1. General Information

This manual is an essential part of the Wilo-Sub TWI 4-6 pump product, providing instructions for installation and operation. It must be kept near the product and followed strictly to ensure safe and proper use. The manual reflects the current product version and safety standards at the time of printing.

2. Safety Instructions

Safety guidelines are critical and must be read by all installers and operators. Warnings are categorized by severity: DANGER (immediate risk of death or severe injury), WARNING (risk of serious injury), CAUTION (risk of equipment damage), and NOTE (operational advice). Only qualified personnel should perform installation and maintenance. Compliance with accident prevention and electrical safety regulations is mandatory.

3. Transport and Storage

• Inspect the pump upon receipt for damage and report promptly.
• Use designated lifting brackets for transport; never lift by the cable.
• Protect the pump from moisture, frost, heat, sunlight, and mechanical damage.
• Seal pressure outlets to prevent contamination.
• Store horizontally on a firm, level surface.
• Protect power cables from damage and moisture; note motor filling freezes below -8°C.

4. Intended Use

The pumps are designed for clean or slightly contaminated water without long fibers or abrasive particles. Typical uses include boreholes, cisterns, domestic water supply, irrigation, and industrial pressure boosting. Pumps must be fully submerged and installed vertically or horizontally with a cooling jacket pipe. Use outside these parameters is improper and voids warranty.

5. Product Specifications

5.1 Type Code

Example: WILO-Sub TWI 4.01-09-B EM, where components indicate pump type, borehole diameter, flow rate, stages, generation, and motor type.

5.2 Technical Data

• Max sand content: 50 g/m³
• Voltage: Single-phase 230 V (4"), three-phase 400/480 V (4" and 6")
• Protection class: IP68
• Max flow rate: up to 25 m³/h (4"), up to 97 m³/h (6")
• Max head: up to 340 m (4"), up to 520 m (6")
• Discharge sizes: 1¼" to 3" depending on pump size
• Medium temperature: +3 to 30 °C
• Max submersion depth: 350 m
• Max switching frequency: 20 starts per hour

5.3 Standard Delivery

• Submersible motor pump with integrated non-return valve
• Connection cable (length varies)
• 230 V control box with capacitor, thermal protection, on/off switch
• Installation and operating manual

5.4 Optional Accessories

• Non-return valve at borehole outlet
• Dry-run protection (float switch or electrode)
• WILO-ER control unit for motor protection and water level monitoring
• Motor cables (kits or by meter)
• Pressure and storage tanks
• Plug & Pump packages for fluid control and pressure switching

6. Description and Function

The pump is a fully submersible, multistage motor pump with radial or semi-axial impellers, featuring a built-in non-return valve, optimized bearings, robust cable protection, and corrosion-resistant stainless steel parts. The motor is hermetically sealed with varnished windings and self-lubricating bearings. Cooling is via heat transfer to the pumped medium flowing along the motor housing, requiring minimum flow velocities of 10 cm/s (4") or 16 cm/s (6").

6.1 Soft Start and Frequency Converter Use

• Maintain minimum cooling flow velocity at all times.
• Current must not exceed rated motor current.
• Soft starter ramp times: 0-30 Hz max 1 sec; 30 Hz to rated frequency max 3 sec.
• Starting voltage minimum 55% of rated voltage.
• Bypass soft starter after normal operation to reduce losses.
• Frequency converter operation allowed only between 30 Hz and rated frequency.
• Allow at least 60 seconds cooling between stops and restarts.
• Voltage spikes max 1000 V; voltage rise max 500 V/µs.
• Additional filters required if control voltage exceeds 400 V.

7. Installation and Electrical Connection

7.1 Installation

• Install vertically or horizontally with cooling jacket pipe.
• Use water jacket for boreholes larger than pump size to ensure cooling.
• Recommended borehole sizes: 6" for 4" pumps >9 m³/h, 8" for 6" pumps >30 m³/h.
• Ensure sufficient water inflow matching pump capacity.
• Lower pump using hoist with chain/tripod or winch; never by cable.
• Maintain minimum 0.3 m clearance above borehole bottom.
• Check insulation resistance before and during lowering (minimum 2 MΩ).
• Use fixed or flexible piping sized 1¼" to 3"; secure flexible pipes with safety cables.
• Install non-return and shut-off valves at borehole outlet.
• For water pressures >180 m water column, use non-return valve rated ≥20 bar at pump outlet.

7.2 Electrical Connection

• Qualified electricians must perform electrical installation per local regulations.
• Supply voltage and current must match pump specifications.
• Use compliant cables and follow control box wiring diagrams.
• Verify maximum cable length based on motor current and cable cross-section.
• Improper connection risks fatal electric shock.

Technical Specifications

Detailed electrical and mechanical data include cable cross-sections, motor power ratings, operating voltages, and current consumption for single-phase (EM) and three-phase (DM) motors. Cable diameters and maximum lengths vary by motor power and starting method (direct or star-delta). Motor weights per meter of cable are specified.

• Single-phase motors: 230 V, 50/60 Hz, 0.25 kW to 2.2 kW.
• Three-phase motors: 400 V (50 Hz) or 480 V (60 Hz), 0.37 kW to 45 kW.
• Capacitor sizes and current consumption detailed for single-phase motors.
• Cable sizing recommendations prevent voltage drops.

Installation and Operation Instructions

Electrical Connection: The cable between control box and pump must remain intact (contains capacitors for EM versions). Grounding is mandatory. Motor protection via thermal or magnetic switches is required.

Rotation Direction Check (Three-phase motors): Verify correct rotation by measuring discharge water pressure. Incorrect rotation reduces flow and requires swapping two power phases.

Commissioning: Verify electrical connections, motor protection, and fuse ratings before startup. Check phase current against nameplate and voltage tolerance ±10%. Vent pressure connection to avoid shocks. Close valves during startup to minimize pressure surges and sand ingress. Limit starts to 20 per hour. Operate within catalog performance curve range. Avoid running with closed valves for long periods.

Operating Conditions

• Medium temperature range: 3°C to 30°C at nominal current.
• Minimum cooling water flow velocity: 10 cm/s (4" motors), 16 cm/s (6" motors).
• Reduce pump capacity proportionally for higher temperatures; do not exceed 55°C.
• Motor filling level checks and corrections must be done by qualified personnel; refilling allowed only by manufacturer for TWI4 motors.

Maintenance and Troubleshooting

Maintenance and repairs require qualified personnel. Disconnect power and secure against accidental re-energization before work. Cable repairs must be done by certified electricians. No special maintenance needed during normal operation.

• Common issues and solutions:
• Pump does not start: Check supply voltage, cable integrity, motor protection settings.
• Frequent starts: Reduce start cycles to prevent overheating.
• Pump runs but no water: Check water level, vent pump, clean intake filters, verify motor rotation.
• Frequent cycling: Adjust pressure switch differential, check electrode installation, adjust expansion tank pre-charge or size.

Regulatory Compliance and Certifications

The product complies with European directives: Machinery Directive 98/37/EC, Electromagnetic Compatibility Directive 2004/108/EC, Low Voltage Directive 2006/95/EC. Harmonized standards include EN 809, EN 50081-1, EN 50082-1, EN 60034-1. Declaration of conformity is valid only if no unauthorized modifications are made.

Contact and Support

Wilo AG offers international support with subsidiaries and offices worldwide. Spare parts orders must include complete nameplate data to avoid errors.

International Offices

• Asia: China, Korea, Taiwan, Vietnam, Kazakhstan, Lebanon, Saudi Arabia, UAE.
• Europe: Extensive presence including many countries such as Germany, France, UK, Italy, Russia, and others.
• Americas: USA, Argentina.
• Africa: South Africa.

German Regional Sales Offices

• Hamburg (North)
• Berlin (East)
• Dresden (Saxony/Thuringia)
• Munich (Southeast)
• Stuttgart (Southwest)
• Frankfurt (Rhine-Main)
• Düsseldorf (West)

Specialized Teams and Services

• Competence teams for Building Technology, Municipality, Construction, and Mining sectors.
• Customer service includes repairs, spare parts, commissioning, inspection, technical advice, and quality analysis.
• Customer service availability: Monday to Friday 7:00–17:00; weekends and holidays 9:00–14:00 with electronic standby and callback guarantee.

Additional Information

• Further subsidiary addresses available on www.wilo.de and www.wilo.com.
• Telephone charges for German calls vary; mobile network charges may differ.
• Document status as of August 2007.

Critical Points

• Global network ensures local support and service availability.
• Clear segmentation of sales offices and competence teams enables targeted assistance.
• Multiple contact channels enhance accessibility.