Grundfos SEG.40.12.2.50B Pump

Spare Parts for  SEG.40.12.2.50B Grinder Pump

This page lists replacement and compatible spare parts for Grundfos pumps.
Pump Spares Direct is an independent supplier and is not affiliated with, endorsed by, or authorised by Grundfos.

Image shown for pump identification purposes only.

Product Summary 

The Grundfos SEG.40.12.2.50B is a 1.2 kW three-phase submersible grinder pump designed for pressurized sewage pumping in domestic and municipal applications. Equipped with a patented grinder system, it efficiently reduces solids to allow transport through small-diameter pipes (DN 40). The pump features a clamp connection for easy disassembly and the SmartTrim system for maintaining impeller clearance.

  • Patented Grinder System: Effective maceration of organic solids allows the use of smaller, cost-effective discharge piping.
  • SmartTrim Adjustment: Enables easy external adjustment of the impeller clearance to restore factory efficiency without dismantling the pump.
  • Watertight Cable Plug: Polyurethane-filled stainless steel cable connection prevents water from penetrating the motor windings.
  • Clamp Connection: A stainless steel clamp secures the motor to the pump housing, facilitating quick service and rotation of the outlet.
  • Cartridge Shaft Seal: The primary and secondary seals are combined into a single, easy-to-replace cartridge unit.

DOWNLOAD DATASHEET

Spare Parts List

Select the required parts below to include them in your quote request.

Select Qty Part Number Description Material / Spec
1 96076121 Grinder System Kit (Head, Ring, Screw) Standard
1 96076122 Shaft Seal Complete (0.9-1.5 kW) NBR
1 96076116 Impeller Complete (w/ Nut & Key) Cast Iron
1 96076125 O-Ring Service Kit (0.9-1.5 kW) NBR
1 96076124 Shaft with Rotor Complete -
1 96690420 Lifting Bracket Kit Stainless Steel
1 96586753 Shell Ondina X420 Oil Paraffinic Oil
1 Pos. 44 Grinder Ring Hardened Steel
1 Pos. 45 Grinder Head Hardened Steel
1 Pos. 92 Clamp Stainless Steel
1 Pos. 50 Pump Housing Cast Iron
1 Pos. 105 Shaft Seal Unit -
2 Pos. 193 Oil Screw -
1 Pos. 68 Adjusting Nut (Impeller) -

OEM part numbers are referenced for identification purposes only.
All parts listed are suitable for use in Grundfos SEG.40.12.2.50B. 

Exploded Parts Views 

Exploded view shown for reference only. Part numbering may vary by configuration.

Key Technical Specifications 

Parameter Value
Model / Curve SEG.40.12.2.50B
Rated Power 1.2 kW (1.6 HP)
Voltage / Frequency 3 x 400-415 V / 50 Hz
Rated Current See Nameplate (Approx. 2.4 - 3.0 A)
Discharge Connection DN 40 (Horizontal Flange)
Impeller Type Semi-open with Grinder
Installation Type Submersible (Auto-coupling or Free-standing)

Troubleshooting, Common Faults & Solutions

Pump does not start / Fuses blow

Likely Cause: Power supply failure, locked impeller, or cable defect.

Action / Part: Check cable/motor windings and clean the Impeller (Pos. 49)[cite: 1026].

Pump runs but no liquid is delivered

Likely Cause: Outlet valve closed, non-return valve blocked, or air lock.

Action / Part: Clean valves and vent the pump by tilting it[cite: 1042].

Motor protector trips shortly after start

Likely Cause: Impeller clearance incorrect or voltage drop.

Action / Part: Adjust impeller clearance via Adjusting Nut (Pos. 68) or check voltage[cite: 1028].

Below-standard performance

Likely Cause: Wrong direction of rotation or worn grinder.

Action / Part: Swap two phases (if 3-phase) or replace Grinder System (Kit 96076121)[cite: 1040].

Pump is blocked

Likely Cause: The grinder system is worn or jammed.

Action / Part: Replace the Grinder System[cite: 1045].

Online Resources

Alt image
Request for Quotation

Request for Quotation

Thank you!

Your Request for Quote has been successfully sent.
Our team is reviewing your requirements and will be in touch shortly.

Selected Parts:

  • No parts selected
Please enter your full name
Please enter your company name
Please enter a valid email address
Please enter your phone number

Drag & drop image here or click to browse

Accepted formats: JPG, PNG, PDF (Max 5MB)

File size must be less than 5MB
Please select delivery urgency
Please select delivery location
Note on Minimum Orders: A standard minimum order value (MOV) of $1,000 AUD typically applies to process B2B commercial orders efficiently.

We typically respond within 24 hours