The Grundfos UPM3 Solar 25-75 pump is manufactured in France and 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 the need for 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. The working wheel is made from chemically inert and high-temperature resistant synthetic materials, ensuring the purity of the pumped liquid. This choice of materials and design allows for prolonged operation of the pump without deterioration of its technical characteristics or failures. The dimensions of the Grundfos UPM3 Solar 25-75 installation (length) are 130 mm. Both horizontal and vertical installation is permitted. Threaded connections G1½” are used for system connection. To simplify installation and connection to electrical circuits, the supply 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 between +2 to +110°C, but short-term temperature increases up to +130°C are acceptable.