The TSURUMI LSP1.4S is a single-phase, portable self-priming residue drainage pump (classed by Tsurumi Hong Kong under surface construction dewatering pumps > self-priming residue dewatering pump). It has 25 mm suction and discharge ports and a 0.48 kW single-phase capacitor-run motor. A suction attachment comes as standard and draws floor water down to near floor level, while a built-in siphon-break mechanism prevents backflow and loss of priming water when the pump stops. Its main parts are aluminium alloy and synthetic rubber, keeping the dry weight to 16.5 kg so the pump is easy to carry. Because it uses a submersible motor, it keeps running even if the whole unit ends up under water.
Selection note: the LSP1.4S sits out of the water and draws through a suction attachment and suction hose. This sets it apart from the submersible LSC1.4S residue drainage pump, which runs submerged in the water. The LSP1.4S reaches a maximum head of 6.9 m (50 Hz), against 11 m (50 Hz) for the LSC1.4S. If the pump can be placed directly in the water and you need more head, consider the LSC series. Both need priming water: the LSP1.4S takes about 1.8 L before every start, and the LSC1.4S about 2.5 L at first start or when the water level is low.
Key features
- Self-priming with a standard suction attachment: the free-positioning suction attachment draws floor water down to near floor level, with a maximum vacuum of -73.3 kPa (-550 mmHg).
- Built-in submersible motor: the pump is used on the surface, but the submersible motor runs normally even if the entire unit is submerged.
- Siphon-break and backflow prevention: stops pumped water flowing back and prevents loss of priming water when the pump stops.
- Light and durable: aluminium alloy and synthetic rubber main parts keep the dry weight to 16.5 kg, and the rubber base protects floors.
- Top-discharge flow-thru design: gives maximum motor cooling and improves dry-running tolerance. The pump must still never be run dry.
- Double inside mechanical seals: silicon carbide (SiC) faces housed in an oil chamber, with Tsurumi's Oil Lifter to keep the seals lubricated when the oil level drops, plus a V-ring dust seal.
- Anti-wicking cable entry: limits water creeping along the cable cores into the motor if the cable sheath is damaged.
- Built-in miniature thermal protector (MTP): cuts power automatically on overheating or overload.
Applications
- Construction sites: removing standing and residual water from floor slabs
- Factories: drainage around equipment
- Water tanks and cisterns: emptying residual water from the tank floor
For clean-water-type liquids only, at 0–40 °C. Not for slurry, sandy water, seawater, brine, oil, chemicals or organic solvents, and not for use in flammable or explosive atmospheres.
Performance
The maximum head of 6.9 m (50 Hz) / 7.8 m (60 Hz) is the head at near-zero flow, and the maximum capacity of 50 L/min (50 Hz) / 55 L/min (60 Hz) is the end point of the performance curve. The two do not occur together: actual flow falls as total head (discharge height plus hose friction loss) rises. Select the pump from the performance curve using your site's total head. Hong Kong mains is 50 Hz, so use the 50 Hz figures.
Technical specifications
TSURUMI LSP1.4S technical specifications (50 Hz / 60 Hz)
| Item | Specification |
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| General |
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| Model | LSP1.4S |
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| Type | Single-phase portable self-priming residue drainage pump |
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| Suction × discharge bore | 25 × 25 mm |
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| Connections | Hose couplings |
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| Hydraulic performance |
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| Max. head (at zero flow) | 6.9 m (50 Hz) / 7.8 m (60 Hz) |
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| Max. capacity (curve end point) | 50 L/min (50 Hz) / 55 L/min (60 Hz) |
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| Max. vacuum | -73.3 kPa (-550 mmHg) |
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| Priming water | Approx. 1.8 L before every start |
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| Electrical |
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| Motor output | 0.48 kW (2/3 HP) |
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| Motor | Dry-type submersible induction motor, continuous rating, 2-pole, insulation class E |
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| Power supply | Single-phase (voltage as per nameplate) |
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| Starting method | Capacitor run |
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| Motor protection | Built-in miniature thermal protector (MTP) |
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| Cable | PVC cable, 5 m |
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| Seals and lubrication |
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| Shaft seal | Double inside mechanical seals, silicon carbide (SiC) faces, with Oil Lifter |
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| Dust seal | V-ring |
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| Lubricant | Turbine oil ISO VG32, 150 ml |
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| Materials |
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| Impeller | Semi-vortex, urethane rubber |
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| Pump casing | Synthetic rubber |
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| Shaft | 403 stainless steel |
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| Main parts | Aluminium alloy and synthetic rubber |
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| Liquid limits |
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| Liquid | Clean-water-type standing and residual water |
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| Liquid temperature | 0–40 °C |
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| Max. allowable water pressure | 0.2 MPa |
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| Solids passage | No official rating (not for liquids containing solids) |
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| Dimensions and weight |
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| Dry weight (excl. cable) | 16.5 kg |
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| Height | 307 mm |
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| Suction attachment diameter | φ140 mm |
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Sources: Tsurumi LB/HS/NK/LSC/LSP series catalogue (IB101), the Tsurumi Hong Kong LSP product page and Tsurumi Japan's technical handbook. Voltage and rated current of the Hong Kong supply version are as per the nameplate.
Tsurumi residue drainage pump comparison
Tsurumi LSP / LSC residue drainage pump comparison
| Model | Type | Discharge | Power | Max. head | Priming |
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| LSP1.4S (this product) | Surface self-priming (with suction attachment) | 25 mm | 0.48 kW | 6.9 m (50 Hz) / 7.8 m (60 Hz) | Approx. 1.8 L before every start |
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| LSC1.4S | Submersible, drains to approx. 1 mm | 25 mm | 0.48 kW | 11 m (50 Hz) / 12 m (60 Hz) | Approx. 2.5 L at first start or low water |
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| LSCE1.4S | Submersible, electrode automatic | 25 mm | 0.48 kW | 11 m (50 Hz) / 12 m (60 Hz) | Approx. 2.5 L at first start |
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| LSC2.75S | Submersible, drains to approx. 1 mm | 50 mm | 0.75 kW | 17 m (60 Hz) | Casing must be wet to start |
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What's in the box
Standard accessories for the LSP, as listed in Tsurumi's operation manual:
- LSP1.4S pump with 5 m cable × 1
- φ25 mm union hose coupling with hose band × 1 set
- Suction hose with union (5 m, fittings on both ends) × 1 set
- Suction attachment × 1 set
- Operation manual × 1
Optional accessories
- Extension cable: the conductor cross-section must not be smaller than the original cable. Please contact us before extending the cable.
- Earth-leakage circuit breaker: the pump must be used with earth-leakage protection.
Safety and installation
- Before every start, remove the priming plug and fill with about 1.8 L of clean water. Never run the pump dry or against a closed valve.
- Supply voltage must stay within ±10% of the rating. A 50 Hz pump must not be run on 60 Hz, or vice versa. When powering from a generator, do not connect other equipment at the same time.
- Earth the pump properly and use it with an earth-leakage circuit breaker. Never connect the earth wire to a gas pipe, water pipe, lightning rod or telephone earth.
- Carry the pump by its handle. Never lift or pull it by the cable. Do not kink or sharply bend the cable, do not submerge a damaged cable, and keep cable joints and plugs dry.
- The pump body is hot during and just after operation; avoid touching it. Take care when opening the priming plug, as hot water may spray out.
- If the motor protector trips, find and fix the cause before restarting. Switch off and unplug the pump before inspection or servicing, and do not stand next to the pump while it is running.
Wear parts and routine checks
- Measure insulation resistance and check running current and voltage monthly.
- Change the lubricating oil (turbine oil ISO VG32) periodically and check the condition of the check valve.
- An overhaul is recommended every 2–5 years. Mechanical seal replacement must be carried out by the agent.
