The TSURUMI HSZ3.75SL 110V is the automatic version of Tsurumi's high-volume, low-head portable dewatering pump in the HS series. It has an 80 mm (3-inch) discharge and a 0.75 kW single-phase motor, and this unit is the single-phase 110V 50Hz version for sites powered from a 110V site transformer. A single float switch starts the pump when the water rises to a preset level and stops it when the level falls, so it can run unattended without dry-running.
The HSZ3.75SL performs exactly like the manual HS3.75SL: up to 580 L/min and a maximum head of 10.8 m (50Hz). It uses a urethane-rubber semi-vortex impeller with a shaft-mounted sintered-alloy agitator and dual silicon carbide mechanical seals, and weighs 19.6 kg.
Selection note: the HSZ3.75SL trades head for volume. If the discharge point is high or the hose run is long, choose the HSZ3.75S 110V, which reaches 18 m. If your site has a standard single-phase supply rather than 110V, choose the HSZ3.75SL standard-voltage version. If you do not need automatic start/stop, the manual HS3.75SL is the alternative. These are dewatering pumps, not sewage or slurry pumps, and are not suitable for raw sewage, fibrous solids or settled sludge.
Key features
- Automatic operation: one float switch controls start and stop, eliminating dry-running to cut power use and extend service life. The float switch comes fitted to the pump.
- High-volume design: 80 mm discharge and up to 580 L/min for low-head, high-volume drainage.
- Anti-air-lock agitator: a shaft-mounted sintered-alloy agitator prevents the air lock that tends to occur on semi-vortex pumps.
- Side discharge with spiral casing: solids pass through more smoothly, and the external side outlet helps draw them in. Solids up to 7 mm.
- Abrasion-resistant wear parts: Tsurumi rates their durability as equivalent to its three-phase drainage pumps.
- Dual inside mechanical seals: silicon carbide faces in an oil chamber, with Tsurumi's Oil Lifter keeping the faces lubricated and cooled down to about 1/3 of the normal oil level. A nitrile rubber (NBR) V-ring acts as a dust seal.
- Built-in circle thermal protector (CTP): cuts the motor circuit directly on overheating or overcurrent.
- Anti-wicking cable entry: stops water creeping into the motor by capillary action if the sheath is damaged or the cable end is submerged, and prevents condensation inside the motor housing. A cable clip protects against tugging.
- Resin stand: prevents scratching of the floor.
Applications
- Construction sites: excavation, basement and temporary site dewatering on 110V site power
- Sumps and pits: unattended automatic drainage with the float switch
- Basements, plant rooms and car parks: standing water removal
- Storms and flooding: emergency drainage
- Equipment hire: portable design that moves easily between sites
Performance
The 10.8 m maximum head is the head at near-zero flow, and the 580 L/min (0.58 m³/min, about 34.8 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. Figures are at 50Hz; Tsurumi UK lists the same performance for the 110V and standard-voltage versions.
Technical specifications
TSURUMI HSZ3.75SL 110V technical specifications (50Hz)
| Item | Specification |
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| General |
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| Model | HSZ3.75SL (110V version) |
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| Type | Portable dewatering pump (automatic), single-phase submersible |
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| Discharge bore | 80 mm (3 in) |
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| Discharge connection | Hose coupling (standard); male threaded coupling for pipe available on special request |
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| Operation | Automatic (float switch) |
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| Hydraulic performance |
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| Max. head (at zero flow) | 10.8 m |
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| Max. capacity (curve end point) | 580 L/min (0.58 m³/min / approx. 34.8 m³/h) |
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| Max. solids size | 7 mm |
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| Impeller | Semi-vortex, urethane rubber |
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| Electrical |
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| Motor output | 0.75 kW |
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| Motor | Dry-type induction motor, 2-pole, insulation class E, continuous-duty rated |
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| Power supply | Single-phase 110V 50Hz |
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| Starting method | Capacitor run |
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| Synchronous speed | 3000 min⁻¹ (50Hz) |
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| Motor protection | Built-in circle thermal protector (CTP) |
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| Cable | 5 m PVC cable |
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| Seals |
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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 (dust seal) | Nitrile butadiene rubber (NBR) |
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| Materials |
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| Impeller | Urethane rubber |
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| Agitator | Sintered alloy |
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| Pump casing | Ductile cast iron |
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| Shaft | 403 stainless steel |
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| Stand | Resin |
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| Dimensions and weight |
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| Dry weight | 19.6 kg |
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| Dimensions (A × D × H) | 288 × 184 × 425 mm |
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| Discharge centre height (B) | 249 mm |
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| Min. required space (F) | 350 mm |
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| Float switch levels (FL1 min. / FL2 max.) | 150 mm / 475 mm |
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Sources: Tsurumi single-phase portable pumps catalogue (IB101), Tsurumi Hong Kong and Tsurumi Global HSZ product pages; 110V version data from Tsurumi UK and Tsurumi Europe (50Hz). Tsurumi notes that published data may differ from the actual product, so obtain the delivery specification sheet before use. Voltage as per nameplate.
HSZ automatic series comparison
Tsurumi HSZ series and related models (50Hz)
| Model | Discharge | Power | Max. head | Max. capacity | Version |
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| HSZ2.4S 110V | 50 mm | 0.4 kW | 12 m | 200 L/min | Automatic, 110V |
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| HSZ2.75S 110V | 50 mm | 0.75 kW | 18 m | 230 L/min | Automatic, 110V |
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| HSZ3.75S 110V | 80 mm | 0.75 kW | 18 m | 300 L/min | Automatic, 110V |
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| HSZ3.75SL 110V (this product) | 80 mm | 0.75 kW | 10.8 m | 580 L/min | Automatic, 110V |
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| HSZ3.75SL | 80 mm | 0.75 kW | 10.8 m | 580 L/min | Automatic, standard voltage |
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| HS3.75SL | 80 mm | 0.75 kW | 10.8 m | 580 L/min | Manual (no float) |
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Optional accessories
- 80 mm (3-inch) discharge hose to fit the standard hose coupling.
- Male threaded coupling for pipe connection (special order).
- 110V 50Hz site isolating transformer, if the site has no 110V supply.
Safety and installation
- Connect only to a single-phase 110V 50Hz supply, normally through a site isolating transformer. Never connect it to 230V.
- Electrical connection must be made by a registered electrical worker in line with local regulations, with a proper earth. An outlet with earth-leakage (RCD) protection is recommended.
- Lift and lower the pump by its handle, never by the cable. Protect the cable from damage; a damaged cable must be replaced or repaired before use.
- Allow a pit at least 350 mm wide and make sure the float moves freely without catching on the cable or the pit wall.
- The built-in thermal protector is a safeguard, not a reason to let the pump run dry for long periods. Always isolate the power before inspection or servicing.
- Stand the pump on firm ground or a raised base so it does not sink into mud.
- Do not use in flammable or explosive atmospheres, and do not pump flammable or corrosive liquids, seawater or hot liquids. Tsurumi Europe publishes a liquid temperature range of 0–40 °C and pH 5–9.
Wear parts and routine checks
- The impeller, agitator and mechanical seals wear gradually in use. Have the pump inspected if flow drops noticeably.
- Check the oil in the oil chamber regularly and replace it with turbine oil ISO VG32 (160 ml) as needed. If the oil is cloudy or contains water, have the shaft seals inspected promptly. The Oil Lifter only maintains lubrication down to about 1/3 of the oil level, so do not leave the oil low.
- Check regularly that the float switch operates correctly and that the cable sheath is undamaged.
