Grundfos CRN Flex

The Grundfos CR Flex is a high technology multi-stage centrifugal in-line non self priming surface pump specifically designed for water transfer, irrigation and pressure boosting in solar powered applications. It is fitted with the advanced MG Flex variable frequency driven motor that offers the following features:-

  • Runs at varying speeds depending upon the energy input available.
  • Can be used for DC or AC power supply and can therefore be connected to either PV solar modules, a standby AC generator or mains power supply as required.
  • Utilises Maximum Power Point Tracking (MPPT) technology that continuously optimises speed according to input power.
  • Built in protection for under and over voltage and system overload. No additional protection is therefore required.
  • One set of terminals included for either high or low level control functions.

Three models are available, all powered by the same 1730W motor providing a selection of head and flow outputs depending on application. System sizing is easy using the PC based Grundfos Product Center that optimises system design given the installation location, total head and water output required. 

Materials of construction is AISI316 stainless steel for the hydraulic components. 

The Grundfos CRN Flex renewable energy pumping system is efficient, reliable and cost effective and is the ideal solution for all off-grid water pumping applications. 

The pump is connected to an MG Flex 2 pole variable frequency drive (VFD) induction motor. The VFD controller is attached to the motor and can accommodate a wide voltage range. It also offers over and under voltage, overload and over temperature protection. 

Power Input: 60 - 1730W
Max Current: 8.9A
Voltage: 30-300VDC, 1x90 - 240VAC 50/60Hz
Motor Speed: 1000 - 3400rpm
Enclosure: IP54
Insulation Class: F

Options of the IO50 manual solar powered unit and the IO101 solar/generator flex unit are available. The IO101 controls supply to the pump from either source and automatically switches to solar power when the AC source is disconnected.

CRFlex should be powered by proprietary Photo Voltaic solar modules connected in arrays to provide the power required. Arrays should be connected in series to provide at least 110VDC to the motor

Pumped Liquid: Thin, clear, non-aggressive liquids not containing fibres or particles with a sand content of less than 20ppm.
Liquid Temperature Range: -20°C-+120°C
Max Ambient Temperature: +50°C
Max Input Pressure: 25Bar


Pump Dimensions (mm) Weight (kg)
B1 B1+B2 D1 D2
CRN Flex 3-11 423 657 122 158 34
CRN Flex 5-6 387 621 33
CRN Flex 10-2 373 607 49