Hopefully someone at CAI Networks can help with this mystery. I've used WebControl 8's for several projects, including the HIH-4000 humidity sensor. My current project is an outdoor temperature/humidity data logger. But when I tested this one and mounted the HIH-4000 directly to the WebControl8 terminal strip, per the picture, it blew it up. https://sensing.honeywell.com/honeywell-sensing-hih4000-series-product-sheet-009017-5-en.pdf Looking at the HIH-4000 data sheet Vcc/ground are opposite of how the WebControl8 manual says to connect it. What baffles me is I've used several of these humidity sensors in the past connected per the user manual and they work fine. I looked at old WebControl and HIH-4000 data sheets and they have always used the same pinnouts of both the board and the part. This is a $15 dollar part so I'm hesitant buying another one and connecting it in reverse to see what happens. If the documentation is incorrect - why have the senors worked in the past?