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 is distinguished by its high energy efficiency and excellent 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 can also 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, which houses a stainless steel rotor supported by metallographic bearings. The device weighs only 1.9 kg. The working wheel is made from chemically inert and high-temperature resistant synthetic materials, ensuring the purity of the fluid being pumped. This choice of materials and design allows the pump to operate for a long time 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 installation are permitted. The system connection uses G1½” threaded connections. 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 between 2 to 45 W at a supply voltage of 220 50 Hz. The temperature of the fluid being pumped should be between +2 to +110°C, but a short-term increase in temperature up to +130°C is permissible.