OT.DRP

4" three-phase oil-cooled motor (3x380-415V / 50Hz)

Electric motors from series OT are 2 pole asynchronous three-phase submersible motors designed to operate coupled to hydraulic parts with 4” Nema standard. Strong and reliable, they are made of materials suitable for contact with water and oil-cooled by FDA - Food Drug Administration approved dielectric fluid. OT motors require a start, operation and protection system.
Supply cable connector, removable for quick and easy maintenance is equipped with the DRP protection device. The DRP is an electronic device, integrated into the connection cable that guarantees optimal protection of the submersible pump against dry running and other possible installation faults or operation failures. In case of water shortage, the DRP stops the pump when the water is below its sensor. The DRP (observing a programmed time) restarts the motor when the water rises above its sensor.
 
APPLICATIONS
OT oil-cooled motors ensure reliable working in 4” or larger diameter wells and are designed to be used for lifting, distribution, and pressurisation of water in water systems.
 
CHARACTERISTICS OF CONSTRUCTION
  • 2 pole asynchronous three-phase oil-cooled motor.
  • Rewindable stator and rotor immersed in dielectric fluid (FDA approved).
  • Oversized axial and radial oil-lubricated bearings to guarantee longer life to the motor.
  • The pressure compensation inside the motor is ensured by a special internal diaphragm.
  • Sand protection to guarantee optimal operation even with sand in the borehole.
  • Motor bottom cover for extra protection and safety.
  • Removable lead connector to make installation and maintenance easier.
  • Supply cable according to drinking water regulations (ACS), available in different lenghts.
  • DRP protection device integrated into the connection cable available for all powers

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  • kW: 0,37 - 4
  • Voltage range: 3x380-415V / 50Hz
  • Flange: 4" NEMA standard dimensions
  • Voltage tolerance 50Hz from nominal: +6% / -10% Un
  • Rotation: reversible
  • Degree of protection: IP 68
  • Insulation: F
  • Rated ambient temperature: max 40° C
  • Cooling flow: min 8 cm/sec
  • Maximum quantity of suspended sand: 600 g/m3
  • Maximum starts/h: 150, equally distributed
  • Mounting: vertical/horizontal
  • Maximum immersion depth: 150 m
  • Allowed range of water pH: 6,4 - 8,0
  • Thrust: 1.500 N, 2.500 N, 4.500 N (according to ranges)
  • Protection requirements: For OT motors an overload protection and a control unit for motor start and run must be installed according to EN 60947-4-1 trip time < 10 sec. at 5xIn.

Automatic protections

Dry-running protection

Dry-running protection

The DRP completely protects the OT.DRP motor against lack of water in the well, without the aid of other equipment (probes, cables, sensors, control panels etc.). In case of dry running, the DRP automatically stops the OT.DRP motor. When the water level is restored in the well, the DRP restarts it after a programmed cycle time.

Protection against too frequent start&stops

Protection against too frequent start&stops

The DRP will protect the pump against leaks in the piping system (also when the pressure tank is exhausted or its membrane is defective, or when there is a defective pressure switch) and too frequent starts and stops (for example if the tank is too small for the system). In such cases to avoid potential damages, the DRP, after some automatic re-start attempts, makes the OT.DRP motor enter the stand-by mode.

Current overload protection

Current overload protection

The OT.DRP motor is protected against overload. In case the pump is partially o totally blocked, the DRP, after some automatic re-start attempts, makes it enter the stand-by mode.

Low voltage protection

Low voltage protection

The DRP protects the OT.DRP motor against low voltage. Low voltage can occur, for example, if the section of the power cable is not adequate considering the motor power and the distance between the plug and the pump itself; or if a generator is faulty or undersized for the pump.

Phase-loss protection

Phase-loss protection

The DRP protects the pump against phas-loss (for example caused by a brake of a fuse). The DRP protects the motor against damaging.

Information on a proper installation

  • Before installation, it is necessary to verify technical requirements of the given hydraulic part (thrust, power) to select the correct motor.
  • If you are using a generator with an internal combustion engine, it is necessary that the generator’s power measured in kW (in continuous delivery) is three times the rated power in kW of the submersible pump.
  • We recommend to install a proper cooling jacket in installations bigger than 10 cm, to guarantee the correct motor cooling flow.
  • The maximum quantity of sand allowed in the pumped water is 120 g/m³.
  • The DRP must NOT be used with a frequency inverter.
  • DRP doesn’t work with demineralized water (such as rain water).
  • DRP must not be used as a float.
  • The DRP must be immersed in the same water as the pump in order to ensure continuity between the DRP and the pump casing.
  • In order to reset the electronic protection, disconnect the pump power, wait 10 seconds, then plug it in again.

 

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