OH 3 Rules - Turn On Item For Said Peiord of Time

Setup, Configuration and Use Scripts & Rules
1

Hello!

I’m so happy to have gotten my rules finally working properly in OH3. Now to fine tune things…

Is it possible to turn on an item (switch) for a said period of time once a threshold has been met?

I’m looking to turn on a fan when a temperature trigger is set and leave the fan on for a period of time versus shutting the fan off when the temperature goes below that temperature trigger. Currently my fan relay is being tripped on and off constantly because my trigger point is teetering between units. I’m affraid I may have burned up my relay.

I’m getting so close to having a working controller. I do love the new OH3! :smiley:

Thanks!

2

Presumably this is because of another openHAB rule?

Have a look into the Expire functionality, which is now part of the metadata options.

3

So an example here would be the temperature set point is >=70 degrees. The temperature increases to 71 degrees. The fan kicks on and off until it goes to 70 degrees. If the fan would be triggered to run for 3 minutes time when the temperature was triggered, that would likely be enough time to resolve the issue.

4

What you are looking for is hysteresis. Design Pattern: Hysteresis

There is also a profile Items | openHAB so you might not even need a rule for this.

1 Like
5

I know this reply was from January but I just now got back onto the forum. Thank you so much for pointing out that I can set this item to Hysteresis. That’s huge!