Grundfos ALPHA Solar circulation pump, electronically controlled, PN 10, 130mm type 25-75

can be installed in all types of solar heating systems with variable or constant volume flow, but must not be controlled by an external speed controller that changes the supply voltage. The speed can be controlled by a pulse-width modulated signal (PWM signal) supplied by the solar system controller to optimize the solar energy yield and the system temperature. This significantly reduces the power consumption of the pump. If no PWM signal is available, the ALPHA SOLAR can be set to a constant speed. It is then only switched on and off by the controller. Technical data: Operating pressure: Maximum 1.0 MPa (10 bar) Minimum supply pressure: 0.05 MPa (0.5 bar) at 95 °C media temperature Maximum media temperature: 2 to 110 °C at 70 °C ambient temperature Degree of protection: IPX4D Motor protection: no external motor protection required Approval and marking: VDE, CE Water/propylene glycol mixture: the propylene glycol content in the water must not exceed 50% Note: when using a water/propylene glycol mixture, the flow rate is reduced due to the higher viscosity Product features: • 4 constant speeds • unlocking screw • PWM profile C (solar systems), the PWM signal is a method for generating an analog signal from a digital source • Low energy efficiency index (EEI = 0.20) • Maintenance-free • Quiet • Very easy to install