The TSURUMI 50NHC2.75 is the smallest three-phase model in the NHC series (TSURUMI UNIVERSE brand), Tsurumi's submersible cutter sewage pump. It has a 50 mm discharge and a 0.75 kW 2-pole three-phase motor. The NHC series is designed for raw sewage, wastewater and heavy-duty industrial duty where pumps tend to clog on oversize material: two tungsten carbide alloy edges on the impeller vanes work against the serrated suction port of the suction cover, cutting rags, rope and other fibrous material as it enters, so it does not block the pump, discharge pipe or valves.
Selection note: this is the three-phase 50NHC2.75 (class H insulation, direct-on-line start). Tsurumi also makes a single-phase 50NHC2.75S (class F insulation, capacitor start and capacitor run) that shares the same performance curve, but Jaco does not sell the single-phase version, so please confirm a three-phase supply on site before ordering. The NHC is a sewage cutter pump, not a slurry pump; Tsurumi does not list it for construction-site mud, sand slurry or abrasive liquids.
Key features
- Cutter impeller: a semi-open two-channel impeller with two sintered tungsten carbide alloy edges brazed onto the vanes. They rotate on the serrated part of the suction cover and cut incoming fibrous material, preventing clogging in the discharge pipe and valves.
- Dual inside mechanical seals: silicon carbide (SiC) faces running in an oil chamber. Tsurumi's catalogue rates SiC at five times the corrosion, wear and heat resistance of tungsten carbide; the fixing-ring rubbers are NBR or FPM (FKM).
- Oil Lifter (a Tsurumi original design): keeps the seal faces lubricated and cooled down to about one third of the normal oil level, helping to extend seal life.
- Built-in circle thermal protector (CTP): cuts the motor circuit directly on excessive heat or overcurrent.
- Continuous-duty dry-type induction motor: 2-pole, 3000 min⁻¹ at 50 Hz, class H insulation.
- Anti-wicking cable entry: an NH-series feature that limits water creeping along the cable into the motor.
- Two installation options: free-standing, or the TOS50NHC2.75 guide rail version, which lets the pump be lifted out for maintenance without anyone entering the sump.
Applications
- Sewage and wastewater drainage: raw sewage and wastewater containing fibrous material
- Septic and purifying tanks: raw water transfer
- Wastewater treatment facilities and pumping stations: sewage lifting and transfer
- Flood prevention equipment: drainage duty
- Reservoirs at recreational facilities: drainage duty
These applications are taken from the NH-series catalogue. At 0.75 kW this model has limited head and flow, so check your site's total head against the performance data below first.
Performance
Read from Tsurumi's 50 Hz performance curve, the 50NHC2.75 reaches a maximum head of about 16 m, which is the head at near-zero flow. The curve ends at about 0.30 m³/min (about 300 L/min) at roughly 6 m head. The two do not occur together: actual flow falls as total head (static head plus hose and pipe friction loss) rises. These figures are curve readings for selection guidance only, not guaranteed duty points. Tsurumi advises against continuous operation along the dashed (low-flow) part of the curve. For more head or flow, see the larger models in the comparison below.
Technical specifications
TSURUMI 50NHC2.75 technical specifications (50 Hz)
| Item | Specification |
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| General |
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| Model | 50NHC2.75 (three-phase) |
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| Series | NHC (submersible cutter sewage pump, TSURUMI UNIVERSE brand) |
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| Discharge bore | 50 mm |
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| Discharge connection | Free-standing: threaded oval flange; guide rail: threaded JIS 10kg/cm² flange |
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| Guide rail model | TOS50NHC2.75 |
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| Hydraulic performance (approx., read from curve) |
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| Max. head (at zero flow) | approx. 16 m |
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| Max. capacity (curve end point) | approx. 0.30 m³/min (about 300 L/min) at about 6 m |
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| Impeller | Cutter (semi-open two-channel impeller with two tungsten carbide cutting edges) |
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| Electrical |
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| Motor output | 0.75 kW |
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| Motor | Continuous-duty rated dry-type induction motor, 2-pole, insulation class H |
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| Speed | 3000 min⁻¹ (50 Hz) |
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| Power supply | 3-phase 50 Hz (voltage as per nameplate) |
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| Starting method | Direct-on-line (D.O.L.) |
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| Motor protection | Built-in circle thermal protector (CTP) |
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| Leakage sensor | None |
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| Seals and lubrication |
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| Shaft seal | Dual inside mechanical seals, silicon carbide (SiC) faces, with Oil Lifter |
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| Lubricant | Turbine oil ISO VG32, 500 ml |
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| Materials |
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| Impeller | Gray cast iron with tungsten carbide alloy edges |
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| Suction cover | Ductile cast iron |
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| Pump casing | Gray cast iron |
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| Motor frame | Gray cast iron |
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| Shaft | 420 stainless steel |
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| Oil seal | Nitrile rubber (NBR) |
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| Power cable | Chloroprene rubber, 6 m |
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| Dimensions and weight |
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| Free-standing dimensions (L × W × H) | 380 × 216 × 414 mm |
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| Free-standing dry weight (excl. cable) | 26 kg |
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| Guide rail dimensions (L × W × H) | 596 × 216 × 486 mm |
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| Guide rail dry weight (excl. cable and duckfoot bend) | 23 kg |
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Sources: TSURUMI UNIVERSE NH-series submersible sewage pump catalogue (IA143, 50 Hz) and the NHC product page on tsurumiuniverse.com. Tsurumi does not publish a maximum liquid temperature, solids passage or pH range for this series. Voltage and rated current of the Hong Kong supply version are as per the nameplate and supplier confirmation. Tsurumi notes that specifications may change without notice, so request the factory specification sheet before use.
NHC series comparison: 50 mm models
Tsurumi NHC series 50 mm model comparison (50 Hz, performance approx. from curves)
| Model | Power | Max. head | Curve end flow | Free-standing dry weight |
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| 50NHC2.75 (this product) | 0.75 kW | approx. 16 m | approx. 0.30 m³/min (at about 6 m) | 26 kg |
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| 50NHC21.5 | 1.5 kW | approx. 19.5 m | approx. 0.43 m³/min (at about 7.8 m) | 41 kg |
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| 50NHC22.2 | 2.2 kW | approx. 23.5 m | approx. 0.55 m³/min (at about 12.8 m) | 44 kg |
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| 50NHC23.0 | 3.0 kW | approx. 32 m | approx. 0.50 m³/min (at about 21 m) | 51 kg |
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| 50NHC23.7 | 3.7 kW | approx. 32 m | approx. 0.67 m³/min (at about 22 m) | 56 kg |
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For an 80 mm discharge, see the 80NHC22.2, 80NHC23.0, 80NHC23.7 and 80NHC211.
Optional accessories
- Guide rail fitting (TOS): order it as the guide rail model TOS50NHC2.75. Tsurumi's set includes a duckfoot bend, guide support (with bolts and nuts), guide hook, 5 m lifting chain with shackles and a JIS 10kg/cm² flange. The guide pipe is not supplied and must be sourced locally. The guide rail version has a threaded JIS 10kg/cm² discharge flange, so pipework must match JIS 10K.
- Float switches (level sensors): the Tsurumi MC-2 is a heavy-duty float with a shock absorber for liquids with heavy suspended solids and scum, with selectable NO or NC contact; the MT-1 is an economy teardrop float for scum-laden wastewater, with an SPDT contact for filling or emptying control. On three-phase pumps, float switches are normally wired through a control panel rather than switching the motor directly.
- Control panel: this model starts direct-on-line and its built-in CTP cuts the motor circuit directly; use a control panel for automatic level-controlled operation.
- Lubricating oil: turbine oil ISO VG32; this model takes 500 ml.
Safety and installation
The first point below is from Tsurumi's catalogue; the rest is general installation guidance, not NHC-specific official text.
- Do not run the pump continuously on the dashed (low-flow) part of the performance curve.
- Three-phase electrical connection must be made by a registered electrical worker in line with local regulations, with proper earthing and overload and short-circuit protection.
- Check the rotation direction before first use; if it is wrong, have an electrician swap two phases.
- Lift the pump by its handle or a lifting chain. Never lift it by the power cable.
- Isolate and lock out the power before inspecting or clearing the suction cover. The tungsten carbide edges and serrated suction cover are sharp, so wear protective gloves.
- No explosion-proof rating is published; do not use the pump in flammable or explosive atmospheres.
- Sewage sumps are confined spaces with hydrogen sulfide and oxygen-deficiency hazards. A guide rail installation allows servicing without entering the sump.
- Tsurumi does not list this series for seawater, corrosive or chemical liquids, hot liquids or potable water; do not use it for these.
Wear parts and routine checks
- Main wear and consumable parts: tungsten carbide cutting edges on the impeller, suction cover, mechanical seals, oil seal and lubricating oil.
- The Oil Lifter only maintains lubrication down to about one third of the normal oil level, so check the oil level and condition regularly (ISO VG32, 500 ml). If the oil is cloudy or contains water, have the shaft seals inspected promptly.
- If flow drops or cutting performance falls off, isolate and lock out the power, then inspect the cutting edges and suction cover and clear any wrapped debris.
