The TSURUMI 50NHC22.2 is a submersible cutter sewage pump from Tsurumi's NHC series (TSURUMI UNIVERSE brand, officially a non-clogging cutter-type sewage pump). It has a 50 mm discharge and a 2.2 kW 2-pole three-phase dry-type induction motor running at about 3,000 min⁻¹ on 50 Hz. Two sintered tungsten carbide alloy edges are brazed onto the impeller vanes and rotate against the serrated suction cover, cutting rags and fibrous material into pieces so they pass through instead of clogging the pump, discharge pipe or valves. It is built for raw sewage, wastewater and heavy-duty industrial duties where oversize material would otherwise block a pump.
Selection note: the 50NHC22.2 and the 80NHC22.2 share the same 2.2 kW motor but differ in discharge size and duty. The 50NHC22.2 has the higher shut-off head (approx. 23.5 m vs approx. 22 m), while the 80NHC22.2 reaches more flow at the end of its curve (approx. 0.67 m³/min vs approx. 0.55 m³/min). Choose the 50NHC22.2 for higher-head, lower-flow lines and the 80NHC22.2 when you need more volume. Note that the NHC is a sewage cutter pump, not a slurry pump: it is not suitable for sand slurry, abrasive slurry or site mud.
Key features
- Cutter impeller: semi-open two-channel impeller with two sintered tungsten carbide edges brazed onto the vanes, working against a serrated suction cover to shred fibrous material and prevent clogging in discharge pipes and valves.
- Double inside mechanical seals: silicon carbide (SiC) faces housed in an oil chamber. Tsurumi rates SiC at five times the corrosion, wear and heat resistance of tungsten carbide.
- Oil Lifter (Tsurumi original design): keeps the seal faces lubricated and cooled even when the oil level falls to about one third of normal.
- Built-in circle thermal protector (CTP): directly cuts the motor circuit on excessive heat or overcurrent.
- Class H insulated motor: continuous-duty dry-type induction motor, direct-on-line (D.O.L.) start.
- Anti-wicking cable entry: limits water creeping along the cable cores into the motor.
- Guide rail option (TOS50NHC22.2): raise and lower the pump along guide pipes for maintenance without anyone entering the sump.
Applications
- Septic and purifying tanks: raw water transfer
- Wastewater treatment facilities: sewage and wastewater transfer
- Pumping stations: lifting sewage that carries fibrous debris
- Flood prevention equipment
- Reservoirs at recreational facilities
- Sewage and wastewater drainage: sumps prone to clogging from rags and fibres
Performance
On Tsurumi's 50 Hz performance curve, the 50NHC22.2 has a shut-off head (maximum head, at near-zero flow) of approx. 23.5 m. The curve ends at approx. 0.55 m³/min (about 550 L/min or 33 m³/h) at approx. 12.8 m head. The two never occur together: flow falls as total head (static head plus pipe friction loss) rises, so select from the curve using your system's total head. These are approximate curve readings, not guaranteed duty points. Tsurumi advises against continuous operation on the dashed (low-flow) section of the curve. For more head, consider the 50NHC23.0 or 50NHC23.7 (shut-off head approx. 31.5–32 m).
Technical specifications
TSURUMI 50NHC22.2 technical specifications (50 Hz)
| Item | Specification |
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| General |
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| Model | 50NHC22.2 |
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| Series | NHC (submersible sewage pump, cutter impeller, 2-pole) |
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| Discharge bore | 50 mm |
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| Discharge connection | Threaded JIS 10kg/cm² flange |
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| Guide rail model | TOS50NHC22.2 (sold separately) |
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| Hydraulic performance (approximate curve readings) |
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| Max. head (at zero flow) | approx. 23.5 m |
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| Max. capacity (curve end point) | approx. 0.55 m³/min (at approx. 12.8 m) |
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| Electrical |
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| Motor output | 2.2 kW |
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| Motor | 2-pole dry-type induction motor, continuous duty, insulation class H |
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| Speed | 3,000 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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| Cable | 6 m, chloroprene rubber |
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| Seals and lubrication |
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| Shaft seal | Double inside mechanical seals, silicon carbide (SiC) faces, in oil chamber, with Oil Lifter |
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| Oil seal | NBR |
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| Lubricant | Turbine oil ISO VG32, 1,160 ml |
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| Materials |
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| Impeller | Grey cast iron with tungsten carbide alloy edges |
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| Suction cover | Ductile cast iron |
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| Pump casing | Grey cast iron |
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| Motor frame | Grey cast iron |
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| Shaft | 420 stainless steel |
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| Dimensions and weight |
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| Dimensions (L × W × H), free-standing | 454 × 238 × 510 mm |
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| Dimensions (L × W × H), guide rail fitting | 637 × 238 × 569 mm |
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| Dry weight, free-standing (excl. cable) | 44 kg |
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| Dry weight, guide rail fitting (excl. cable and duckfoot bend) | 39 kg |
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Sources: TSURUMI UNIVERSE NH-series submersible sewage pump catalogue (IA143, 50 Hz) and TSURUMI UNIVERSE NHC product data. Tsurumi notes that catalogue specifications may change without notice; obtain the factory specification sheet before use. Maximum liquid temperature, maximum solids passage, pH range and rated current are not published; voltage and current of the Hong Kong supply version are as per the nameplate.
NHC series comparison
Tsurumi NHC series model comparison (50 Hz, approximate curve readings)
| Model | Discharge | Power | Max. head (zero flow) | Max. capacity (curve end) |
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| 50NHC2.75 | 50 mm | 0.75 kW | approx. 16 m | approx. 0.30 m³/min |
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| 50NHC21.5 | 50 mm | 1.5 kW | approx. 19.5 m | approx. 0.43 m³/min |
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| 50NHC22.2 (this product) | 50 mm | 2.2 kW | approx. 23.5 m | approx. 0.55 m³/min |
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| 50NHC23.0 | 50 mm | 3.0 kW | approx. 31.5–32 m | approx. 0.50 m³/min |
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| 50NHC23.7 | 50 mm | 3.7 kW | approx. 31.5–32 m | approx. 0.67 m³/min |
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| 80NHC22.2 | 80 mm | 2.2 kW | approx. 22 m | approx. 0.67 m³/min |
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| 80NHC23.0 | 80 mm | 3.0 kW | approx. 16.7 m | approx. 1.25 m³/min |
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| 80NHC23.7 | 80 mm | 3.7 kW | approx. 28 m | approx. 1.0 m³/min |
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| 80NHC211 | 80 mm | 11 kW | approx. 49 m | approx. 0.99 m³/min |
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Optional accessories
- Guide rail fitting TOS50NHC22.2: cast-iron guide rail system, ordered as the TOS model. The 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. Guide pipes are not supplied and must be sourced locally.
- Discharge flange and fittings: the pump has a threaded JIS 10kg/cm² flange, so mating flanges and fittings must be JIS 10K.
- Float switches (level sensors): MC-2 heavy-duty float with shock absorber for liquids with much suspended solids and scum, NO or NC contact selectable; MT-1 economy teardrop float for scum-laden wastewater, SPDT contact for filling or emptying control.
- Control panel: this model is D.O.L. started and its built-in CTP cuts the motor circuit directly; pair it with float switches and a control panel for automatic level control.
- Lubricant: turbine oil ISO VG32, 1,160 ml per oil change.
Safety and installation
The first two points are from Tsurumi's catalogue; the rest are general installation guidance:
- Do not run the pump continuously on the dashed (low-flow) section of the performance curve.
- The Oil Lifter keeps the seals lubricated only down to about one third of the normal oil level, so regular oil checks are still required.
- Three-phase connection must be made by a registered electrical worker, 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 lifting chain, never 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.
- No explosion-proof rating is published; do not use in flammable or explosive atmospheres.
- Sewage sumps are confined spaces with hydrogen sulphide and oxygen-deficiency hazards. A guide rail fitting lets the pump be lifted out for service without entering the sump.
- Liquid temperature, pH and solids-size limits are not published; check with your supplier before pumping chemicals, seawater or hot liquids.
Wear parts and routine checks
- The tungsten carbide edges, serrated suction cover and mechanical seals are the main wearing parts. If cutting performance falls, flow drops or clogging becomes frequent, have the impeller and suction cover inspected.
- Check the oil level and condition in the oil chamber regularly (turbine oil ISO VG32, 1,160 ml). If the oil is cloudy or contains water, have the shaft seals inspected promptly.
