Field reference for utility scale solar technicians. 7 entries, taken from the FieldWatt app.
Reference notes from FieldWatt, the offline field toolkit for utility scale solar commissioning and O&M technicians. It works with no cell signal, because the sites do not have any.
Get FieldWatt on the App StoreNEXTracker horizontal single axis rows are independent and self powered: each row carries its own PV powered supply with battery backup, a controller, and roughly a 24 volt DC motor driving one slewing drive at the row center. Rows communicate wirelessly with a network control unit. One dead row is a row level problem (motor, controller, battery, drive); many dead rows point to the network control unit, weather feed, or a site wide stow command.
Verify component names and voltages against the current NEXTracker manual for the installed generation.
To stow rows for cleaning: switch the system from AUTO to MANUAL, wait 2 to 3 minutes for the command to propagate and the rows to settle, then enable CLEANING mode so the rows move to the cleaning position. When finished, disable CLEANING and return the system to AUTO, and confirm the rows resume tracking. Rows left in MANUAL do not respond to weather stow commands.
Never leave the site with rows in MANUAL. Confirm return to AUTO and verify rows are tracking before departure; a row stuck flat in a hail or high wind event is exposed.
Verify mode names and sequence against the current NEXTracker manual for the installed control system.
Weather stow is the tracker protection function that matters most. On a preventive maintenance visit, command each stow type from the control system and verify rows physically reach the stow angle: wind stow, snow stow, and flood stow where equipped. Confirm the anemometer and any snow or flood sensors are reporting live plausible values, and keep sensor lenses and screens clean. A stow test that fails is an urgent finding, not a punch list item.
Coordinate stow tests with the control room so operators know rows are moving on command. Keep personnel clear of moving rows.
Verify stow angles and trigger thresholds against the site settings file.
Keep row controller sensor lenses and inclinometers clean, and keep vegetation cut to within 6 inches of the ground under and around rows. Tall vegetation shades modules, blocks row travel, invites rodents that chew cabling, and turns into fuel. Verify row power supplies are charging their backup batteries; a row with a dead battery loses stow capability after sundown.
Follow the site vegetation management plan where one exists.
Array Technologies trackers use a centralized drive: one motor turns a rotating driveline that moves many rows together through gearboxes at each row. One motor failure therefore parks a whole block of rows, unlike independent row systems. Misalignment between linked rows indicates a slipped coupling, a failed gearbox, or a sheared driveline component, and it can twist the structure if driven further.
If linked rows disagree in angle, stop the drive before commanding more motion and inspect the driveline end to end.
Verify drive layout and component names against the current Array Technologies manual for the installed generation.
The recurring tracker O&M workload across brands: bearing wear and missed lubrication intervals; motor and actuator replacement; row controller and communication failures; sensor faults (inclinometer, anemometer, snow and flood sensors); row misalignment against commanded angle; and structural hardware loosening. A row consistently lagging its commanded angle by a few degrees usually has a mechanical problem (bearing, drive, mounting), while a row at a wild angle usually has a controller or sensor problem.
Follow manufacturer lubrication intervals and torque values.
A solid tracker PM visit covers: bearings and lubrication per interval; motor and actuator condition, current draw, and mounting; controller status, firmware, and communications; stow function tests for wind, snow, and flood; row alignment survey against commanded angle; sensor cleaning and verification; structural fastener spot checks; and vegetation clearance. Record every row that fails any check with block and row numbers so findings turn into work orders.
The Site Forms module includes a tracker PM checklist that mirrors this walkdown.
Reference notes from FieldWatt, the offline field toolkit for utility scale solar commissioning and O&M technicians. It works with no cell signal, because the sites do not have any.
Get FieldWatt on the App StoreThese notes are a field aid, not a substitute for the governing codes, the stamped drawings, the authority having jurisdiction, or manufacturer manuals. Verify against the current documentation for your installed equipment.