Hi,

I first got the HIH-4021-003 from Digi key and accidently installed it backwards and it absolutely burnt up. Next I correctly installed an HIH-4000-002 from eBay and it to burnt up. Waiting for the second HIH-4021-003 from Digi Key to try but I can see the problem with the first sensor but the second one should have worked. Am I using the wrong sensors? I doubled checked the voltages from the Webcontrol8 and they look fine. Thanks for any thoughts.

Gary

I think I am finding that the pinout for the HIH-4021-003 is different than shown in the manual. I am seeing pin 1 as ground, pin 2 as out and pin 3 V.

Gary

Its been a while since I used the humidity sensor. Surprised it burned out even if you connected incorrectly. Check to make sure you have 5 volts between V+ and V- on the web board with nothing connected. . Here is link to the data sheet for this device. Spec says something about a 80 ohm load between Data and V-, i think this is allready on the web board, you check with a volt meter with no power to the board and see what you get. Those chips are expensive, I remember getting them for a few dollars. I checked but can npot find the spares i purchased.

Eric

https://static.datasheets.com/doc/13022347-honeywell-hih-4021-003-ds.pdf

Eric

I have checked the voltage and all is good there. If you install the sensor face up as in the diagram in the manual you would be putting + voltage on pin 1 and ground on pin 3. The datasheet for the HIH-4021-002 shows pin1 as ground and pin 3 as + voltage. So with my next one I will follow the stats for the HIH-4021-002. The second sensor I tried did overheat as I connected it as shown but quickly disconnect it from the board. I reversed polarity and it then did work without overheating but the readings are not accurate, I think the over heating caused internal damage. I have one more sensor coming so hopefully the third time will be the charm

Gary