The Grundfos UPM3 Solar 25-75 pump is manufactured in France and is designed for use in thermal solar systems. This model of the circulatory pump with a wet rotor is distinguished by 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), but it also allows operation in constant curve mode without the use of external control circuits. The rotational speed has 3 adjustable levels. The device’s housing is made of gray cast iron, housing a rotor made of stainless steel, supported by metal bearings. The device weighs only 1.9 kg. Only chemically inert and high-temperature resistant synthetic materials are used for the impeller, ensuring the cleanliness of the pumped liquid. This choice of materials and design allows for prolonged operation of the pump without degrading its technical characteristics or experiencing failures. The dimensions of the Grundfos UPM3 Solar 25-75 installation (length) are 130 mm. Both horizontal and vertical installations are permitted. 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 increase in temperature up to +130°C is acceptable.