suggest that you need two switches for this: one for the fan and one for the humidity sensor? This seems a weird set up because I can see my kids repeatedly flipping the useless switch that apparently does nothing (i.e., the humidity sensor switch!) to get the thing to work. Two questions:

  • Any ideas on whether this must be wired with two switched?
  • If not, do you think everything could be wired to one switch and everything still work?

I've tried contacting the manufacturer and it seems that customer support is non-existent smh…

Thanks in advance.

Best Answer

Presumably the fan and humidity sensor can be switched independently to give you a choice of operational modes. Switching on the humidity sensor gives it control of fan cycle. Switching on the fan directly overrides that mode.

The humidity control and fan can be operated separately. Use a 1- or 2- function wall control. Do not use a dimmer switch to operate the humidity control.

You can connect the brown to a switch or you can connect it directly to the hot conductor to have the humidity sensor operate full-time. It doesn't really matter as long as both blacks and the brown from the fan unit have power when you want it to run.

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