SQFlex system
The SQFlex system is a reliable water supply system based on renewable energy sources, such as solar and wind energy. The SQFlex system incorporates an SQF submersible pump.
Very flexible as to its energy supply and performance, the SQFlex system can be combined and adapted to any need according to the conditions of the installation site.
The system components are:
• SQF submersible pump
• CU 200 SQFlex control unit
• CIU 903 SQFlex control unit (option for remote monitoring)
• IO 50 SQFlex switch box
• IO 101/IO 101 B SQFlex switch box
• charge controller
• energy supply system:
- solar panels
- wind turbine
- generator
- batteries
Pump
The SQF pump range comprises two pump technologies:
• helical rotor pump (3'') for high heads and small flow rates
• centrifugal pump (3'' and 4'') for low heads and large flow rates.
The performance curves below illustrate the pump performance of the two pump models.
Motor
The motor has been developed specifically for the SQFlex system and is designed according to the permanentmagnet principle with built-in electronic unit.
The SQFlex 3'' motor range comprises different motor sizes, the MSF 3 with 4 different maximum power input (P1) ratings of 300 W, 900W, 1400 W and 2500 W.
The motor speed range is 3000-10700 min-1 or 500-3600 min-1, depending on the motor size, power input and load.
The motor is available in two material variants:
• MSF 3 is the standard version made of stainless steel DIN W.-Nr. 1.4301
• MSF 3 N is made of stainless steel DIN W.-Nr. 1.4401.
The motor has three internal limitations:
• maximum power input (P1)
• maximum current of 8,4 A or 12 A
• maximum speed of 10700 min-1 or 3600 min-1.
The pump delivers its maximum performance when one of the above limitations is reached.
Supply voltage
Flexible regarding power supply and power range, the motor can be supplied with either DC or AC voltage:
• 30-300 VDC, PE (100-300VDC for 2500W motor)
• 1 x 90-240 VAC - 10 %/+ 6 %, 50/60 Hz, PE.
CU 200 SQFlex control unit
CU 200 is a combined status, control and communication unit designed for the SQFlex system. Moreover, CU 200 enables the connection of a level switch placed in a water reservoir or tank.
CIU 903 SQFlex control unit for remote monitoring
CIU 903 is a combined monitoring, control and communication unit designed to work directly with a SQFlex pump. When combined with a CIM 280 GRM module, it enables remote monitoring through Grundfos Go. Moreover, CIU 903 can be connected to a start/stop switch, a level switch or a pulsating water meter.
It also works with Grundfos GO. IO 50 SQFlex switch box The IO 50 is a switch box designed for switching the system power supply on and off.
IO 101/IO 101 B SQFlex switch box
The IO 101/IO 101 B is a switch box designed for switching the system power supply on and off.
The IO 101/IO 101 B is used in solar-powered SQFlex systems with a backup generator.
Charge controller
The charge controller is used when a battery backup system is installed with an SQFlex pumping system.
Solar modules
The Grundfos solar modules are developed specifically for the SQFlex system. The solar modules are equipped with plugs and sockets enabling easy connection in parallel.
The number of the required solar modules depends on the following:
• quantity of water
• head
• location of installation.
For further information on solar modules, contact Grundfos.
Generator
In case the primary power supply is temporarily insufficient, the SQFlex system can be powered by a diesel- or gasoline generator.
Batteries
The SQFlex system can be powered by batteries with a 30-300 VDC voltage supply of and a maximum current of 8.4 A. DC power supply operation is limited to the highest possible power depending on the voltage. For example, 48 VDC provides a limiting maximum power of 403 W.
Pumped liquids
SQF pumps are applicable in thin, clean, non-aggressive and non-explosive liquids that do not contain solid or longfibred particles.
pH value: 5-9.
Liquid temperature: 0-40 °C (32-104 °F).
The pump can run at free convection (~ 0 m/s, 0 ft/s) at maximum 40 °C (104 °F).
Sand content
Maximum sand content: 50 g/m3 (50 ppm).
A higher sand content considerably reduces the lifespan of the pump.
Salt content
The table below shows the resistance of stainless steel to Cl-. The values in the table are based on a pumped liquid with a pH value of 5 to 9.
Curve conditions
Performance range, SQFlex Solar
The SQFlex Solar performance range in is based on the following data:
• solar radiation on a tilted surface (tilt angle: 20°)
• HT = 6 kWh/m2 (0.56 kWh/ft2) per day
• ambient temperature: 30 °C (85 °F)
• 20° northern latitude.
Performance range, SQFlex Wind
The SQFlex Wind performance range in is based on the following data:
• average wind speed (measured over a month)
• calculations according to Weibull's factor k=2
• continuous operation over 24 hours.
Specific performance charts
The specific performance charts are based on the following guidelines:
• All curves show mean values.
• The curves must not be used as guarantee curves.
• The typical deviation is: ± 15 %.
• The measurements are made at a water temperature of 20 °C (68 °F).
• The curves apply to a kinematic viscosity of 1 mm2/s
(1 cSt). If the pump is used for liquids with a viscosity higher than water, it reduces the head and increases the power consumption.
Pressure loss
The QH curves are inclusive of inlet and valve losses at actual speed.
2.Features and benefits
Dry-running protection
The SQF pump is protected against dry running to prevent damage to the pump. The dry-running protection is activated by a water level electrode placed on the motor
cable 0.3 to 0.6 m (12 to 24 in) above the pump, depending on the pump type.
The water level electrode measures the contact resistance to the motor sleeve through the water. When the water level falls below the water level electrode, the pump stops. The pump automatically restarts five minutes after the water level is above the water level electrode.
High efficiency
The MSF 3 motor is a permanent-magnet motor (PM motor) featuring a higher efficiency within the power range compared to a conventional asynchronous motor.
In addition, the segmented motor stator also contributes to high efficiency.
The MSF 3 motor is characterized by a high locked-rotor torque even at low power supply.
Over- and undervoltage protection
Over- and undervoltage may occur in case of unstable power supply or a defective installation.
The pump stops if the voltage falls outside the permissible voltage range. The motor automatically restarts when the voltage returns within the permissible voltage range. No extra protection relay is needed.
Note: The MSF 3 motor is protected against transients from the power supply according to EN/IEC 61000-4-5 (6 kV). In areas with high lightning intensity, we use external
lightning protection.
Overload protection
In case the upper load limit is exceeded, the motor automatically compensates by reducing the speed. If the speed falls below the minimum speed, the motor stops automatically.
The motor remains stopped for 30 seconds, then the pump automatically restarts.
The overload protection prevents the burnout of the motor.
No extra motor protection is required.
Overtemperature protection
A permanent-magnet motor gives off a small/negligible amount of heat to its surroundings. In combination with an efficient internal circulation system leading the heat away from the rotor, stator and bearings, optimal operating conditions are ensured for the motor.
As an extra protection, the electronic unit has a built-in temperature sensor. When the temperature rises above 85 °C (185 °F), the motor automatically stops. Once the
temperature drops to 75 °C (165 ° F), the motor automatically restarts.
Maximum Power Point Tracking
The built-in electronic unit gives the SQFlex system a number of advantages compared to conventional products. One of these advantages is the built-in microprocessor with Maximum Power Point Tracking (MPPT).
Due to the MPPT function, the pump duty point is continuously optimized according to the available input power. MPPT is only available for pumps connected to DC
supply.
Wide voltage range
The wide voltage range enables the motor to operate at any voltage from 30-300 VDC (100-300 VDC for 2500 W) or 90-240 VAC. This ensures easy installation and sizing.
Reliability
The MSF 3 motor is developed to achieve high reliability through the following features:
• carbon/ceramic bearings
• excellent starting capabilities
• various protection facilities.
Installation
Low weight ensures user-friendly handling.
• low weight ensuring user-friendly handling.
• installation in 3'', 4'' or larger boreholes.
• A motor starter/starter box is not needed.
• SQF is available with cable and socket.
Note: Horizontal installation requires the water level electrode to be placed minimum 0.3 to 0.6 m (12 to 24 in) above the pump to ensure the dry-running protection.
Service
The modular pump and motor design facilitates installation and service. The cable and the end cover with socket are fitted to the pump with screws to enable replacement.
The following are the SQF series
SQF 5A-3(N)
SQF 5A-7(N)
SQF 5-70(N)
