The TSURUMI KRS611 is a heavy-duty submersible dewatering pump from Tsurumi's KRS series (officially classed as a general construction pump). It has a 150 mm (6-inch) discharge and an 11 kW 4-pole three-phase motor. With a semi-open ductile-iron impeller, a grey cast-iron body and a low-speed motor, it is built for drainage jobs that need both good head and high volume, such as excavations, tunnels and storm flooding. It handles stormwater, groundwater, wash water and sand-carrying site water (up to 15% dry matter, pH 5–9, solids up to 20 mm).
Selection note: the KRS611 is a dewatering pump, not a slurry pump. It has no agitator and no high-chrome wear parts, so it is not suitable for settled sludge, dense sand slurry, desilting or dredging. For that duty, choose the KRD611 or KRS-200 slurry pumps, which have a high-chrome impeller and an agitator. Also note that the KRS811, another 11 kW model, has a 200 mm discharge, passes 30 mm solids and delivers more flow, while the KRS611 has a 150 mm discharge and develops more head.
Key features
- Top-discharge, side-flow design: the motor stays cooled even when it runs exposed to air, and the slim body fits confined spaces. Keep at least 180 mm of water (50 Hz) for continuous running and do not run it dry for long periods.
- Double inside mechanical seals: silicon carbide faces on both the upper and lower seals (SiC/SiC), housed in an isolated oil chamber. Tsurumi's original Oil Lifter keeps the seal faces lubricated and cooled even when the oil drops to about one third of the normal level.
- Lip-type oil seal (dust seal): a nitrile rubber seal shields the mechanical seal from abrasive particles.
- Built-in circle thermal protector (CTP): cuts the motor circuit directly on excessive heat or overcurrent.
- Anti-wicking cable entry: blocks water from wicking along the cable cores into the motor if the sheath is damaged or the cable end is submerged; a cable clip provides strain relief.
- Low-speed 4-pole motor: continuous-duty dry-type induction motor, IP68, insulation class F, 1,500 min⁻¹ synchronous speed at 50 Hz, paired with a cast-iron body for long service life.
- Starting: direct-on-line (DOL) as standard, star-delta on special request; also suitable for soft starters and variable-frequency drives (VFD).
- 20 mm solids passage: suited to sandy site water.
Applications
- Construction and civil engineering: excavation and basement dewatering, temporary site drainage
- Tunnels, bridges and dams: removal of seepage and standing water during works
- Provisional sewage drainage: temporary drainage during construction
- Storms and flooding: emergency rainwater and flood drainage, boosting flood pumping stations
- Reservoirs and shipyards: reservoir drainage and dry-dock drainage
Performance
Tsurumi's catalogue does not list exact maximum head and capacity figures for the KRS611. Read from Tsurumi's official 50 Hz performance curve, the maximum head is about 22 m, which is the head at near-zero flow, and the maximum capacity is about 3.65 m³/min (about 3,650 L/min), which is the end point of the curve at roughly 2.5 m head. The two do not occur together: actual flow falls as total head (static head plus hose friction loss) rises. These are approximate curve readings, so select the pump from the official curve using your site's total head. For more flow, consider the 200 mm KRS811 (5,500 L/min) or KRS815 (6,400 L/min).
Technical specifications
TSURUMI KRS611 technical specifications (50 Hz)
| Item | Specification |
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| General |
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| Model | KRS611 (North American model KRS2-B6) |
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| Series | KRS (general construction pump, heavy-duty submersible dewatering) |
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| Discharge bore | 150 mm (6 in) |
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| Discharge connection | Hose coupling (standard); male threaded coupling optional |
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| Hydraulic performance |
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| Max. head (at zero flow) | approx. 22 m (read from official curve) |
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| Max. capacity (curve end point) | approx. 3.65 m³/min (approx. 3,650 L/min, read from official curve) |
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| Max. solids size | 20 mm |
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| Electrical |
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| Motor output | 11 kW |
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| Motor | 4-pole dry-type induction motor, continuous duty, IP68, insulation class F |
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| Speed | 1,500 min⁻¹ synchronous (50 Hz) |
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| Power supply | 3-phase 50 Hz (voltage as per nameplate) |
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| Rated current | As per nameplate (Tsurumi rating at 380 V 50 Hz: 23.0 A) |
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| Starting method | Direct-on-line (DOL); star-delta on special request; suitable for soft starters and VFDs |
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| Motor protection | Built-in circle thermal protector (CTP) |
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| Cable | 8 m standard, chloroprene rubber sheath, anti-wicking cable entry |
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| Seals and bearings |
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| Shaft seal | Double inside mechanical seals, SiC/SiC faces upper and lower, isolated oil chamber, with Oil Lifter |
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| Oil seal | Nitrile rubber lip seal (dust seal) |
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| Lubricant | Turbine oil ISO VG32, 2,300 ml |
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| Bearings | Double-shielded deep-groove ball bearings (C3, permanently lubricated) |
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| Materials |
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| Impeller | Semi-open, ductile cast iron |
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| Suction cover, casing, motor frame | Grey cast iron |
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| Shaft | 420 stainless steel |
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| Liquid limits |
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| Liquid | Stormwater, groundwater, wash water and sand-carrying water |
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| Liquid temperature | 0–40 °C |
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| pH | 5–9 |
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| Max. dry matter | 15% |
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| Max. submersion depth | 40 m |
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| Dimensions and weight |
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| Dry weight (excl. cable) | 163 kg |
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| Dimensions (L × W × H) | 436 × 407 × 875 mm |
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| Min. water level for continuous running | 180 mm |
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Sources: Tsurumi KRS/KRD series catalogue (IB111) and Tsurumi KRS model specification sheets (50 Hz). Voltage, cable and rated current of the Hong Kong supply version are as per the nameplate and confirmation from the Hong Kong agent.
KRS series comparison: 100–200 mm
Tsurumi KRS series model comparison (50 Hz)
| Model | Discharge | Power | Max. head | Max. capacity | Max. solids |
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| KRS45.5 | 100 mm | 5.5 kW | approx. 20 m | approx. 2,000 L/min | 12 mm |
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| KRS67.5 | 150 mm | 7.5 kW | approx. 19 m | approx. 2,850 L/min | 20 mm |
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| KRS611 (this product) | 150 mm | 11 kW | approx. 22 m | approx. 3,650 L/min | 20 mm |
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| KRS811 | 200 mm | 11 kW | 17.5 m | 5,500 L/min | 30 mm |
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| KRS815 | 200 mm | 15 kW | 21.5 m | 6,400 L/min | 25 mm |
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Values marked "approx." are read from Tsurumi's official 50 Hz performance curves; Tsurumi's catalogue does not list exact figures for these models.
What's in the box
- KRS611 pump with attached cable × 1
- Hose coupling × 1
Optional accessories
- Male threaded discharge coupling (Tsurumi option, replaces the standard hose coupling).
- 150 mm (6-inch) discharge hose.
- Float switch. On a three-phase pump it must switch a control-panel contactor, never the motor directly.
- Motor overload protector or control panel, set to the nameplate rated current.
Safety and installation
- The pump weighs about 163 kg dry. Lift it by its handle with a chain or shackle rated for the load. Never lift it by the cable or the hose.
- Electrical connection must be made by a registered electrical worker in line with the Hong Kong wiring regulations, with earth-leakage protection. Set the overload relay to the nameplate rated current. An 11 kW direct-on-line start needs adequately sized cable, breaker and generator capacity.
- Check rotation before first use: at start-up the pump body should kick anticlockwise when viewed from above. If it turns the wrong way, have an electrician swap two phases. Do not hold the handle while checking.
- After the built-in motor protector trips, the motor restarts automatically once it cools. Always isolate and lock off the power before inspection or servicing.
- Stand the pump on a firm or raised base so it does not sink into silt. Do not run continuously below 180 mm of water, and avoid prolonged dry running.
- The standard model is not seawater-resistant and is not for seawater or brackish water. Do not pump liquids outside pH 5–9, flammable liquids, oils or chemicals. Liquids above 40 °C require Tsurumi's special high-temperature build.
Wear parts and routine checks
- Main wear parts: impeller, suction cover, mechanical seals and oil seal. With long running in sandy water, the impeller and suction cover gradually wear and flow drops.
- Regularly check the oil in the oil chamber (turbine oil ISO VG32, 2,300 ml) and the clearance between the impeller and the suction cover. If the oil is milky, cloudy or contains water, have the shaft seals inspected promptly.
