Power Tether

Sherpa Power Tether User Manual

Power Tether Quick Start Guide Video

Power Tether Quick Start Guide

Before You Start

You need:

Generator — 10,000+ running watts (Predator 13,000W Tri-Fuel used in testing)
50A generator extension cord — outdoor rated, 25 ft max
Lucid PDB Kit + updated top plate installed on the drone (required)

Recommended: manual hose reel (300 ft rated) for tether management, 1/4" OD hose.

Pre-Flight Safety Checks

Ground unit OFF
Generator OFF
Tether cable fully unspooled, never operate coiled
Walk the full 200 ft; inspect for cuts, kinks, abrasion, jacket damage
Cables not twisted or kinked
AS150U connectors clean and dry
Air unit connectors dry and secure
Ground unit positioned away from spray-back and runoff

Startup Sequence

1. Ground unit stays OFF until Step 6.

2. Connect tether to ground station (thin gray power cable).

3. Connect main power cable to generator — generator off, main breaker OFF. NEMA 14-50P plug: align the round/U-shaped pin, push straight in firmly (fits tight), confirm no gap.

4. Connect twist-lock cable to ground station. SS2-50R connector: align the "L" shaped grounding tab, seat fully, then rotate clockwise ~1/4 turn until it clicks. Do not screw the plastic threaded ring. To disconnect later, twist counter-clockwise first before trying to pull the plug out.

5. Connect drone power inputs: plug both AS150U connectors from the air unit into the drone.

6. Connect tether to air unit, listen for the click to ensure the connector is properly seated.

7. Plug battery into air module: drone powers on. Wait 2 minutes before starting the generator.

8. System check (generator still off):

Drone connects to controller
GPS good; verify compass against a known heading
No warnings or fault messages

Any issue → stop, do not proceed.

9. Power on ground unit:

Start the generator, warm up 1–2 minutes, then switch on the ground unit.

10. Pre-takeoff verification

controller must show:

Tether power detected
System ready for takeoff

11. Takeoff

Arm the drone and take off, make sure to look for any error messages.

Power Tether Ceiling

The cable is 200 ft. That is not your flight altitude. Air unit max continuous current is ~140A; firmware reduces the altitude limit as current climbs.

Max tested stable altitude: ~130–140 ft AGL (spray active, wind under 10 mph, 1/4" hose).

FAA Part 107 (<55 lb all-up weight) practical limits:

Configuration	Hose	Max Height
Window payload filled	3/8" softwash	~49 ft
Window payload filled	3/8" pressure	~42 ft
Window payload filled	1/4" high pressure	~66 ft
Window payload empty	3/8" softwash	~68 ft
Window payload empty	1/4" pressure	~91 ft
Software limit (no FAA cap)	1/4" high pressure	~140 ft

Staying FAA-compliant is the operator's responsibility.

Hose size is your biggest lever: switching 3/8" → 1/4" OD adds 25–30 ft of usable altitude.

Operating Limits

Wind: gusts above 15 mph at altitude can exceed the 140A ceiling and trigger auto-descent. When winds are above 15 mph reduce altitude, fly on batteries, or postpone.
Weather: no rain, snow, or fog. Ground unit must stay dry. Suspend for lightning.
Cold: let both units warm up before flight.
Battery backup is for emergency descent only, not for continuing a job.

Critical Do-Nots

Never fly with the cable partially coiled. Heat buildup damages the cable and can cause mid-flight failure
Never disconnect connectors under load
Never drive over, step on, or pinch the cable
Never force a connector; resistance means misalignment or debris
Never use a household extension cord or one over 25 ft
Never open or attempt to repair the air unit yourself.

Warning Messages & What to Do

Message	Action
Tether detected, waiting for generator power	Generator breaker is likely off, ensure it is flipped on.
Approaching weight limit / descend recommended	Warning, not a failsafe. Descend slightly, stop climbing.
Tether weight limit / auto-descend initiated	Current ceiling hit. Let it descend, don't fight it, assess before relaunch
Tether base station not detected	Power cycle generator and drone in correct sequence. Don't take off if it persists
Switch to battery / critical battery	Tether power lost. Land immediately — battery is for failsafe only

Total tether power loss: drone holds position 5 seconds, then lands automatically. The landing cannot be cancelled. System must be rebooted before flying again.

Smoke, burning smell, or heat warning:shut down ground unit power immediately, land, do not reconnect until the cause is found.

Snagged or entangled cable: do not try to fly free. Power down and clear it manually.

Every-Flight Maintenance

Inspect all connectors for dirt, moisture, bent pins, discoloration, arcing, or burn marks
Clean with dry compressed air only — no water, lubricants, or solvents
Seat all connectors until they lock
Replace any connector with burn marks, pitting, or damage before the next flight
Brief your ground crew on emergency callouts before each flight

Lucid Bots Inc. — Power Tether System