This document defines the properties of Micropelt’s maintenance free, intelligent thermostatic head MLR003.
Installing the Micropelt MLR003 system is simple and only a matter of hours. Compared to conventional systems, the Micropelt MLR003 product allows significant cost savings on labour and material cost for wiring, network infrastructure, and building structural changes.
MLR003 is an 868MHz LoRaWAN CLASS-A wireless actuator. LoRaWAN allows to control over long distances, even inside buildings. LoRaWAN end-devices of Class A allow for bidirectional communications whereby each end-device’s uplink transmission is followed by two short downlink receive windows. The transmission slot scheduled by the end-device is based on its own communication needs with a small variation based on a random time basis (ALOHA-type of protocol). Class-A operation is the lowest power end-device system for applications that only require downlink communication from the server shortly after the end-device has sent an uplink transmission. Downlink communications from the server at any other time will have to wait until the next scheduled uplink.
Each standard production MLR003 unit has a unique DEVEUI, JOINEUI (APPEUI) and a randomly generated APPKEY. Device credentials are secret and will only be submitted with the product delivery. Questions related to device credentials can be sent to devicecredentials@micropelt.com.
To operate the device, the unit must be paired with a compatible controller or gateway unit supporting its communication profile. Once mounted and activated on the valve body using the magnetic key, a calibration cycle starts to automatically adapt itself to the individual valve. Then it is ready for use.
Success of activation or deactivation is signaled by tone signals and LED.
The product is delivered in mounting position (off) with the valve plunger completely retracted. When operating, the unit recognizes if it is installed on a valve body by means of internal force and travel distance measurement. The device has built-in motor error detection "ME". The ME bit signals motor issues during normal operation.
The actuator operates with a communication profile. Installation, activation and a successful join with the network server will immediately set the radio communication interval to every 10 seconds for an installation period of 5 minutes to provide rapid feedback.
The actuator has a built-in, valve-side temperature sensor to determine the flow pipe temperature. A controllable offset has been added to compensate for the temperature drop between the hot water and the sensor element located in the actuator’s aluminum valve adapter.
The integrated valve side temperature sensor is also used for freeze protection. Freeze protection is activated at ' aria-hidden='true'%3e %3cuse xlink:href='%23E1-MJMAIN-2264' x='156' y='-50'%3e%3c/use%3e %3c/g%3e %3c/svg%3e)
6°C.
The ambient sensor is used to measure the room temperature. During heating operation, the ambient sensor is influenced by self-heating of the metallic device housing. An algorithm is used to estimate the actual ambient temperature.
Temperature values are transmitted in both raw and corrected temperature formats.
If it has been 30 minutes or more since the device has received communication from the gateway (Join Request success, Downlink from user, ACK response), then the device requests an Acknowledgement of its next Uplink. An ACK request without an ACK response is reported by status bit “RCE”. After 3 consecutive unsuccessful ACK requests, the actuator automatically switches to “Rejoin”. In this situation, the actuator switches to Safety Mode and Safety Value as specified by the user, and sends Join Requests every hour until it rejoins a gateway.
The actuator generates the required electrical energy for operation by means of a built-in thermoelectric generator (TEG) and therefore operates maintenance-free.