The actual power of a heat generator is the total power of the active stages.
The spare power of a heat generator is the power of the inactive stage(s). E.g. the spare power of a two staged boiler working only in stage 1 is the power of stage 2. The spare power of a 2 staged boiler where both stages are active is equal to “0”.
Every heat generator calculates its own actual, spare and last switched power and adds it to the respective values it receives at the global register inputs. Finally the heating control strategy receives the total powers and also takes care of resetting the values again.
The actual, spare and last switched powers of all the active heat generators will be transmitted between heat generators and strategy via the internal registers.