SQFlex pumps have build-in protection features that protect the pump itself and in many cases the well. Among these features are:

Protection against dry-running

The SQF pump is protected against dry running in order to prevent damage to the pump. The dry-running protection is activated by a water level electrode placed on the motor cable 12-24 inches 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 will be cut out. The pump will automatically attempt to restart after the water level electrode is submerged again for 5 minutes.

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 to this, the segmented motor stator contributes considerably to the high efficiency. The MSF 3 motor is furthermore characterised by a high locked-rotor torque even at low power supply.

Over - and unde voltage protection

Overvoltage and undervoltage may occur in case of unstable voltage supply. The pump will be cut out if the voltage falls outside the permissible voltage range of 30 - 300VDC or 90 - 240VAC. The motor is automatically cut in again when the voltage is again within the permissible voltage range. As result, no additional voltage protection relay is needed.

NOTE: The MSF 3 motor is protected against transients from the voltage supply according to IEC 60664-1 "overvoltage category III" (4kV). In areas with high lightning intensity, external lightning protection is recommended.

Overload protection

If the upper power input limit is exceeded or if the pump is blocked, the motor will automatically compensate by reducing the speed. If the speed falls below 500rpm, the motor will be cut off automatically. The motor will remain cut out for 10 seconds after which it will attempt to restart. The overload protection prevents burnout of the motor. As result, no additional motor protection is required.

Overtempearture protection

A PM 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 fact ensures optimum operating conditions for the motor. As an extra protection, the electronic unit has a built-in temperature sensor. When the temperature rises above 185F, the motor is automatically cut out; when the temperature drops to 165F, the motor is automatically cut in again.

Maximum power point tracking (MPPT)

The built-in electronic unit gives the SQ Flex system a number of advantages compared to conventional products. One of these is the built-in microprocessor with MPPT. Thanks to the MPPT function, the pump duty point is continuously optimised according to the input power available. MPPT is only available when the pump is connected to a DC power source.

Wide voltage range

The wide voltage range enables the motor to operate at any volatge from 30-300VDC or 90-240VAC.

CENTRIFUGAL PUMP (4")
Technology based on 30 years' experience enables high flow in shallow water conditions. Stainless steel components give high wear resistance.