Energy Harvesting

The actuator obtains the electrical energy required for operation by means of a thermoelectric generator (TEG), from the temperature difference between the heating flow temperature and the room temperature. During active flow temperatures, excess energy is accumulated in the internal storage. The energy balance of the actuator is designed to allow operation through 366 days per year when used in typical circulation strands with hot water supply throughout the year. A lack of hot water operation as it occurs in down times or malfunctions inevitably leads to the internal storage being discharged, which means that permanent and normal operation of the device can no longer be guaranteed.

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Device power management

 MLR003FiEU61-12-1.1 allows the end user application to monitor and compute the energy status through regular measurement of the device internal parameters. Internal storage voltage STV (V) and average current generated ACG (µA) are actual measured values whereas average current consumed ACC (µA) is a computed value. The computed average current consumed value includes motor amount and direction of movement, radio communication frequency, and sleep current. The following two diagrams are illustrations of the energy balance from a running application.

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Energy Storage

Using its status bit "Energy Storage", the unit indicates that its long-term operation consumed more energy than it generated. The remaining charge level at this point is approximately 25%, which is why the device continues with full functionality while signaling a negative energy balance to the user. It is strongly recommended to regularly check the ES bit in order to recognize a discharge of the storage and to prevent its progression by suitable measures (e.g. regular, short heating intervals outside of the standard operating times). If the energy storage continues to discharge and its voltage falls below a certain limit, then the unit automatically goes into the state of forced heating. 

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