solar water heating

Solar thermal systems for heating water can be easily controlled directly by the Foxtrot system. No autonomous regulation is necessary; you can use directly the temperature sensors (collector, tank) connected to the analogue inputs of the Foxtrot system; the circulation pump is controlled directly by Foxtrot, and valves can also be controlled.

Selecting and connecting temperature sensors described in temperature measurement articles. During the selection you must take into account the thermal requirements on the collector temperature sensor and the correct placement of the temperature sensor in accordance with the specifications of collector manufacturers. For measuring the temperature in the storage tank, it is possible to use a common design of cable sensors, or sensors with a stem (as a standard, the tanks are equipped with immersion sleeves).

The circulation pump can be switched either by a standard relay output, or semiconductor outputs DO1 and DO2 can be utilized, which are equipped with the Foxtrot basic modules CP-10x6 and 10x8-CP; they allow a certain extent of control of the circulation pumps speed - see figure below.

For the control itself you can use the FB in Mosaic environment, or in the case of a specific installation (several tanks, heating, etc.) the application can be programmed as needed. The system can also be supplemented by measuring the gained heat.

         
Fig. 1 Example of connecting a circulation pump to the basic module CP-1016

Note:

1. The figure shows the connection of up to two pumps with an asynchronous motor with the possibility of speed control (max. Pump input approx. 140 W).

2. The temperature sensors shown in the diagram are connected to the analog inputs of the CP-1016 module or any CFox module with suitable inputs for temperature measurement.