
MVA004 User manual and device specification
2020 Page 5 of 25 1DSMVA004_0720v13e
4 System description
This document defines the properties of Micropelt’s battery free thermostatic radiator valve MVA004. The unit
is directly mounted onto radiator valve bodies (M30x1,5 thread), where it controls the room temperature, based
on signals of a central controller. It is radio-controlled and powered by energy harvesting, so it neither requires
any cabling work nor does it consume batteries. It is designed for maintenance-free operation. The wireless
design makes the unit ideal for retrofit installation and cost-sensitive projects, where cabling cost is prohibitive.
A room controller can be used to conveniently set time programs that set the room temperature to different
values at different times of the day. By lowering the room temperature in times of absence, heating costs can
be saved without any loss of comfort. Reducing the room temperature by just a few ° C also leads to cost
savings.
The actuator generates the energy required for operation (engine running, sensors and radio communication)
by means of a built-in thermoelectric generator (TEG) and is therefore maintenance-free. This is supplied from
the temperature difference between the radiator heat and the ambient temperature (usually the room
temperature). An additional source of energy, such as a battery or a mains connection is not required. The
internal energy storage is pre-charged upon delivery. This means that sufficient energy is available for the
installation and approximately one year of normal operation. The internal storage unit is recharged through
excess energy generated during heating operation, which means that sufficient energy is available for year-
round operation.
At its user interface, MVA004 has a red and a green LED, which are described in more detail in section 6. Two
internal temperature sensors are used with its internal temperature controller and freeze protection (ambient
sensor) and the automatic radio duty cycle control of 2, 5 or 10 minutes (flow temperature sensor).
MVA004 is operating with EnOcean standard EEP A5-20-01 (4BS) in either valve position or set temperature
mode. According to the standard protocol, the unit reports to the room controller every 2/5 or 10 minutes (auto
radio interval) transmitting its current valve position and status information. The room controller responds with
either a new control value in the value range 0% (valve closed) to 100% (valve maximum open) or setpoint
temperature (0 ... 40 ° C). When the setpoint changes, the actuator motor moves the motor to the new position.
When operating with the setpoint temperature, we recommend to use a separate, external room temperature
sensor that transmits its temperature to the room controller, which forwards it to the MVA004 as part of the
A5-20-01 protocol. By heat input from the radiator in the unit, there are deviations between the measured and
actual room temperature, which are compensated by means of an integrated correction function. The first 30
minutes after activation are used to calibrate the offset compensated ambient temperature value. During that
time, the valve will transmit its internal and fixed temperature value of 20°C and then automatically switch over
to the corrected value.
The actuator is delivered in mounting position (motor position is fully retracted). The actuator has an internal
valve recognition (ACO). In addition to a blockage, the ACO bit also signals any unsuccessfully completed
reference run and when starting from mounting position. A dynamic zero-point correction ensures that the
valve closes in the long term. Unmounted but activated will automatically move the motor back to mounting
position to switch-off the device.
In the event of a radio failure (6 unsuccessful communication attempts), the internal temperature controller is
activated, and the radiator is regulated to a preset 21 ° C. A change of the radio interval does not take place.
The drive goes into normal operation as soon as the radio communication is restored.
When operating in unheated rooms, the internal storage will eventually be discharged. The unit then moves to
50% open position to recharge its storage. Operation in unheated rooms is not recommended. If the operation
in unheated rooms cannot be avoided, the summer bit SB can be used. This means that the radio interval can
be extended to 8 hours and the drive can also be addressed via radio.
MVA004 is designed for low power operation. Therefore, all ReMan and ReCom operations are internally time
limited and must be executed within less than 8 seconds. It is strongly recommended to execute ReMan only
for initial teach over the air (Link Table) and device configuration (RESET) following its initial deployment.
MVA004 has a button lock after one-hour function integrated that will prevent from unintended use.