Theoretical
Let's wire the Havaxer 02 to become a complete HVAC controller handling two heating/cooling circuits.
- Connect the outside temperature sensor to TEMP1.
- Connect the domestic hot water (DHW) temperature sensor to TEMP2.
- Connect the system supply or buffer top temperature sensor to TEMP3.
- Connect the circuit 1 supply temperature sensor to TEMP4.
- Connect the circuit 2 supply temperature sensor to TEMP5.
- Connect the circuit 1 mixer to TRIAC1 and TRIAC2.
- Connect the circuit 2 mixer to TRIAC3 and TRIAC4.
- Connect the circuit 1 pump to RELAY1.
- Connect the circuit 2 pump to RELAY2.
- Connect the heat source controller to RELAY3. When the RELAY3 is on, the heat source should start heating the supply water.
- Connect the DHW changeover valve to RELAY4. And the DHW charge pump if not provided by the heat source.
By creating a logic bridge between all these connections in an application, the program might do something like this:
- Monitor the TEMP2. When drops below 42° C, turn the RELAY3 and RELAY4 on. When climbs above 48° C, turn the RELAY3 and RELAY4 off.
- If circuit 1 is enabled, turn on the RELAY1. If not, turn the RELAY1 off, TRIAC1 off and TRIAC2 on (closing the mixer).
- If circuit 1 is enabled, monitor the TEMP4. When drops below 26° C, turn the TRIAC1 on for 3 seconds. When climbs above 28° C, turn the TRIAC2 on for 3 seconds. Repeat after 15 seconds.
- If circuit 2 is enabled, turn on the RELAY2. If not, turn the RELAY2, TRIAC3 off and TRIAC4 on (closing the mixer).
- If circuit 2 is enabled, monitor the TEMP5. When drops below 34° C, turn the TRIAC3 on for 3 seconds. When climbs above 38° C, turn the TRIAC4 on for 3 seconds. Repeat after 15 seconds.
- Monitor the TEMP3. If it drops below the minimum required supply temperature of each enabled circuit, turn the RELAY3 on. Turn it off when the TEMP3 reaches that temperature plus 7 K or after 60 minutes.
- Monitor the TEMP1 and adjust the circuit 1 and 2 required supply temperatures.
The temperatures and times here are for example only.
There is still TEMP6 available. You can use it to monitor one room temperature, for example.
Additionally, the SIG1 and SIG2 can turn off-board relays on and off directly, for example a relay for a DHW circulation pump.
By connecting a standard electrical light switch to OC1, you can read a user demand for extra hot water, for example.