Trade encyclopedia

Outdoor lighting installer homeowner encyclopedia: low-voltage transformers, fixtures, timers, photocells, splices, voltage drop, and wet locations

Use this outdoor lighting guide to read GFCI trips, dim fixtures, water-filled lights, flicker, timer errors, exposed cable, and hot transformers, plan lens cleaning, cable protection, timer settings, transformer load, plant growth, and wet-location checks, price fixture quality, transformer capacity, cable runs, controls, trenching, masonry mounts, and line-voltage needs, and write contracts around fixture schedule, wattage, transformer taps, splice method, burial depth, controls, and aiming.

10 troubleshooting scenariosMaintenance scheduleCost and contract checks

Troubleshooting reference

Start with symptoms, rule out homeowner-safe basics, and escalate conservatively when safety, structure, utility service, or water damage is involved.

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Call soon

Breaker or GFCI trips when lights run

Pro-first

Likely causes

  • Water intrusion
  • Damaged cable
  • Overloaded transformer/circuit

Homeowner-safe check

Turn system off and do not keep resetting, especially in wet soil.

When to call

Call lighting pro/electrician promptly; line-voltage faults are urgent.

Routine

Several low-voltage fixtures are dim

DIY-safe basics

Likely causes

  • Voltage drop
  • Undersized transformer
  • Loose/corroded connection

Homeowner-safe check

Check timer/photocell settings and obvious disconnected leads without digging blindly.

When to call

Call routinely for voltage testing and cable sizing.

Routine

Fixture fills with water or corrodes

DIY-safe basics

Likely causes

  • Failed gasket
  • Poor drainage
  • Inground fixture not rated for location

Homeowner-safe check

Turn off affected fixture and avoid opening energized wet housings.

When to call

Call for sealed fixture replacement and drainage correction.

Call soon

Landscape lights flicker

DIY-safe basics

Likely causes

  • Loose splice
  • Failing LED driver
  • Transformer overload

Homeowner-safe check

Note whether flicker affects one fixture, one run, or the whole system.

When to call

Call if flicker follows rain or affects line-voltage fixtures.

Routine

Photocell/timer turns lights on at wrong time

DIY-safe basics

Likely causes

  • Wrong programming
  • Photocell shaded/dirty
  • Power outage reset

Homeowner-safe check

Clean photocell and reset schedule; verify daylight-saving settings.

When to call

Call routinely if smart controls or transformer programming fails repeatedly.

Routine

Path lights are knocked over or expose cable

DIY-safe basics

Likely causes

  • Shallow stakes
  • Landscape maintenance damage
  • Freeze heave

Homeowner-safe check

Turn off run before repositioning exposed cable.

When to call

Call if insulation is nicked, cable is buried near utilities, or fixtures repeat-fail.

Emergency

Line-voltage exterior fixture has water inside

Pro-first

Likely causes

  • Failed weatherproof box
  • Bad gasket
  • Improper fixture rating

Homeowner-safe check

Turn off the circuit and do not touch wet metal fixtures.

When to call

Call a licensed electrician immediately.

Call soon

Transformer hums, overheats, or smells

Pro-first

Likely causes

  • Overload
  • Shorted secondary
  • Failing transformer

Homeowner-safe check

Turn it off and keep combustible material away.

When to call

Call soon for load calculation and replacement.

Routine

New patio/deck work will bury lighting cable

DIY-safe basics

Likely causes

  • Cable path conflict
  • No conduit/sleeve
  • Future service access lost

Homeowner-safe check

Mark existing cable paths before excavation and sleeve planned crossings.

When to call

Call lighting installer before hardscape is installed.

Routine

Quote ignores voltage, transformer load, or fixture ratings

DIY-safe basics

Likely causes

  • Design shortcut
  • Premature LED failure
  • Safety/compliance gap

Homeowner-safe check

Require fixture model, beam spread, transformer capacity, cable gauge, burial method, and controls.

When to call

Call another installer if design is just a fixture count and lump sum.

Maintenance schedule

Seasonal tasks

Spring

  • In spring, uncover fixtures buried by mulch and confirm uplights are not aimed into new leaf growth.

Summer

  • During summer irrigation, look for fixtures holding water, corroded stakes, and GFCI trips after sprinkler cycles.

Fall

  • Before fall, reset timers for shorter days and clear leaves from well lights before heat damages lenses.

Winter

  • In winter, mark cable routes before snow removal and keep transformer vents clear of packed snow.

Interval tasks

Monthly

  • Monthly, walk the system at night for dim runs, flicker, glare, tipped path lights, and dark safety zones.

Annual

  • Yearly, clean lenses, check timer or photocell programming, tighten accessible mounting screws, and update the fixture map.

Every few years

  • Every few years, reassess transformer load, LED driver age, plant maturity, patio changes, and whether cable needs conduit sleeves.

Cost components

Labor

Labor risk is not just hours: fixture placement, cable routing, transformer sizing, controls setup, trenching, aiming, and night adjustments change how night aiming/design, cable trenching, transformer sizing, fixture mounting, splicing, control programming, and electrical coordination for line-voltage feeds plays out on site.

Materials

The quote should itemize fixtures, lamps, LED drivers, transformers, cable, connectors, stakes, conduit, timers, and photocells instead of hiding them inside fixtures, lamps/modules, transformers, low-voltage cable, connectors, stakes, conduit/sleeves, photocells, timers, smart controls, and GFCI/weatherproof parts.

Permits and inspections

Line-voltage lighting, exterior receptacles, trenching, pool areas, and smart-control wiring are the permit-sensitive parts to price before mobilization.

Broad range discipline

Use adding path lights, redesigning voltage runs, line-voltage work, and full landscape integration as the budget divider. Small path-light add-ons are modest; full-property designs, premium brass fixtures, smart controls, trenching, and line-voltage feeds increase cost.

What moves price

Pushes price up

  • Premium brass/copper fixtures; added cost is usually tied to fixture placement
  • Long cable runs/voltage drop; added cost is usually tied to cable routing
  • Smart zoning/controls; added cost is usually tied to transformer sizing
  • New line-voltage circuit; added cost is usually tied to controls setup

Can reduce price

  • Existing transformer capacity; lower pricing is likelier when fixtures is clearly defined
  • Short accessible runs; lower pricing is likelier when lamps is clearly defined
  • Standard fixtures; lower pricing is likelier when LED drivers is clearly defined
  • Install before hardscape/mulch; lower pricing is likelier when transformers is clearly defined

Hiring red flags

  • The contractor treats transformer sized without fixture wattage and cable length like a preference instead of a job control.
  • Nobody can explain the field check for wet-location ratings and splice method.
  • The cheaper scope strips out GFCI protection for line-voltage exterior fixtures before inspection is documented.
  • Warranty wording avoids LED driver, lamp life, water intrusion, and landscape damage exclusions and the return-visit trigger.
  • No voltage-drop or transformer-load calculation.
  • Buries cable too shallow or without protection where needed.
  • Uses indoor connectors outdoors.
  • Line-voltage work without licensed electrician.

Contract checklist

  • Fixture schedule, beam spread, color temperature, finish, mounting method, and aiming plan with brands, sizes, locations, and exclusions.
  • Transformer size, voltage taps, load calculation, cable gauge, run lengths, and burial depth before work starts, including who schedules inspections.
  • Splice connectors, conduit sleeves, line-voltage work, GFCI protection, photocell, timer, and smart controls for access, protection, cleanup, and disposal.
  • Landscape restoration, plant conflicts, mowing damage protection, patio or deck penetrations, and as-built map as unit pricing or written allowances.
  • Warranty for fixtures, lamps, drivers, transformer, water intrusion, controls, and maintenance expectations; closeout should bundle photos, manuals, warranty registrations, and releases.
  • Fixture model/material/beam spread, layout, zones, transformer size, cable gauge, and controls.
  • Burial depth, splice method, sleeves under hardscape, and utility locate.
  • Line-voltage/GFCI/weatherproof responsibilities if new power is needed.
  • Night aiming visit, timer/photocell setup, and plant-growth adjustment plan.
  • Warranty for fixtures, transformer, lamps/modules, and labor.

Warranty norms

Outdoor-lighting warranties differ for fixtures, lamps, LED drivers, transformers, and controls. Water intrusion from wrong ratings, mower damage, buried cable cuts, plant overgrowth, lightning, and owner re-aiming or smart-control changes are common limits.

Emergency