Illustrated below is a control box under control of the "Impulse 112.4" controller. It includes 2 temperature sensors (for temperature measurement in the ventilation duct and at a point in the ventilated room), 2 combined temperature / relative humidity sensors (to measure outside and inside the ventilated room), relay control module with 8 relays, one double-line HMI LCD operator panel and one integration unit for electricity meters via the protocol DLMS / COSEM.
The functionality of the control box for the freecooling installation allows to perform automated control over the operation of supply and exhaust fans, position valves to control the temperature of air in the mixing channel.
The control box has two electricity meters Nick 2303. The first utility meter measures consumption of air conditioners in the technical room. The second meter has the fans of the freecooling system and the control box itself connected under it. This allows to carry out real time measurement of consumed power. The utility meters are connected using the DLMS/COSEM communication protocol via a physical RS485 bus.
Through the HMI operator panel an administrator can adjust the settings for the freecooling system and view the current real-time measurements and parameters.
The ease of use of the system is provided by that the system parameters can be set in relation to the measurement counters from the utility meters along with the criteria of internal / external temperature or humidity.
If the freecooling system must be turned off, for this purpose there is a button on the front of the box that switches the mode of operation between "freecooling / air conditioning" and "air conditioners only".
For emergencies such as fire alarms or other possible technical failures related to the ventilation, there are red indicators on the front of the control box.
For remote monitoring and viewing of statistics, the controller "Impulse 112.4" transmits the statistical parameters to the centralized control system over an IPv4 network. The transmitted data packets are in XML the format indicating the type of data transmitted and the time of the parameter change.