Several control modes
Constant pressure
MIDA controls the pump speed to maintain constant pressure at a set point independent of the water demand in the system.
Constant differential pressure
MIDA performs the operation at constant differential pressure by using a differential pressure sensor or using 2 pressure sensors installed in the suction and delivery sides of the pump. Difference value is calculated by the MIDA itself from the two values read.
Constant pressure: 2 set-points
By selecting the constant pressure 2 values control mode, in irrigation systems, only one pump can serve two zones with different pressure sets. It is possible to switch the two values by acting on a digit input contact.
Constant temperature
The control method at constant temperature is used to maintain the temperature of the pumped fluid to vary the thermal load. This control system is used in air conditioning or refrigeration and cooling towers. In this latter case, for example, the temperature measured by a sensor in the return water is kept constant.
Constant flow
By selecting the constant flow control mode and using a flow transducer , it is possible to control the flow of the pumped liquid to vary the system condition. This control mode is used, for example, in a system for filtering the pumped fluid in which the obstruction of the filter would lead to a progressive reduction of the flow rate if it is not compensated by an increasing of the pump speed.
External frequency
In some application, it is chosen to change the frequency of the pump by using an external signal coming from a trimmer or a PLC. In this case, after selecting the External Frequency control mode, it is enough to connect an input signal 4-20 mA or 0-10V, proportional to the desired frequency, to the AN4 analogue contact.
