The TSURUMI LB-800A (110V) is the single-phase 110V version of Tsurumi's LB-A series Portable Dewatering Pump (Automatic Operation type). It has a 50 mm (2-inch) discharge and a 0.75 kW 2-pole single-phase submersible motor. A built-in electrode-type level relay unit runs the pump while the probe is submerged, stops it about one minute after the water drops below the probe, and restarts it when the water reaches the probe again. The slim body fits inside an 8-inch pipe or well casing, and the pump is built for site water, seepage and rain water carrying a small amount of sand and silt.
This listing is the single-phase 110V build, suited to the 110V supply commonly used on Hong Kong construction sites. The 110V and 220V builds are different units and are not interchangeable. Check the voltage and frequency on the nameplate before use and make sure they match the supply (voltage within ±10% of the rated value).
Selection note: the LB-800A is a dewatering pump, not a sewage or slurry pump. It is for water, or water with a little sand and silt, and passes solids up to 6 mm, so it is not suitable for sewage with fibrous solids, septic tanks, sewage pits or slurry. It is controlled by electrodes and has no float switch. If you do not need automatic operation, choose the standard LB-800. If your site supply is not 110V, choose the non-110V LB-800A (voltage as per nameplate).
Key features
- Electrode auto-operation: the electrode level relay unit starts and stops the pump without a separate float switch, preventing dry-running and the on-off chattering caused by a turbulent water surface. Tsurumi states it can cut power use by up to 40% compared with non-automatic pumps (Tsurumi comparison). The relay is resin-molded inside a rubber case and has been jobsite tested for more than 30,000 on-off cycles.
- Top-discharge, flow-thru design: the design gives the motor maximum cooling, so the pump can run continuously at low water levels and has extended dry-run capability (Tsurumi does not publish a duration, so do not run it dry deliberately).
- Multi-directional hose coupling: the discharge can be set vertical or inclined so the hose does not fold. Loosen the cap nut on the coupling to change it.
- Dual inside mechanical seals: silicon carbide (SiC) faces in an oil chamber. Tsurumi states SiC offers five times the corrosion, wear and heat resistance of tungsten carbide.
- Tsurumi Oil Lifter: keeps the seal faces lubricated even when the oil drops to about one third of the normal level.
- V-ring dust seal: a nitrile (NBR) V-ring keeps abrasive particles away from the mechanical seal.
- Abrasion-resistant wear parts: semi-vortex urethane rubber impeller and synthetic rubber casing. Tsurumi rates their durability as equivalent to its three-phase drainage pumps.
- Built-in motor protector: a circle thermal protector (CTP) stops the motor on overheating or overcurrent, including overheating from dry-running, and resets automatically once cool.
- Anti-wicking cable entry: limits water creeping along the cable cores into the motor.
Applications
- Construction sites: dewatering of excavations, trenches and basement digs, with automatic start/stop by water level
- Basements: seepage and standing water removal
- Rain water and flooding: stormwater removal and emergency pumping
- Pipes and well casings: fits an 8-inch pipe or casing for well-point and deep-well dewatering
Performance
At 50 Hz, the 15.0 m maximum head is the head at near-zero flow, and the 0.31 m³/min (310 L/min, about 18.6 m³/h) maximum capacity is the end point of the performance curve. The two do not occur together: actual flow falls as total head (static head plus hose friction loss) rises, so select the pump from the performance curve using your site's total head. The 18.0 m maximum head quoted for 60 Hz builds does not apply on a 50 Hz supply. The LB-800A has the same pump performance as the standard LB-800. For a lighter pump at lower head, consider the LB-480A 110V (11.0 m maximum head).
Technical specifications
TSURUMI LB-800A (110V) technical specifications
| Item | Specification |
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| General |
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| Model | LB-800A (single-phase 110V build) |
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| Series | LB-A (Portable Dewatering Pump, Automatic Operation type) |
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| Discharge bore | 50 mm (2 in); 80 mm available on special request |
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| Discharge connection | Hose coupling (standard, vertical or inclined); male threaded pipe coupling on special request |
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| Hydraulic performance |
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| Max. head (at zero flow) | 15.0 m (50 Hz) / 18.0 m (60 Hz) |
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| Max. capacity (curve end point) | 0.31 m³/min (310 L/min / 18.6 m³/h) |
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| Solids passage | 6 mm |
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| Electrical |
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| Motor output | 0.75 kW |
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| Motor | 2-pole single-phase dry-type induction motor, continuous-duty rated, insulation class E |
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| Synchronous speed | 3,000 min⁻¹ (50 Hz) / 3,600 min⁻¹ (60 Hz) |
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| Power supply | Single-phase 110V (frequency as per nameplate) |
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| Voltage tolerance | ±10% of the nameplate rated voltage |
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| Starting method | Capacitor run |
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| Motor protection | Built-in circle thermal protector (CTP), auto-reset |
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| Cable | PVC, 5 m (Tsurumi global catalogue; lengths vary by regional build, check the unit supplied) |
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| Automatic operation |
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| Control | Electrode-type level relay unit (no float switch) |
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| Starting water level | 170 mm (can be lowered with optional extension probes) |
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| Stop | About 1 minute after the water falls below the probe |
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| Seals and bearings |
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| Shaft seal | Dual inside mechanical seals, silicon carbide (SiC) faces, oil-lubricated, with Oil Lifter |
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| V-ring | Nitrile butadiene rubber (NBR) |
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| Lubricant | Turbine oil ISO VG32, 155 ml |
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| Bearings | Shielded ball bearings |
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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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| Liquid limits |
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| Liquid | Water (may contain a little sand and silt), such as site water, seepage and rain water |
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| Liquid temperature | 0–40 °C |
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| pH | 5–9 |
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| Max. dry matter | 10% |
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| Max. use pressure | 0.2 MPa (about 20 m, submergence plus discharge pressure) |
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| Dimensions and weight |
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| Dry weight (excl. cable) | 13.7 kg |
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| Height | 341 mm |
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| Outer diameter (incl. level relay unit) | 223 mm |
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| Pipe / well casing fit | 8 in or larger |
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Sources: Tsurumi Single-phase Portable Pumps catalogue (IB101), Tsurumi LB series operation manual, tsurumi.com.hk and Tsurumi Europe LB series data. Tsurumi advises obtaining the delivery specification sheet before use, as published specifications may change. Voltage, frequency, cable length and rated current of the supplied unit are as per the nameplate.
LB series comparison
Tsurumi LB / LB-A series comparison (all 50 mm discharge, 50 Hz performance)
| Model | Operation | Power | Max. head | Max. capacity | Dry weight | Start / continuous running level |
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| LB-800A 110V (this product) / LB-800A | Automatic (electrode) | 0.75 kW | 15.0 m | 310 L/min | 13.7 kg | Start 170 mm |
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| LB-800 | Standard (manual) | 0.75 kW | 15.0 m | 310 L/min | 13.1 kg | Continuous 50 mm |
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| LB-480A / LB-480A 110V | Automatic (electrode) | 0.48 kW | 11.0 m | 220 L/min | 11 kg | Start 115 mm |
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| LB-480 / LB-480 110V | Standard (manual) | 0.48 kW | 11.0 m | 220 L/min | 10.4 kg | Continuous 50 mm |
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What's in the box
- LB-800A pump with cable and hose coupling × 1
- Hose band × 1
- Operation manual × 1
Optional accessories
- Extension probes × 2 (Tsurumi optional accessory): coil-spring type that can be cut to length to set a lower starting water level.
- 50 mm (2-inch) discharge hose: push it fully onto the hose coupling and secure it with the hose band.
- 80 mm discharge and male threaded pipe coupling: available from Tsurumi on special request.
- Earth leakage circuit breaker (ELCB) and thermal overload relay: purchased separately; set the overload relay to the nameplate rated current.
Safety and installation
- Electrical work must be carried out by a registered electrical worker to local regulations, with earthing, an ELCB and a thermal overload relay. Never connect the earth wire to a gas pipe, water pipe, lightning rod or telephone earth.
- Make sure the nameplate voltage and frequency match the supply. Never connect the 110V build to a 220V supply. When running from a generator, avoid powering other equipment from the same generator.
- Never lift, hang or drag the pump by the cable or the level relay unit. Use the handle with a rope or chain rated for the pump's weight. Do not scratch, fold, twist, modify or bundle the cable, and do not use a damaged cable, plug or outlet.
- Do not megger-test between the plug and the electrodes, or between the relay unit electrodes and the plug, as this damages the level relay.
- Never run the pump while anyone is in the sump or water, and never start it while it is suspended, as it may jerk.
- After a power cut, switch off the supply: the automatic pump restarts by itself when power returns. The motor protector also resets automatically, so disconnect power and remove the cause after a trip.
- Operate the pump upright. If it may draw in mud, stand it on a concrete block. Lay the discharge hose as straight as possible with its outlet above the water surface to avoid kinks, air lock and back-siphoning. Never run against a closed valve.
- Use for water at 0–40 °C only. Never pump oil, salt water or seawater, organic solvents or drinking water. The pump is neither explosion-proof nor dust-proof; do not use it where toxic, corrosive or explosive gas may be present.
- The surface gets hot during and right after operation, so do not touch it with bare hands. Switch off and unplug before inspection or maintenance, and never work with wet hands.
Wear parts and routine checks
- Daily: check operating current (within rated current) and supply voltage (within ±10% of rated voltage).
- Monthly: measure insulation resistance (1 MΩ minimum for a pump in service; 20 MΩ minimum for a new or repaired pump).
- Every 1,000 hours or 6 months, whichever comes first: inspect the oil. Milky oil or oil mixed with water points to a failed mechanical seal, and the pump must be disassembled and repaired.
- Every 2,000 hours or 12 months, whichever comes first: change the turbine oil ISO VG32 (155 ml). Replace the mechanical seal about yearly through the dealer or Tsurumi service.
- Replace the V-ring when worn and at each disassembly; replace packings and O-rings each time the pump is opened or inspected. Drawing in large amounts of mud accelerates wear of the impeller and other parts.
- For long storage, lift the pump out, wash and dry it, and keep it indoors. If it stays submerged, run it regularly (about once a week).
