The Grundfos UPM3 Solar 25-75 pump is manufactured in France and is designed for use in thermal solar systems. This model of a wet rotor circulator pump stands out for its high energy efficiency and good performance, making it one of the best devices for operation in solar hot water systems. One of the main advantages of this model is the ability to connect external control devices with PWM (profile C), as well as the option to operate in a constant curve mode without using external control circuits. The rotation frequency has 3 adjustable levels. The device’s housing is made of gray cast iron, housing a stainless steel rotor that rests on metallographic bearings. The device itself weighs only 1.9 kg. Only chemically inert and high-temperature resistant synthetic materials were used to manufacture the impeller, ensuring the cleanliness of the pumped fluid. This choice of materials and design allows the pump to operate for extended periods without degrading its technical characteristics or experiencing failures. The dimensions of the Grundfos UPM3 Solar 25-75 installation (length) are 130 mm. It can be installed both horizontally and vertically. Threaded connections G1½” are used for system connection. To simplify installation and connection to electrical circuits, the supply package includes a power cable and a PWM control cable.
The Grundfos UPM3 Solar 25-75 provides a liquid pressure of 7.5 m with a flow rate of up to 3.4 m3/h. The power consumption is only from 2 to 45 W at a supply voltage of 220 50 Hz. The temperature of the pumped liquid should be within +2 to +110°C, but a short-term temperature increase to +130°C is permissible.