The TSURUMI HSR2.4S is a single-phase portable submersible pump from Tsurumi's HS series, officially classed as a residue dewatering pump. It has a 50 mm discharge, a 0.4 kW capacitor-run single-phase motor and a urethane-rubber semi-vortex impeller. It starts pumping once there is 5 mm or more of water and keeps going until the level is down to 1 mm, which makes it the tool for clearing the last shallow water from basements, plant rooms, lift pits and site floors.
A rubber stand protects the floor from scratching, and the wear-prone parts are made of abrasion-resistant material, giving what Tsurumi describes as durability equivalent to a three-phase drainage pump. The side discharge has a multi-directional hose coupling that can point vertically or at an angle, so the hose does not kink.
Selection note: the HSR2.4S is built to pump down to a very low level. Its solids passage is only 3 mm and it has no agitator, so it is not suitable for slurry, settled sand or water carrying larger particles. For general site dewatering, choose the HS2.4S portable dewatering pump (7 mm solids, 90 mm continuous running level). For automatic float-switch operation, choose the HSZ2.4S. For muddy water, use the HSD2.55S slurry pump.
Key features
- Very low water level drainage: starts pumping at 5 mm of water or more and keeps pumping down to 1 mm.
- Rubber stand: protects finished floors from scratching, well suited to indoor work.
- Multi-directional hose coupling: vertical or inclined discharge to avoid kinking the hose.
- Dual inside mechanical seals: silicon carbide (SiC) faces running in an oil chamber, with Tsurumi's own Oil Lifter, which keeps the seal faces lubricated and cooled even when the oil drops to about one third of the normal level.
- Built-in miniature thermal protector (MTP): detects motor overheating and protects against overheating and dry running.
- Anti-wicking cable entry: stops water creeping into the motor by capillary action if the cable sheath is damaged or the cable end is submerged, and prevents condensation inside the motor housing. A cable clip protects against tugging.
- Wear-resistant build: abrasion-resistant wear parts for durability comparable to three-phase drainage pumps.
- Light and portable: 10.8 kg dry weight (excluding cable) and a single-phase supply, easy for one person to carry.
Applications
- Basements, car parks and plant rooms: clearing residual surface water
- Lift pits and sumps: final shallow-water clean-up
- Construction sites: shallow water on slabs, podiums and excavation floors
- After floods and storms: clearing standing water indoors and outdoors
- Mosquito control: removing standing water where mosquitoes breed
Performance
Tsurumi publishes only a performance curve for the HSR2.4S, with no official maximum head or maximum capacity figures; the curve was measured with the pump hanging and nothing restricting the suction. In general, maximum head is the head at near-zero flow and maximum capacity is the end point of the curve. The two never occur together: actual flow falls as total head (static head plus hose friction loss) rises. Select the pump from Tsurumi's official curve using your site's total head, or ask us for the delivery specification sheet. If you need more volume and do not need to pump down to a very low level, consider the HS2.4S (12 m max. head, 200 L/min max. capacity).
Technical specifications
TSURUMI HSR2.4S technical specifications (50 Hz)
| Item | Specification |
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| General |
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| Model | HSR2.4S |
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| Series / type | HS series, residue dewatering pump (single-phase portable submersible) |
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| Discharge bore | 50 mm (2 in) |
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| Discharge connection | Multi-directional hose coupling (vertical or inclined); male threaded coupling for pipe available on special request |
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| Hydraulic performance |
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| Start-up water level | 5 mm or more |
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| Lowest pump-down level | 1 mm |
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| Solids passage | 3 mm |
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| Head and capacity | See Tsurumi's official performance curve (measured hanging, no suction restriction) |
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| Electrical |
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| Motor output | 0.4 kW |
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| Motor | Dry-type induction motor, 2-pole, insulation class E, continuous-duty rated |
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| Synchronous speed | 3,000 min⁻¹ (50 Hz) |
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| Power supply | Single-phase 50 Hz (voltage as per nameplate) |
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| Starting method | Capacitor run |
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| Motor protection | Built-in miniature thermal protector (MTP), overheat and dry-run protection |
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| Seals and cable |
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| Shaft seal | Dual inside mechanical seals, silicon carbide (SiC) faces, oil-lubricated, with Oil Lifter |
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| Lubricant | Turbine oil ISO VG32, 160 ml |
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| V-ring | Not fitted |
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| Cable | 5 m PVC cable, anti-wicking cable entry, cable clip |
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| Materials |
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| Impeller | Semi-vortex, urethane rubber |
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| Pump casing | Ductile cast iron |
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| Shaft | 403 stainless steel |
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| Agitator | Not fitted |
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| Stand | Rubber stand |
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| Dimensions and weight |
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| Dry weight (excl. cable) | 10.8 kg |
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| Dimensions (L × W × H) | 271 mm (body 227 mm) × 162 mm × 282 mm |
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| Discharge centre height | 112 mm |
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Sources: Tsurumi single-phase portable pumps catalogue (IB101) and the Tsurumi Hong Kong and global HSR product pages. Tsurumi notes that website data may differ from the actual product, so obtain the delivery specification sheet before use. Voltage and rated current of the Hong Kong supply version are as per the nameplate.
HS series 50 mm single-phase model comparison
Tsurumi HS series 50 mm single-phase models (50 Hz)
| Model | Official type | Power | Solids | Max. head | Max. capacity | Water level |
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| HSR2.4S (this product) | Residue dewatering pump | 0.4 kW | 3 mm | See curve | See curve | Starts at 5 mm, pumps down to 1 mm |
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| HS2.4S | Portable dewatering pump | 0.4 kW | 7 mm | 12 m | 200 L/min | 90 mm continuous running |
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| HSZ2.4S | Portable dewatering pump (automatic) | 0.4 kW | 7 mm | 12 m | 200 L/min | Float switch start/stop |
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| HS2.75S | Portable dewatering pump | 0.75 kW | 7 mm | 18 m | 230 L/min | 90 mm continuous running |
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| HSD2.55S | Slurry pump | 0.55 kW | 9 mm | 13.2 m | 220 L/min | 105 mm continuous running |
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Optional accessories
- 50 mm (2 in) discharge hose for the standard hose coupling.
- Male threaded coupling for pipe connection (special order).
- Power outlet with earth-leakage (RCD) protection (recommended).
Safety and installation
- Connect only to a correctly earthed single-phase 50 Hz supply of matching voltage (as per the nameplate). An RCD-protected outlet is recommended. Any fixed wiring must be done by a registered electrical worker in line with local regulations.
- Carry and lower the pump by its handle. Never pull or lift it by the cable. Protect the cable from damage and have a damaged cable replaced or repaired promptly.
- The built-in MTP is a safeguard only. Switch the pump off once the water is cleared and do not let it run dry for long periods.
- Stand the pump level on firm ground. The HSR2.4S has no agitator and only a 3 mm solids passage, so keep sand, debris and loose objects away from the suction.
- Do not use in flammable or explosive atmospheres, and do not pump flammable, corrosive or hot liquids. The pump is not designed for seawater.
Wear parts and routine checks
- Main wear parts: urethane-rubber impeller and mechanical seals.
- Always isolate the power before inspection or servicing.
- Check and change the seal oil (turbine oil ISO VG32, 160 ml) regularly. If the oil is cloudy or contains water, have the shaft seals inspected promptly. The Oil Lifter only maintains lubrication down to about one third of the oil level and is no substitute for regular oil changes.
- Regularly check the suction and the rubber stand, clear any blockage and replace damaged parts.
