Case-study note: This page documents a completed historical reference deployment for Guizhou Transportation Group. The project data is retained as an engineering reference for similar TethPower configurations; current product models and specifications should be reconfirmed for each new project.
Project Objective: Keep Power, Water Pressure and Personnel on the Ground
High-rise glass cleaning creates two independent endurance problems for a drone: electrical power and water delivery. A battery-only aircraft must land for battery changes, while an onboard water tank would quickly consume payload and require repeated refilling. The reference project solved both constraints from the ground.
The aircraft received continuous electrical power through a high-voltage tether while high-pressure water travelled through a separate hose to the airborne spray lance. Operators therefore managed the cleaning process from ground level while the drone handled positioning and spray work at height.
Dual-Tether Architecture
| Path | What it carries | Engineering role |
|---|---|---|
| Power tether | High-voltage DC from the ground power unit to the airborne converter | Supports long-duration aircraft and payload operation without relying on battery-only endurance. |
| Water tether | Pressurized water from the ground pump to the airborne lance | Maintains a continuous water supply and avoids lifting a large onboard water tank. |
Reference Performance Recorded for the Project
| Indicator | Reference Project Result |
|---|---|
| Cleaning productivity | 800-1,000 m²/h |
| Spray pressure | Up to 20 MPa in the project acceptance context |
| Continuous operation | 24+ hours capability reported for the integrated system |
| Personnel at height | No cleaning worker required to remain suspended at the facade |
| Acceptance | Full operational testing and formal acceptance were completed; source project records report all specified performance indicators passed |
These values describe this specific deployment and should not be treated as universal guarantees. Cleaning speed and pressure at the facade depend on pump selection, hose length, nozzle, water source, contamination, building geometry, weather and operator procedure.
Reference System Configuration
Ground Power Unit - G40Pro Reference Configuration
Ground tethered power unit used in the reference cleaning deployment.
| Parameter | Reference Value |
|---|---|
| Input | 380 V AC, 3-phase, 4-wire |
| Output voltage | 0-1000 V DC, adjustable |
| Rated output power | ≤26 kW |
| Tether length | 120 m standard / up to 300 m in the source configuration |
| Cable diameter | ≤6.4 mm |
| Cable weight | ≤4.4 kg per 100 m |
| Operating temperature | -20°C to +60°C |
| Reel mode | Passive pay-out + active rewind |
| Maximum rewind speed | Up to 2 m/s |
The reference enclosure used FR4 non-conductive fiberglass composite. The source specification lists dielectric strength of 15 kV/mm, together with a motorized reel, anti-static brush and guide pulley for field cable management.
Airborne Power Module - DF-FC100 Reference Configuration
Reference airborne DC/DC power module with front cooling and connector detail.
| Parameter | Reference Value |
|---|---|
| Input voltage | 800-1000 V DC |
| Output voltage | 58.8 V DC |
| Rated output current | 400 A |
| Rated output power | ≥24 kW |
| Peak output power | ≥32 kW |
| Conversion efficiency | ≥97% |
| Protection rating | IP65; partial components IP67 in the source configuration |
| Operating temperature | -26°C to +40°C |
| Storage temperature | -40°C to +65°C |
| Altitude rating | 0-3,000 m |
| Weight | ≤9.0 kg |
The source module includes over-voltage, under-voltage, over-current, over-temperature and abnormal-power protection with active forced-air cooling and real-time status monitoring.
Telescopic High-Pressure Spray Lance - AF-Q2
Telescopic airborne spray lance used for close-range facade washing.
| Parameter | Reference Value |
|---|---|
| Retracted length | 100 cm |
| Extended length | 375 cm |
| Internal hose pressure rating | 25 MPa |
| Weight | 1 ± 0.2 kg |
| Inlet quick-connect ID | 15 mm |
| Outlet quick-connect ID | 12 mm |
| Nozzle change | Tool-free quick release |
| Length adjustment | Rotary locking collar |
Ground High-Pressure Water Pump - B7X
Reference ground pump with buffer tank for continuous water delivery.
| Parameter | Reference Value |
|---|---|
| Input | 380 V AC, 3-phase, 4-wire |
| Pump motor | 5.5 kW |
| Maximum nozzle pressure | 15 MPa |
| Flow rate | 17 L/min |
| Water buffer | 80 L |
| Dimensions | 72 × 62 × 100 cm |
| Weight | 90 kg |
DJI FC100 Platform Integration
DJI FC100 platform configured for the reference dual-tether cleaning project.
| Parameter | Source Reference |
|---|---|
| Maximum takeoff weight | 149.9 kg |
| Maximum lift payload | 55.2 kg |
| Ingress protection | IP55 |
| Hover wind resistance | 12 m/s |
| Positioning | RTK + multi-radar, described in source material as millimetre-grade |
| Obstacle sensing | Multi-radar + quad-camera vision system |
What the Integration Teaches
Reference on-site facade cleaning operation.
Power and water must be sized together. A longer hose adds weight and pressure loss; a longer electrical tether adds cable weight and voltage drop. Neither can be selected independently.
Payload margin is a system budget. The airborne power module, lance, water line, fittings and mounting hardware all consume the FC100 payload margin before cleaning starts.
Pressure at the pump is not pressure at the nozzle. Working height, hose diameter, flow and fittings determine the actual pressure available at the facade.
Long-duration power changes the workflow. When battery swaps are no longer the dominant interruption, water supply, cleaning chemistry, facade path planning and operator fatigue become the next operational limits.
Reference data must be recalculated for each building. Height, stand-off distance, wind corridor, facade material and water source can materially change the configuration.
Suitable Project Types
High-rise glass curtain wall cleaning
Transportation hubs, station facades and large public buildings
Atria and difficult-access exterior surfaces
Bridge or cable-stayed structural cleaning where an aerial spray tool is appropriate
Industrial facades and large vertical surfaces after site-specific safety review
Frequently Asked Questions
What does “dual tether” mean in a cleaning drone system?
It means the drone is supported by two ground-fed service paths: an electrical tether for continuous power and a water hose for cleaning fluid delivery.
Can the FC100 run continuously for 24 hours?
The reference project describes 24+ hour system capability, but an actual operating schedule must account for aircraft inspection, motor temperature, environmental limits, water supply and crew procedures. Treat continuous-power capability and uninterrupted flight as different questions.
Does a 15 MPa pump always provide 15 MPa at the airborne nozzle?
No. Pressure at height depends on hose length/diameter, flow, fittings and vertical head. The water circuit must be calculated for the project.
Can the same configuration be used for a 300 m building?
Not by assumption. Electrical cable weight/voltage drop, water-hose weight/pressure loss, aircraft payload and local flight constraints all need to be recalculated for the target height.
What should be provided for a new project?
Building height, cleaning height, aircraft model, target pressure/flow at the nozzle, water source, available 3-phase power, facade material, expected wind and preferred working duration.
Talk to TethPower About Your Configuration
For a new FC100 cleaning project, send the target height, water pressure/flow, hose length, available AC supply and cleaning geometry. TethPower can size the power tether, airborne converter and water-delivery interface as one system.