Wilo-Zetos K 8

Series description


Multistage 8" stainless steel cast submersible pump in sectional construction for vertical and horizontal installation


  • Process water and water supply from boreholes and rainwater storage tanks in communal and industrial applications
  • Pumping drinking water with ACS approval
  • Pumping water for sprinkling and irrigation
  • Ground water lowering
  • Pressure boosting
  • Pumping water in offshore areas and in fire extinguishing systems
  • Utilisation in geothermal and thermal applications
  • Water control in mines and mining applications

Type key

Example:Wilo-Zetos K8.130-17 + NU 701-2/130
8Diameter of the hydraulic unit in inches ["]
130Volume flow in the best point at 50 Hz in m³/h
17Number of hydraulic stages
Motor:NU 701-2/130
NUSubmersible motor
701Size (5…, 6... = 6"; 7…, 8… = 8")
2Number of poles
130Nominal motor power in kW

Special features/product advantages

  • High pump efficiency of up to 84.5 %
  • A previously unequalled total efficiency of more than 75 % in this class with permanent magnet rotor
  • Particularly corrosion-resistant thanks to hydraulics comprised entirely of cast stainless steel in 1.4408 (AISI 316)
  • High wear resistance: max. sand content of 150 g/m³
  • ACS approved for domestic water applications
  • Easy maintenance, simple to dismantle system

Technical data


  • Max. volume flow: 200 m³/h
  • Max. delivery head: 620 m
  • Max. fluid temperature: 70 °C
  • Max. sand content: 150 g/m³
  • Pressure connection: G 5/PN 63


  • Mains connection: 3~400 V, 50 Hz ±10 %
  • Max. fluid temperature: 30 °C at 0.16 or 0.5 m/s minimum flow at the motor; 20 °C at 0.1 m/s minimum flow at the motor; higher temperatures on request
  • Immersed operating mode: S1
  • Max. number of starts: NU 5... / NU 6… / NU 7… = 20/h; NU 8.. = 10/h
  • Max. immersion depth: NU 5… NU 7… = 350 m; NU 611, NU 811 = 100 m; NU 801 = 300 m
  • Protection class: IP 68
  • Control range for frequency converter: NU 5... / NU 611 / NU 7… / NU 811 = 30-50 Hz; NU 801 = 25-50 Hz


  • Multistage hydraulics with semi-axial impellers
  • Integrated non-return valve
  • NEMA coupling
  • Three-phase AC motor


Submersible pump for vertical or horizontal installation.


Multistage submersible-motor pump with semi-axial hydraulics. Housing parts and impellers made of stainless steel (1.4408). Pressure connection as threaded connection with non-return valve (optionally with accessory adapter on flange connection).


Three-phase motor for direct and star-delta start. Sealed, hermetically cast motor with enamel-insulated winding, resin-impregnated (NU 5…, NU 7…) or rewindable motor with PVC‐insulated winding (NU 611…, NU 8…). Motor shroud made of stainless steel, A2/A4 quality.

Hydraulic connection as standard NEMA connection. Sealing of motor shaft by the use of a mechanical seal made of solid silicon carbide material. Self-lubricating motor bearing. Thrust bearing with rockers for absorption of high axial thrust. Negative axial thrust is absorbed by the counter-thrust bearing.

Motors in the NU 5… and NU 7… series are filled with a water‐glycol mixture, motors in the NU 611 and NU 811 series are filled with a water-glycerine mixture. NU 611 and NU 8... series motors can also be filled with drinking water (T‐version). Frequency converter operation is permitted (SF 1.1).


The motor is cooled by the pumped fluid. The motor must always be immersed when operated. The limit values for maximum fluid temperature and minimum flow velocity must be adhered to. Vertical installation is possible with or without cooling jacket. For horizontal installation, bearing brackets must be used for reinforcement of the unit. An anti-vortex plate or cooling jacket may be used to improve the inlet flow.

Pressure shroud

The pressure shroud is used for the direct installation of the unit in the pipe network. Standard models are without mounted non-return valves. The maximum inlet pressure is 10 bar.


  • No suction mode is possible with these units!
  • The unit must be fully immersed in water during operation.
  • Horizontal installation is possible depending on the motor.
  • Drinking water version: When used for pumping drinking water in accordance with drinking water regulation, all components that come into contact with the fluid must be checked for their use. Optionally, a version with an ACS rating can be ordered!

Scope of delivery

  • Unit (hydraulics system + motor) premounted at the factory
  • Connection cable per customer request
  • Installation and operating instructions


  • Individual hydraulics without motor available
  • Drinking water version with ACS approval
  • Pt100 sensor for thermal motor monitoring
  • Adapter for flange connection

Duty chart

Duty chart Zetos K 8

3~400 V, 50 Hz, p = 1 kg/dm³, v = 1x10-6 m²/s, ISO 9906 Annex A, η = hydraulic efficiency



NEMA connection

Standardised connection

Integrated non-return valve

Without non-return valve


AC motor


Three-phase motor

Direct activation

Star-delta activation

FC operation

Motor with cast stator

Rewindable motor

Oil motor filling


Water-glycol motor filling

Drinking water motor filling


Hydraulics/motor preassembled


Horizontal installation

Vertical installation


Motor temperature monitoring, PT100


PTC motor temperature monitoring


Capacitor box for 1~230 V


Dry-running protection


Integrated lightning protection



Bearing brackets for horizontal installation


Cooling jacket


Non-return valve


Pressure shroud



Pump housing

Stainless steel

Pump housing (special version)

On customer request


Stainless steel

Impeller (special version)

On customer request

Motor housing

Stainless steel

Motor housing (special version)

On customer request


Certification Booklet Wilo-EMU D/DCH/K/KD/KM/NK/SCH / Wilo-Sub TWI/TWU / Wilo-Zetos K8 (w/o motor)

Article Number 6080455
Edition 1702
Version number 02
Page format A4
Number of pages 71

PDF (1 MB)


Certification Booklet Wilo-EMU NU/U-Motor

Article Number 6080454
Edition 1702
Version number 01
Page format A4
Number of pages 8

PDF (427 kB)


Certification Booklet Wilo-EMU / Wilo-Zetos + NU / U-Motor

Article Number 6074549
Edition 1702
Version number 04
Page format A4
Number of pages 53

PDF (935 kB)


Clean Water

Page format A4
Number of pages 24

PDF (8 MB)


General overview

Edition 2017
Page format A4
Number of pages 72

PDF (46 MB)


PDF: Wilo-Zetos K 8


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