UV temperature cutoff

[BeanAnimal]

A bit of frustration here.
As far as I can tell, there is no way to setup temperature thresholds for switches or logic other than using virtual probes.
If I am missing something, I think that this is a huge shortcoming.

I want my UV to turn off when the tank hits 79.5 degrees.
I don't want it to turn back on until the tank cools off to 77.5 degrees.
This histeresys is to prevent it from A) continuing to heat the tank and B) to prevent short cycling damaging the bulb with dozens of unseeded starts.

I set a virtual probe and set the nominal to 79.5 degrees.
I have set the UV switch channel to "heater" (again a shortcoming in interface naming unless I am missing something).
From what I gather from the manual "Heater" = "Up Regulation" mode.

So I would think that when the temperature reaches 79.5 degrees then the switch should turn off. IT DOES NOT. It turns off at some value (not caught it) above 79.5.
Hysteresis should not come into play until the temperature falls below the hysteresis set point and turns the switch back on.

Secondly - why is the Hysteresis "half of the hysteresis set point" - that makes no sense to me and gives the impression that it alters both sides of the set point.
If Hysteresis is only "up regulation" or "down regulation" (Heating or cooling) then it should be the set number, not half of it. Unless I am missing a combined heating/cooling mode around a single set point.

I tried everything under the sun with hysteresis and I can't get it to work as expected.
In this case the switch should be OFF but it is still ON
It should be off and stay off until ~78.75

EDIT: The switch turned off and 79.9 even though nominal is set to 79.5


Anybody?

 

[Lasse]

Setpoint 78,5 degrees - hysteresis 2 and Heating will solve the problem

The hysteresis works that way that if you set it to x - the working range is -X/2 to + X/2 around the nominal value

Sincerely Lasse

 

[BeanAnimal]

The switch finally swiot

Setpoint 78,5 degrees - hysteresis 2 and Heating will solve the problem

The hysteresis works that way that if you set it to x - the working range is -X/2 to + X/2 around the nominal value

Sincerely Lasse

Thank you for the response.

I understand what you are saying, but that is not the way hysteresis should work and not the way it is explained in the manual.

Heating Mode = Up Regulation
At any point below the set point the switch should be ON (heating the tank).
Once the EXACT set point is hit the switch turns OFF
As the tank cools, the switch stays OFF until the hysteresis point is met.

Cooling Mode = Down Regulation
At any point above the set point the switch should be ON (running the cooler)
Once the EXACT set point is hit the switch turns OFF
As the tank heats, the switch stays OFF until the hysteresis point is met.

Heating and Cooling mode are separate one or the other is chosen in settings.

If there was a "heating and cooling" mode then "nominal value" would be +/- 1/2 the hysteresis value.

@Gaël can you add some context here?

 

[BeanAnimal]

@Gaël or @Vinny@GHLUSA can you take a look here?