Replacing room sensor?

[dfd]

Hi there,

first, sorry for writing english, i do not understand swedish at all

I'm one of only a few Ulma PK 2000 owners in germany and i'm very satisfied with the performance.

Only i want to replace the room sensor (2-wire connection) with a more advanced one. A feature i want to have is at least a day/night program. Anybody have an idea what can be used for this? The only room sensors i found are relais based, which could not be used (?)

TIA, Frank

[Icecap]

If You want to "cheat" the sensor with a timer it could be done by having a resistor parallelled or in seria with the sensor, the exact connection depends upon what type of sensor it uses.

If it's a NTC a resistor parallell to the sensor will simulate a higher temperature and thus lower the real temperature.

If it's a PT100 or PT1000 the resistor needs to be placed in seria with the sensor to simulate higher temperature.

[dfd]

Nice idea, but i'm looking for a programmable solution - you know, we are all lazy , i.e.

mo - fri 07:00 - 17:00 18°C setpoint
mo - fri 17:00 - 22:00 21°C setpoint
mo - fri 22:00 - 05:00 15°C setpoint
...

I found a lot of room sensors / room temperature control, but all of them trigger output relais to on/off the pump (or so), not one do send analogue temperature to the sps.

[Icecap]

Now I don't follow...

I do get the idea of having a day-rythm but that will affect the whole house as it's the shunt that's regulated.

But You talk about roomsensor... It's not possible (afaik) to regulate only one room that way.

But anyway: to make a fake programmable sensor is possible but not easy at all! It will require a MCU and some circutry to fake the sensor and adjust to temperature and then while Your at it the same MCU could do the time-of-day adjustments.

But in my point of view thats the wrong way round to go, the programming should be done in the furnace, setting the target temperature. The complexity would be about the same and the result would be far better and stable.

Sure that feature is not available already?

[Torsten]

You need somekind of a PLC doing the job if u dont want to fill a box with homewired components.

AUTOMIX 30 Q
http://www.acaso.se/en/LK-Acaso/Product ... utomix-30/

[dfd]

Now I don't follow...

I do get the idea of having a day-rythm but that will affect the whole house as it's the shunt that's regulated.

That is exact what i want (and what i do currently manual every evening and morning).

But You talk about roomsensor... It's not possible (afaik) to regulate only one room that way.

The delivered and installed room sensor (in the living room, where the most constant temperature is needed) controls the SPS of the Ulma > pump and mixer, in fact the SPS regulates the heating flow (Vorlauf) and the pump pressure. The heating flow and the pump pressure should be lowered in the night. The individual temperature in the rooms are controlled in the rooms by the radiator thermostats.

But in my point of view thats the wrong way round to go, the programming should be done in the furnace, setting the target temperature. The complexity would be about the same and the result would be far better and stable.

Sure that feature is not available already?

Unfortunately there exist no such a functionality. So there is not an easy solution... What i found are programmable radiator thermostats. But they are expensive Anyway, i will research a bit longer. Thank you for your ideas.

Frank

[dfd]

You need somekind of a PLC doing the job if u dont want to fill a box with homewired components.

AUTOMIX 30 Q
http://www.acaso.se/en/LK-Acaso/Product ... utomix-30/

Thanks for the link, looks interesting. Will read the manuals there...

Frank