The TSURUMI LB-480 is a portable dewatering pump from Tsurumi's LB series (officially classed under submersible pumps > dewatering > portable dewatering pumps). It has a 50 mm (2-inch) discharge, a 0.48 kW single-phase 2-pole motor and a dry weight of 10.4 kg. The slim body fits inside an 8-inch pipe or well casing, and the top-discharge, flow-thru design gives the motor maximum cooling so the pump can keep running at low water levels. It is built for site water containing sand and silt, seepage water and rain water.
Selection note: the LB-480 is a dewatering pump, not a sewage pump or a slurry pump. It is intended for water or water containing a little sand and silt (up to 10% dry matter, solids up to 6 mm), and is not suitable for sewage, liquids with fibrous solids or dense mud. The LB-480 is the standard, manually operated model. For automatic on/off operation, choose the LB-480A with electrode level control; for 110V site supplies, see the LB-480 110V version; for higher head, choose the LB-800; for settled sand and mud, choose the HSD2.55S slurry pump.
Key features
- Slim body: fits inside an 8-inch pipe or well casing, suiting well-point and deep-well dewatering as well as narrow sump pits.
- Top discharge with flow-thru design: water flows around the motor for maximum cooling, allowing continuous running at low water levels and extended dry-run capability. The continuous running water level is 50 mm; dry running should still be avoided.
- 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.
- Abrasion-resistant wear parts: a semi-vortex urethane rubber impeller and a synthetic rubber casing. Tsurumi rates the durability as equivalent to its three-phase drainage pumps.
- Dual inside mechanical seals: silicon carbide (SiC) faces running in an oil chamber, with Tsurumi's original Oil Lifter keeping the seal faces lubricated down to one third of the normal oil level. Tsurumi states that SiC offers five times the corrosion, wear and heat resistance of tungsten carbide.
- V-ring dust seal: a nitrile rubber (NBR) V-ring keeps abrasive particles away from the mechanical seal.
- Built-in miniature thermal protector (MTP): trips on motor overheating or overcurrent, including overheating from dry running, and resets automatically once the motor cools.
- Anti-wicking cable entry and cable clip: limit water creeping along the cable cores into the motor and protect the cable from tugging.
Applications
- Construction sites: excavations, sump pits and temporary standing water containing sand and silt
- Well-point and deep-well dewatering: pumping from inside an 8-inch pipe or well casing
- Basements and underground facilities: seepage water removal
- Storms: emergency removal of rain water
Performance
The 11 m maximum head (50 Hz) is the head at near-zero flow, and the 220 L/min (0.22 m³/min, about 13.2 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. Select the pump from the performance curve using your site's total head. For more head or flow, consider the LB-800 (15 m, 310 L/min).
Technical specifications
TSURUMI LB-480 technical specifications (50 Hz)
| Item | Specification |
|---|
| General |
|---|
| Model | LB-480 |
|---|
| Series | LB (standard, manual operation) |
|---|
| Type | Portable dewatering pump (submersible, single-phase) |
|---|
| Discharge bore | 50 mm (2 in) |
|---|
| Discharge connection | Multi-directional hose coupling (standard, vertical or inclined); male threaded coupling for pipe connection available on special order |
|---|
| Hydraulic performance |
|---|
| Max. head (at zero flow) | 11 m |
|---|
| Max. capacity (curve end point) | 220 L/min (0.22 m³/min / approx. 13.2 m³/h) |
|---|
| Max. solids size | 6 mm |
|---|
| Electrical |
|---|
| Motor output | 0.48 kW |
|---|
| Motor | Dry-type induction motor, 2-pole, insulation class E, continuous-duty rated |
|---|
| Synchronous speed | 3,000 min⁻¹ (50 Hz) |
|---|
| Power supply | Single-phase 50 Hz (voltage as per nameplate; supply within ±10% of rated voltage) |
|---|
| Starting method | Capacitor run |
|---|
| Motor protection | Built-in miniature thermal protector (MTP), automatic reset |
|---|
| Cable | PVC, 5 m |
|---|
| Seals and bearings |
|---|
| Shaft seal | Dual inside mechanical seals, silicon carbide (SiC) faces, oil-lubricated, with Oil Lifter |
|---|
| Lubricant | Turbine oil ISO VG32, 155 ml |
|---|
| V-ring | Nitrile rubber (NBR) |
|---|
| Bearings | Shielded ball bearings |
|---|
| Materials |
|---|
| Impeller | Semi-vortex, urethane rubber |
|---|
| Pump casing | Synthetic rubber |
|---|
| Shaft | 403 stainless steel |
|---|
| Liquid limits |
|---|
| Liquid | Water, or site water containing sand and silt, seepage water and rain water |
|---|
| Liquid temperature | 0–40 °C |
|---|
| pH | 5–9 (Tsurumi Europe data) |
|---|
| Max. dry matter | 10% (Tsurumi Europe data) |
|---|
| Max. use pressure | 0.2 MPa (approx. 20 m, including submergence and discharge pressure) |
|---|
| Dimensions and weight |
|---|
| Dry weight (excl. cable) | 10.4 kg |
|---|
| Height | 286 mm |
|---|
| Installation space | Fits inside an 8-inch pipe or well casing |
|---|
| Continuous running water level | 50 mm |
|---|
Sources: Tsurumi single-phase portable pumps catalogue (IB101), the Tsurumi LB series operation manual, and Tsurumi Hong Kong and Tsurumi Europe LB series data (50 Hz). Tsurumi notes that published data may differ from the actual product, so request the delivery specification sheet before use. Voltage and rated current are as per the nameplate.
LB series comparison
Tsurumi LB series portable dewatering pump comparison (50 Hz)
| Model | Operation | Discharge | Power | Max. head | Max. capacity | Dry weight |
|---|
| LB-480 (this product) | Standard (manual) | 50 mm | 0.48 kW | 11 m | 220 L/min | 10.4 kg |
|---|
| LB-480A | Automatic (electrode) | 50 mm | 0.48 kW | 11 m | 220 L/min | 11 kg |
|---|
| LB-800 | Standard (manual) | 50 mm | 0.75 kW | 15 m | 310 L/min | 13.1 kg |
|---|
| LB-800A | Automatic (electrode) | 50 mm | 0.75 kW | 15 m | 310 L/min | 13.7 kg |
|---|
110V versions: LB-480 110V, LB-480A 110V, LB-800A 110V.
What's in the box
- LB-480 pump with attached cable and hose coupling × 1
- Hose band × 1
- Operation manual × 1
Optional accessories
- 50 mm (2-inch) discharge hose, secured with the supplied hose band. Push the hose fully onto the coupling.
- Male threaded coupling for pipe connection (special order).
- External float switch to add automatic operation to the standard LB-480, or choose the LB-480A with built-in electrode level control.
- Earth leakage circuit breaker (ELCB) and thermal overload relay set to the rated current, purchased separately.
Safety and installation
- Electrical work must be carried out by a registered electrical worker in line with local regulations. Always provide earthing, an ELCB and a thermal overload relay. Never connect the earth wire to a gas pipe, water pipe, lightning rod or telephone earth.
- Check that the nameplate voltage and frequency match the supply, and keep the supply within ±10% of the rated voltage. The 110V and 220V versions are different builds and are not interchangeable. When running from a generator, avoid powering other equipment from the same generator.
- Never lift, suspend or pull the pump by the cable; use the handle with a rope or chain rated for the pump weight. Do not scratch, fold, twist, modify or bundle the cable, and do not use a damaged cable, plug or outlet.
- Operate the pump upright. If it may draw in mud, stand it on a concrete block. Run the discharge hose as straight as possible with its outlet above the water surface to avoid kinks, air lock and backflow.
- Do not run the pump dry or against a closed valve, at abnormally low head or with a clogged impeller. The motor protector resets automatically after a trip, so switch off the power and remove the cause first. After a power cut, switch off the supply, or the pump will restart when power returns.
- Never run the pump while anyone is in the water or sump, and never start it while it is suspended, as it may jerk.
- For water only, 0–40 °C. Do not use for seawater, oil, organic solvents or potable water. The pump is not explosion-proof or dust-proof; do not use it where toxic, corrosive or explosive gases may be present.
- The surface gets hot during and just after operation; do not touch it with bare hands. Switch off and unplug before any inspection or maintenance, and never work with wet hands.
Wear parts and routine checks
- Main wear parts: the impeller, pump casing and other parts in contact with sand, plus the mechanical seals and V-ring. Drawing in large amounts of mud speeds up wear and reduces flow.
- Motor insulation resistance must be at least 20 MΩ on a new or repaired pump.
- Measure the motor insulation resistance monthly (reference value 1 MΩ minimum); if it has dropped considerably since the last check, have the motor inspected.
- Inspect the oil every 1,000 hours or 6 months, and change it every 2,000 hours or 12 months, whichever comes first (non-additive turbine oil ISO VG32, 155 ml). Milky oil or oil mixed with water usually points to a failed mechanical seal, and the pump must be disassembled and repaired.
