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Grundfos 96437852 CU301 SmartFlo Transducer only


  • 40020
  • Save $44

Model #: 96437852-Trans    

For SmartFlo electronic constant pressure submersible pump.
3-Inch SQE Submersible Well Pumps 
Transducer 0-120 psi 1/2" npt 10' cord ONLY :
Constant pressure with SmartFloTM
Intelligent Control Box

CU 301 is specially designed for the Grundfos SQE 3" submersible pump to provide a constant pressure water package solution. The CU 301 is an intelligent control unit which capable of monitoring and displaying the system’s performance continuously whilst also providing a variety of protection features that guarantee a long lifetime of the pump.

Constant Water Pressure
There are numerous benefits of using CU 301 with the SQE pump, but none can outweigh the constant water pressure feature. The CU301/SQE package is the system that can turn the luxury idea of constant pressure to reality. You can always get what you expect when you turn on the tap.

Adjustable Water Pressure
All at the touch of one single button – you can adjust the water pressure from 2 – 5 bars at any time. Not only the water pressure will remain constant at your desired pressure level, the intelligent yet simple communication between SQE and CU 301 means the system will respond swiftly to the newly adjusted pressure level and provide instant comfort to the end users.

Easy to Use
The intelligent CU 301 box promises to do all the jobs for you. The only task for the end users is to switch on the box and choose the desired water pressure level through the super user-friendly operating interface. The system will delivers the comfortable water supply with the effort of pressing just two buttons on the box. The box displays pump information status in an easy-to-understand graphical way so it is easy to operate and monitor.

Constant Pressure System
With the user-friendly operating interface, the CU301 box is very suitable for daily domestic and small irrigation use. By choosing the water pressure on the box surface, end users can change the water pressure as frequent as needed.

Operation Monitoring
The CU301 receives signals from the pressure sensor constantly. Should the pressure dropped below the desired pressure level, the CU301 will operate the SQE pump automatically until the water pressure level restored to the desired level and the signal light on the display will indicate that the pump is running at the moment. Here is the five operating functions on the display cover:

On/off button
Button lock indication
System Pressure setting and indication
Indication of operation
Service alarm indication
Operating Relay
The operating relay can be used to operate an external equipment or add an additional sensor signal.
Service Alarm Indication
The pump will detect and give the below alarm signals:
Dry running of the pump
Service alarm will be permanently on if one of the following situations arises:
Defective sensor
Speed Reduction
Voltage alarm
No contact to pump
The Grundfos range of SmartFlo systems are complete packages, from a single supplier, designed to provide constant water pressure in any home, irrigation or small commercial application. The SmartFlo system will constantly adapt pump performance to meet the demand for water. Even if every member of a household is using water at the same time – in the shower, in the kitchen, to wash the car, and to irrigate the lawn – the SmartFlo system makes sure that the water pressure remains constant.


CU301 User Interface

The CU301 User Interface is the easy to use command and control computer for operating the pump in constant pressure mode. The user simply chooses the desired water pressure by pressing the UP or DOWN arrows, and the CU301 does the rest.

In order to control pressure, it must be measured. The included pressure sensor precisely measures water pressure sending its signal to the CU301. The CU301 reads this pressure signal and then electronically commands the pump to start, stop, speed up, or slow down in order to maintain constant pressure regardless of water demand. It controls the pump via power line communications by impressing high speed data messages on the pumps power supply cable. This technology is similar to that used in a home intercom or a baby monitor.


  • Domestic water supply
  • Light commercial
  • Irrigation
  • Tank Application
  • Pressure boosting
Features and benefits

Dry-running protection

The pumps are protected against dry running. A value of pcut-out ensures cut-out of the pump in case of water shortage in the borehole, thus preventing a burnout of the motor. Pcut-out is factory-set both for the SQ and SQE pump.

Protection against upthrust

Starting up a pump with a very low counter-pressure involves the risk of the entire impeller stack being lifted. This phenomenon is called upthrust. Upthrust may cause breakdown of both pump and motor. The motors are fitted with an upthrust bearing protecting both pump and motor against upthrust and thus preventing breakdown during the critical start-up phase.

Excellent starting capabilities

The integrated electronic unit of the motor features soft starting. Soft starting reduces the starting current and thus gives the pump a smooth and steady acceleration. The soft starter minimises the risk of wear of the pump and prevents overloading of the mains during start-up. The excellent starting capabilities are a result of the high locked-rotor torque of the permanent-magnet motor together with the few pump stages. The high starting reliability also applies in case of low voltage supply.

High pump efficiency

The hydraulic pump components are polyamide-reinforced with 30 % glass fibre.
The hydraulic design ensures high pump efficiency meaning low energy consumption and thus low energy costs.

High motor efficiency

The motors are designed according to the permanent-magnet principle (PM motor) featuring high efficiency within a wide performance range.

Over-voltage and under-voltage protection

Overvoltage and undervoltage may occur in case of unstable voltage supply. The integrated protection of all motors prevents damage to the motor in case the voltage moves outside the permissible voltage range. The pump will be cut out if the voltage falls below 150 V or rises above 315 V. The motor is automatically cut in again when the voltage is again within the permissible voltage range. Therefore no extra protection relay is required.

Overload protection

If the pump is exposed to heavy load, the current consumption will rise. The motor will automatically compensate for this by reducing the speed. If the speed falls below 3000 min-1, the motor will be cut out. If the rotor is being prevented from rotating, this will automatically be detected and the power supply will be cut out. Consequently, no extra motor protection is required.

Wear resistance

The pump impellers are not fastened to the shaft ("floating"). Each impeller has its own tungsten carbide/ceramic bearing. The design and the materials chosen ensure high wear resistance to sand and thus long product life.

Over temperature protection

A permanent-magnet motor gives off very little heat to its surroundings. In combination with an efficient internal circulation system leading the heat away from the rotor, stator and bearings, this ensures optimum operating conditions for the motor. As an extra protection, the electronic unit has a built-in temperature sensor. When the temperature exceeds a critical limit, the motor is cut out. When the temperature has dropped, the motor is automatically cut in again.


The motors have been designed with a view to high reliability and have the following features:

  • tungsten carbide or ceramic bearings
  • thrust bearings protecting against downthrust
  • product life equal to conventional AC motors.

Variable speed

The MSE 3 motor enables continuously variable speed control within the range from 3,000 to 10,700 min-1. The pump can be set to operate in any duty point within the 3,000 and 10,700 min-1 performance range of the pump. Consequently, the pump performance can be adapted to any specific requirement.

The variable-speed control facility requires the use of a CU 300 or CU 301 control unit and the R100 remote control. 

Excellent for home water pressure pumping systems
  • Dry-run protection
  • High efficiency pump and motor
  • Protection against up-thrust
  • Soft-start
  • Over-voltage and under-voltage protection
  • Overload protection
  • Over-temperature protection
  • High starting torque
  • Constant pressure control
  • Variable speed regulation
  • Electronic control and communication
  • Push button pressure setpoint adjustment
  • Low well water indicator
  • Pump running indicator
  • Keypad lockout
  • High quality stainless steel pressure sensor
  • Built-in diagnostics
  • Knowledge that Grundfos backs its products with clearly defined warranty terms
  • Warranty claims with well-defined contacts and short response time.


Comprehensive and global 2-year warranty included in pump sales price

All Grundfos products come with a 2-year warranty that fully complies with legal requirements.

Warranty when installed by a GRUNDFOS WATERPRO DEALER,  Extended 5 Year Warranty. 

The warranty covers product and material defects which are not the results of normal wear and tear for a period of 24 months from the date of delivery. The warranty period may not, however, exceed 30 months from the date of production.

Warranty claims will be rejected in the following situations:
If the defect in the product arises from:

Any drawing, design or specification supplied by the customer/purchaser modifications undertaken by the customer/purchaser or athird party without the consent of Grundfos

If a defect is caused by: 

Normal wear and tear
Inadequate maintenance or faulty repair by others than Grundfos
Failure to observe the operating instructions
Use of any unsuitable material
The effects of chemical or electrolytic action
Building or assembly work not undertaken by Grundfos
Other reasons beyond Grundfos’ control.
As a general rule, Grundfos will not accept to pay transportation/replacement/installation costs for faulty products.
Warranty claims may be submitted by contacting the local Grundfos sales company or the point of sale.



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