The TSURUMI 50C2.75 is the smallest three-phase model in Tsurumi's C series of submersible sewage pumps with cutter impeller. It has a 50 mm discharge and a 0.75 kW 2-pole three-phase dry-type induction motor (IP68, continuous-duty rated). Its semi-open single-channel cutter impeller is grey cast iron with a brazed sintered tungsten carbide edge, working against a serrated ductile-iron suction cover to shred fibres and debris in the sewage so they pass through instead of clogging the pump. It is designed to drain sewage and wastewater from buildings and kitchens, and to transfer sewage and wastewater in the treatment facilities of factories and commercial complexes.
Selection note: the 50C2.75 is a three-phase pump and needs a three-phase supply. If only single-phase power is available, choose the capacitor-start single-phase 50C2.75S. The C series are cutter pumps: they are not grinder (macerator) pumps, and they are not slurry pumps for construction mud or sand.
Key features
- Tungsten carbide cutting system: grooves on the front of the suction cover catch fibrous matter, which the sintered tungsten carbide edge on the impeller and the serrated suction cover then shred, preventing clogging by fibres. In Tsurumi's official demonstrations, C-series pumps cut aluminium cans, plastic bottles, non-flushable wipes and nylon pantyhose.
- Dual inside mechanical seals: running in an oil chamber, with ceramic + carbon upper faces and silicon carbide + silicon carbide (SiC) lower faces.
- Oil Lifter (Tsurumi patented design): keeps lubricating and cooling the seal faces even when the oil drops to one third of its normal level.
- Built-in circle thermal protector (CTP): cuts the motor circuit directly on overheating or overcurrent.
- Anti-wicking cable entry: stops water creeping into the motor by capillary action if the sheath is damaged or the cable end is submerged, and keeps moist air and condensation out of the motor.
- Maintenance-free bearings: permanently lubricated, double-shielded C3 deep-groove ball bearings.
- Guide rail ready: with a Tsurumi TOS guide rail fitting, the pump is lowered onto the duckfoot bend and lifted out for service without anyone entering the sump.
Applications
- Buildings: sewage and wastewater drainage
- Kitchens: kitchen sewage and wastewater drainage
- Factories and commercial complexes: sewage and wastewater transfer in treatment facilities
Suitable liquids are sewage, wastewater and water carrying solids, at 0–40 °C and pH 5–9.
Performance
The 11.5 m maximum head is the head at near-zero flow, and the 335 L/min (about 20.1 m³/h) maximum capacity is the end point of the performance curve (50 Hz). The two do not occur together: actual flow falls as total head (static head plus pipe friction loss) rises. Select the pump from the performance curve using your installation's total head. For more flow, consider the 80C21.5 (810 L/min); for more head, the 80C22.2-CR (21 m).
Technical specifications
TSURUMI 50C2.75 technical specifications
| Item | Specification |
|---|
| General |
|---|
| Model | 50C2.75 (guide rail version: TOS50C2.75) |
|---|
| Series | C series (submersible sewage pump with cutter impeller) |
|---|
| Discharge bore | 50 mm |
|---|
| Discharge connection | Threaded oval flange (free-standing); threaded JIS 10 kg/cm² flange on guide rail fitting |
|---|
| Hydraulic performance (50 Hz) |
|---|
| Max. head (at zero flow) | 11.5 m |
|---|
| Max. capacity (curve end point) | 335 L/min (approx. 20.1 m³/h) |
|---|
| Solids passage | 31 × 27 mm (50 Hz); 28 × 27 mm (60 Hz) |
|---|
| Electrical |
|---|
| Motor output | 0.75 kW |
|---|
| Motor | 2-pole dry-type induction motor, IP68, continuous-duty rated |
|---|
| Insulation class | F or E (as per nameplate) |
|---|
| Synchronous speed | 3,000 / 3,600 min⁻¹ (50 / 60 Hz) |
|---|
| Power supply | 3-phase (voltage as per nameplate) |
|---|
| Starting method | Direct-on-line (D.O.L.) |
|---|
| Motor protection | Built-in auto-reset circle thermal protector (CTP) |
|---|
| Leakage sensor | Not built in; external electrode-type sensor available as an option |
|---|
| Seals and bearings |
|---|
| Shaft seal | Dual inside mechanical seals with Oil Lifter; upper faces ceramic + carbon, lower faces SiC + SiC |
|---|
| Oil seal | Nitrile rubber (NBR) |
|---|
| Lubricant | Turbine oil ISO VG32, 440 ml |
|---|
| Bearings | Permanently lubricated, double-shielded C3 deep-groove ball bearings |
|---|
| Materials |
|---|
| Impeller | Semi-open single-channel cutter, grey cast iron with brazed sintered tungsten carbide edge |
|---|
| Suction cover | Ductile cast iron (serrated) |
|---|
| Pump casing | Grey cast iron |
|---|
| Motor frame | Grey cast iron |
|---|
| Shaft | 420 stainless steel |
|---|
| Cable |
|---|
| Cable | PVC, 6 m, 1 × 4 × 1.25 mm², O.D. 11.1 mm |
|---|
| Liquid limits |
|---|
| Liquid | Sewage, wastewater and water carrying solids |
|---|
| Liquid temperature | 0–40 °C |
|---|
| pH | 5–9 |
|---|
| Dimensions and weight |
|---|
| Dimensions (L × W × H), free-standing | 405 × 250 × 415 mm |
|---|
| Dimensions (L × W × H), guide rail fitting | 621 × 250 × 458 mm |
|---|
| Dry weight (excl. cable) | 24 kg free-standing; 23 kg guide rail (excl. duckfoot bend) |
|---|
Sources: Tsurumi C-series catalogue (IA112), Tsurumi C-series product guide and Tsurumi Europe C-series data (performance at 50 Hz). Voltage and rated current of the Hong Kong supply version are as per the nameplate and confirmation from the Hong Kong agent.
C series comparison: 50–80 mm 2-pole models
Tsurumi C series model comparison (50 Hz)
| Model | Discharge | Power / supply | Max. head | Max. capacity | Solids passage |
|---|
| 50C2.75 (this product) | 50 mm | 0.75 kW 3-phase | 11.5 m | 335 L/min | 31 × 27 mm |
|---|
| 50C2.75S | 50 mm | 0.75 kW 1-phase | 11.5 m | 335 L/min | 31 × 27 mm |
|---|
| 80C21.5 | 80 mm | 1.5 kW 3-phase | 13.2 m | 810 L/min | 43 × 60 mm |
|---|
| 80C22.2-CR | 80 mm | 2.2 kW 3-phase | 21 m | 750 L/min | 22 × 31 mm |
|---|
| 80C23.7-CR | 80 mm | 3.7 kW 3-phase | 29 m | 650 L/min | 22 × 31 mm |
|---|
| 80C25.5-CR | 80 mm | 5.5 kW 3-phase | 32 m | 1,340 L/min | 29 × 23 mm |
|---|
| 80C27.5-CR | 80 mm | 7.5 kW 3-phase | 38 m | 1,000 L/min | 26 × 25 mm |
|---|
| 80C211-CR | 80 mm | 11 kW 3-phase | 47 m | 1,200 L/min | 26 × 26 mm |
|---|
The "-CR" suffix means the impeller and suction cover are high-chromium cast iron (not chrome plating) for greater wear resistance. The 50C2.75 is not a CR model.
Optional accessories
- Discharge bend BEND 50 (oval flange): according to the Tsurumi product guide, this model is supplied without a discharge bend as standard. Please confirm the Hong Kong supply scope with us.
- Guide rail fitting TOS3-50: the pump then becomes model TOS50C2.75. The set includes a duckfoot bend, guide support (with bolts and nuts), guide hook, 5 m lifting chain (with shackles) and a threaded JIS 10 kg/cm² flange. The guide pipe is not included.
- Float switches (level control): MC-2 heavy-duty float switch (with shock absorber, NO or NC contact) or MT-1 economy teardrop float switch (SPDT, for filling or emptying). Three-phase pumps must be connected through a control panel.
- External electrode-type leakage sensor.
- Factory options on request: seawater-resistant version, high-temperature version for liquids up to 80 °C, and special materials such as a high-chromium cast iron impeller and suction cover.
Safety and installation
- Three-phase power connection and control panel wiring must be carried out by a registered electrical worker in line with local regulations. Earth the pump properly and provide overload and earth-leakage protection.
- The built-in thermal protector resets automatically: after a trip, the motor restarts by itself once it cools. Isolate and lock out the power before touching the pump or its impeller.
- The tungsten carbide impeller edge and the serrated suction cover are sharp. Switch off the power and wear cut-resistant gloves before clearing debris.
- Lift the pump by its handle or a lifting chain, never by the cable. The free-standing dry weight is 24 kg.
- During installation, do not damage the cable sheath or let the cable end become submerged. The anti-wicking entry is a safeguard, not a substitute for care.
- Avoid prolonged dry running. Do not pump liquids above 40 °C or outside pH 5–9. The pump is not explosion-proof, so never use it for flammable or explosive liquids. The standard model is not seawater-resistant.
- Sewage sumps are confined spaces that may contain hydrogen sulphide or lack oxygen. Follow Hong Kong confined-space regulations before entry; a guide rail fitting lets you lift the pump out for service from outside the sump.
Wear parts and routine checks
- Main wear parts: impeller (tungsten carbide edge), suction cover, mechanical seals and oil seal.
- Check the oil in the oil chamber (turbine oil ISO VG32, 440 ml) regularly as described in the manual. If the oil is cloudy or contains water, have the shaft seals inspected promptly.
- If flow drops noticeably or debris often wraps around the impeller, check the impeller edge and suction cover for wear.
