Division 05 — Runway Centreline Light Troubleshooting

01 · Runway Centreline Light Faults

15 of 15 topics published

RCL-191 Runway Centreline Light Not Working

Symptom — A runway centreline light (or a defined group of them) is not illuminating when the RCL series circuit is energised, reported either from a pilot report, ALCMS status, or routine night inspection.

Equipment / System

Runway Centreline Lights (RCL) — inset, bi-directional or variable-colour L-852 fixtures fed via individual isolation transformers off the RCL series circuit, in-pavement base cans (L-867), primary series cable loop back to the CCR.

Possible Causes

HighIsolation transformer failure at the fixture (open primary/secondary winding) — the single most common cause of one dark inset light

HighLamp/LED source failure inside the fixture

MediumSeries circuit primary cable fault or bad connection between fixtures (affects the light and everything downstream on that loop)

MediumBase can or L-823 connector failure — moisture ingress, corroded pin, or plug not fully seated

LowCCR itself at reduced/zero output (rules out a single-fixture problem — check whether other RCLs on the same circuit are also affected)

LowFixture physically damaged or displaced by jet blast, FOD, snow plough, or vehicle strike

Required Tools

Clamp-on series circuit ammeterTrue-RMS multimeter (CAT III)1000V insulation resistance tester (megger)Series circuit fault locator / TDRRCL as-built circuit and base-can layout drawingBase-can lifting tool and PPE for airside work

Safety Precautions

Coordinate all airside access through ATC/airfield operations and obtain a runway closure or inspection slot before approaching the light.
Treat the series circuit as energised until confirmed isolated at the CCR and locked out — RCL circuits run at up to several kV depending on loop length.
Use FOD-safe tools and account for every item before leaving the runway strip.

Diagnostic Procedure

ObservationCheck the ALCMS/CCR panel to see whether this is reported as a single light or part of a wider dark section, and confirm the actual current output of the affected RCL series circuit.
ObservationConfirm with a runway inspection whether only the one reported fixture is affected or a run of lights beyond it is also out — a single dark light plus everything downstream still lit points to that fixture; a dark run points to the loop upstream of it.
MeasurementWith the circuit isolated and LOTO applied, disconnect the fixture's L-823 plug and megger the isolation transformer primary and secondary windings.
MeasurementInspect the base can for water, debris, or a displaced/damaged connector, and check the fixture lamp/LED module for visible failure.
DecisionTransformer or lamp confirmed faulty at this fixture only → isolated single-fixture fault, proceed under RCL-192. Fault traces onto the primary loop or affects multiple fixtures → route to RCL-193.
Fault LocationIsolate the fault to the fixture (transformer, lamp, connector) or to the series cable loop feeding it.
Root CauseConfirm the specific failed component before replacement, rather than swapping parts speculatively.

Test Points

RCL fixture isolation transformer (primary/secondary)

L-823 secondary connector and base can

Series cable loop, both directions from the fixture

CCR output current at the panel

Root Cause Verification

After repair, re-energise the circuit, confirm the fixture lights at all intensity steps, and walk/drive the affected section at night or with the circuit on to confirm no adjacent lights were disturbed during access.

Corrective Action

Replace the failed isolation transformer or lamp/LED module.
Reseat or replace a corroded/damaged L-823 connector.
Repair the identified series cable fault.
Restore CCR output if the root cause was upstream rather than the fixture.

Preventive Action

Include RCL fixture and connector inspection in the routine night flight-check and periodic maintenance cycle.
Megger the series circuit periodically to catch developing insulation faults before they cause an outage.
Maintain an accurate base-can and circuit layout drawing to speed fault location.

Related References

SOP: SOP-RCL-01 (RCL Fault Isolation Procedure), SOP-CCR-04 (CCR LOTO Procedure)

Standards: ICAO Annex 14 Vol I, FAA AC 150/5340-30, FAA AC 150/5345-46 (L-852)

Diagram: RCL Circuit Layout Drawing, Base-Can Schedule

Case Study: Division 01 — CCR Troubleshooting (verify series circuit output); Division 24 — Complete Runway Lighting Failure

Rev 0 — Initial issue

RCL-192 Single Centreline Light Failure

Symptom — Exactly one runway centreline light is dark or malfunctioning while every other RCL on the same series circuit operates normally at the correct intensity.

Equipment / System

Individual RCL inset fixture, its isolation transformer, L-823 connector, and base can.

Possible Causes

HighIsolation transformer primary or secondary winding open-circuit

HighLamp or LED source burnt out or internally failed

MediumL-823 connector corroded, not fully mated, or pin damaged

MediumMoisture inside the base can causing an intermittent or dead short across the secondary

LowFixture internal wiring chafed or broken from vibration or thermal cycling

LowFixture mechanically cracked or displaced, breaking an internal connection

Required Tools

True-RMS multimeter1000V insulation resistance testerL-823 connector test adaptorBase-can lifting toolReplacement isolation transformer and lamp/LED module

Safety Precautions

Isolate and LOTO the series circuit before opening the base can — do not rely on the fixture appearing dark as proof of isolation.
Pump out any standing water in the base can before working, and treat it as potentially live until tested.

Diagnostic Procedure

ObservationConfirm at the CCR/ALCMS that only this one fixture is reported dark and that circuit current is at the expected value for the commanded step.
MeasurementWith the circuit isolated, open the base can, disconnect the L-823 connector, and megger the isolation transformer primary to earth, secondary to earth, and primary to secondary.
ObservationInspect the connector pins and body for corrosion, pitting, or incomplete mating, and check the base can for water or debris.
DecisionTransformer reads open or shorted → replace transformer. Transformer good but lamp/LED does not illuminate on a bench test → replace lamp/LED module. Both good → connector or fixture internal wiring fault.
Fault LocationIsolate to the transformer, lamp/LED module, connector, or fixture body.
Root CauseConfirm the specific component by bench-testing the removed part rather than assuming from visual inspection alone.

Test Points

Isolation transformer primary winding

Isolation transformer secondary winding

L-823 connector continuity

Lamp/LED module (bench test)

Root Cause Verification

Re-energise the circuit and confirm the fixture lights correctly at low, medium, and high intensity steps; recheck after 24–48 hours to rule out an intermittent connector fault.

Corrective Action

Replace the failed isolation transformer.
Replace the failed lamp/LED module.
Clean, re-grease, and reseat the L-823 connector, or replace it if corroded.
Dry out and reseal the base can if water ingress is found.

Preventive Action

Include base-can moisture checks in the periodic maintenance schedule.
Apply dielectric grease to connectors during every reconnection.
Track individual fixture failure history to identify chronically weak base cans (e.g., poor drainage) for remediation.

Related References

SOP: SOP-RCL-01 (RCL Fault Isolation Procedure), SOP-RCL-03 (Fixture Replacement Procedure)

Standards: FAA AC 150/5345-46 (L-852), FAA AC 150/5345-26 (isolation transformers), ICAO Annex 14 Vol I

Diagram: RCL Base-Can Detail Drawing

Case Study: Division 25 — Field Case Study Troubleshooting

Rev 0 — Initial issue

RCL-193 Multiple Centreline Light Failure

Symptom — A run of two or more adjacent runway centreline lights is dark or malfunctioning together, while the circuit remains energised and other sections of the same runway are lit normally.

Equipment / System

RCL series circuit primary cable loop and the group of fixtures fed by the affected section.

Possible Causes

HighPrimary series cable fault (cut, chafed, or moisture-degraded insulation) between the last working fixture and the first dark one

HighA single failed isolation transformer developing a short circuit, collapsing available voltage to downstream fixtures on the same loop

MediumDamaged or crushed duct/cable section from recent excavation, paving, or heavy vehicle loading

MediumWater ingress into a cable joint or pull box along the affected section

LowRodent or FOD damage to buried cable

LowA section isolator or field-splice left open after previous maintenance

Required Tools

Series circuit fault locator / TDR (time-domain reflectometer)1000V/2500V insulation resistance testerClamp-on ammeterCable route and joint location drawingExcavation permit and utility locate request if digging is required

Safety Precautions

LOTO the CCR before any cable work; series circuits can present a shock hazard well beyond the immediate fault location.
Obtain excavation clearance and utility locates before opening any pavement or verge if the fault requires digging.
Coordinate with ATC for any extended runway occupancy needed to trace the fault.

Diagnostic Procedure

ObservationConfirm the exact extent of the dark section from a runway inspection and cross-reference it against the circuit layout drawing to identify the cable segment(s) involved.
MeasurementWith the circuit isolated, megger the primary series cable in segments from accessible pull boxes or transformer base cans, working from each end of the affected section toward the middle.
MeasurementUse a TDR or fault locator referenced to the cable's known length to estimate the fault distance if a direct segment test is inconclusive.
DecisionInsulation resistance fails on a specific segment → cable/joint fault in that segment. All segments megger clear but a specific transformer reads shorted → that transformer is loading down the loop and starving downstream fixtures.
Fault LocationPhysically locate and expose the faulted cable segment or confirm the single shorted transformer.
Root CauseConfirm cause of the cable fault (mechanical damage, water tracking, age-related insulation breakdown) once exposed.

Test Points

Primary cable insulation resistance, segment by segment

Suspect transformer primary-to-secondary and to-earth

Pull box/joint condition along the affected run

CCR output current before and during isolation of suspect segment

Root Cause Verification

After repair, megger the full affected loop end-to-end, re-energise, and confirm all fixtures in the previously dark section illuminate correctly across all intensity steps.

Corrective Action

Repair or replace the faulted cable segment and joint.
Replace the shorted isolation transformer found to be loading the loop.
Restore any open section isolator/splice left from prior work.
Reinstate the duct/cable protection if mechanical damage was the cause.

Preventive Action

Include periodic full-loop insulation resistance testing in the PM programme, trending results year over year to catch degrading cable before failure.
Maintain accurate as-built records of every joint, pull box, and repair splice.
Coordinate with civil works teams before any excavation near known cable routes.

Related References

SOP: SOP-RCL-02 (Series Circuit Fault Location Procedure), SOP-CCR-04 (CCR LOTO Procedure)

Standards: IEC 60364 (insulation testing), ICAO Annex 14 Vol I, FAA AC 150/5340-30

Diagram: RCL Series Circuit Route Drawing

Case Study: Division 24 — Complete Runway Lighting Failure; Division 25 — Field Case Study Troubleshooting

Rev 0 — Initial issue

RCL-194 Centreline Light Flickering

Symptom — One or more runway centreline lights flicker, pulse, or vary in brightness instead of holding a steady output at the commanded intensity step.

Equipment / System

RCL fixture, isolation transformer, connector, and the series circuit supplying it.

Possible Causes

HighLoose or intermittent connection at the L-823 connector, causing contact resistance to vary under vibration or thermal movement

HighA partially failed or overheating isolation transformer with an intermittent internal short

MediumLamp/LED driver instability or a failing LED module nearing end of life

MediumIntermittent cable fault (chafed insulation making and breaking contact) rather than a solid open or short

LowCCR output instability itself, rather than a fixture-level fault — check whether flicker correlates with CCR step changes or load

LowMoisture inside the base can causing an intermittent leakage path

Required Tools

True-RMS multimeter with min/max holdOscilloscope or power quality logger for waveform captureThermal imaging cameraL-823 connector test adaptor

Safety Precautions

Treat intermittent faults as live until proven otherwise — a fault that comes and goes can still be present during handling.
LOTO the circuit before opening any base can even if the light appears steady at the time of access.

Diagnostic Procedure

ObservationConfirm whether the flicker is on a single fixture or several, and whether it correlates with a particular intensity step, time of day, or weather condition.
MeasurementLog CCR output current over a period spanning the reported flicker to rule out a source-side instability.
MeasurementWith the circuit isolated, inspect and re-torque the L-823 connector, and megger the isolation transformer under light mechanical flexing to try to reproduce an intermittent fault.
ObservationUse thermal imaging on the connector and transformer during a live period (from a safe distance/procedure) to spot a hot connection consistent with intermittent high resistance.
DecisionFlicker follows CCR current logging → CCR/source-side issue, route to Division 01. Flicker isolated to the fixture and reproducible by flexing the connector → connector or transformer fault.
Fault LocationIsolate to the connector, transformer, lamp/LED module, or cable, based on where the flicker could be reproduced or measured.
Root CauseConfirm by replacing the suspect component and re-testing under conditions that previously produced the flicker.

Test Points

L-823 connector contact resistance

Isolation transformer under mechanical flex

CCR output current trend log

Lamp/LED module bench test

Root Cause Verification

Monitor the repaired fixture over several operating cycles, including varying intensity steps and at least one period of the weather condition originally associated with the flicker, before closing out.

Corrective Action

Clean, re-grease, and properly seat the L-823 connector.
Replace a transformer confirmed to have an intermittent internal fault.
Replace a failing lamp/LED module.
Repair the identified intermittent cable fault.

Preventive Action

Torque-check connectors as a standard step in periodic maintenance, not only during fault response.
Include thermal imaging of connectors and transformers in the periodic PM cycle.
Trend CCR output logs to distinguish source-side from fixture-side intermittent issues early.

Related References

SOP: SOP-RCL-01 (RCL Fault Isolation Procedure)

Standards: FAA AC 150/5345-46 (L-852), ICAO Annex 14 Vol I

Diagram: RCL Circuit Layout Drawing

Case Study: Division 01 — CCR Troubleshooting (intensity step control)

Rev 0 — Initial issue

RCL-195 Centreline Light Dim

Symptom — A runway centreline light illuminates but appears noticeably dimmer than adjacent fixtures at the same commanded intensity step.

Equipment / System

RCL fixture optical/lamp assembly, isolation transformer secondary output, and lens condition.

Possible Causes

HighLens or prism heavily contaminated with rubber deposits, dirt, or surface degradation, reducing light transmission

HighIsolation transformer secondary output below rated value due to partial internal fault or incorrect tap

MediumLamp/LED module degraded or nearing end of life without having fully failed

MediumIncorrect or mismatched transformer rating installed at a previous replacement, under-driving the lamp

LowSeries circuit current below the correct value for the commanded step, affecting the whole loop rather than one fixture — check other fixtures on the same circuit

LowLens misaligned so that peak beam intensity is directed away from the design sightline

Required Tools

Light output/luminance meterTrue-RMS multimeterClamp-on ammeterLens cleaning kitIsolation transformer test set

Safety Precautions

LOTO the circuit before removing or cleaning a lens or accessing the fixture interior.
Allow the fixture to cool before handling if it has been recently energised at a high intensity step.

Diagnostic Procedure

ObservationCompare the reported fixture's apparent brightness against neighbouring fixtures at the same commanded step, ideally with a luminance meter rather than visual judgement alone.
MeasurementConfirm the series circuit current at the CCR matches the correct value for the commanded intensity step, to rule out a circuit-wide cause.
ObservationInspect the lens and prism for contamination, rubber deposit build-up, scratching, or UV degradation, and clean if required.
MeasurementWith the circuit isolated, check the isolation transformer secondary output and confirm its rated wattage/tap matches the design (e.g., correctly matched to the lamp/LED module in use).
DecisionCircuit current correct and lens clean but output still low → transformer or lamp/LED degradation. Lens found heavily contaminated → cleaning likely resolves it; re-check after cleaning before replacing parts.
Fault LocationIsolate to lens contamination, transformer output, or lamp/LED degradation.
Root CauseConfirm with a before/after luminance reading once the identified cause is addressed.

Test Points

Fixture luminance output vs. neighbouring fixtures

Series circuit current at CCR

Isolation transformer secondary voltage/wattage

Lens transmission condition

Root Cause Verification

Re-measure luminance output after corrective action and compare against neighbouring fixtures and the manufacturer's rated output for the commanded step.

Corrective Action

Clean the lens and prism assembly.
Replace an isolation transformer with an incorrect or degraded rating.
Replace a degraded lamp/LED module.
Correct any lens misalignment found during inspection.

Preventive Action

Include lens cleaning in the routine runway lighting maintenance cycle, especially on sections exposed to heavy rubber deposit build-up.
Verify transformer rating matches the specified lamp/LED module at every replacement.
Track luminance readings over time to catch gradual degradation before it becomes a reported fault.

Related References

SOP: SOP-RCL-04 (Lens Cleaning and Inspection Procedure)

Standards: ICAO Annex 14 Vol I (light intensity requirements), FAA AC 150/5340-30

Diagram: RCL Photometric Specification Sheet

Case Study: Division 26 — Photometric & Intensity Compliance

Rev 0 — Initial issue

RCL-196 Centreline Light Incorrect Color

Symptom — A runway centreline light shows the wrong colour for its position along the runway — for example, a white light in a section that should show alternating red/white, or a red light outside the final 300 m section.

Equipment / System

RCL variable-colour fixture (dual-filter or two-lamp red/white assembly) and its position within the runway lighting colour-change scheme.

Possible Causes

HighFixture installed in the wrong position, or swapped with a fixture from a different colour zone during previous maintenance

HighColour filter/lens cap missing, cracked, or incorrectly fitted on a variable-colour fixture

MediumWrong lamp/LED module fitted (single-colour module installed where a red/white or colour-changing module is specified)

MediumInternal colour-change mechanism or dual-source wiring fault in the fixture, causing it to default to the wrong element

LowAs-built colour zone boundary itself incorrect or not matching the current runway declared distances (e.g., after a threshold or runway length change)

Required Tools

RCL colour-zone layout drawing (current, cross-checked against declared distances)Fixture position/GPS reference toolReplacement colour lens/filter and correct lamp/LED moduleTrue-RMS multimeter

Safety Precautions

LOTO the circuit before removing the lens or accessing the fixture internals.
Confirm the correct colour-zone boundary against current declared distances before assuming the fixture is at fault — a runway declared-distance change can move the required colour transition point.

Diagnostic Procedure

ObservationConfirm the fixture's exact chainage/position against the current RCL colour-zone layout drawing to establish what colour it should be showing.
ObservationPhysically inspect the fixture for the correct lens/filter fitted, and confirm whether it is a single-colour or dual/colour-change type appropriate to its position.
MeasurementWith the circuit isolated, check the fixture's internal wiring/lamp arrangement against the manufacturer's colour-change wiring diagram if applicable.
DecisionFixture in the wrong zone or wrong lens fitted → correct the lens/fixture. Correct lens fitted but still showing wrong colour → internal colour-change mechanism or wiring fault.
Fault LocationIsolate to lens/filter selection, lamp/module mismatch, or internal colour-change fault.
Root CauseCross-check the corrected fixture against the layout drawing once repaired to confirm it now matches its designed colour for that chainage.

Test Points

Fixture chainage vs. colour-zone layout drawing

Lens/filter type fitted

Lamp/LED module type fitted

Internal colour-change wiring (if applicable)

Root Cause Verification

After correction, visually confirm the correct colour is displayed at the correct chainage during a night inspection, alongside the fixtures immediately either side of the colour-change boundary.

Corrective Action

Fit the correct colour lens/filter for the fixture's position.
Replace with the correct lamp/LED module type for that zone.
Repair or replace a faulty colour-change mechanism.
Relocate the fixture if it was found installed in the wrong position.

Preventive Action

Maintain the RCL colour-zone layout drawing current with any declared-distance changes.
Clearly label fixture types/colours on spares and during any maintenance swap to prevent zone mix-ups.
Include a colour-scheme spot-check in the periodic night inspection.

Related References

SOP: SOP-RCL-05 (Colour-Zone Verification Procedure)

Standards: ICAO Annex 14 Vol I (Table 5-1, centreline light colour), FAA AC 150/5340-30

Diagram: RCL Colour-Zone Layout Drawing

Case Study: Division 26 — Photometric & Intensity Compliance

Rev 0 — Initial issue

RCL-197 Centreline Light Wrong Intensity

Symptom — One fixture, a group of fixtures, or an entire RCL circuit displays a brightness level that does not match the intensity step commanded by the CCR/ALCMS.

Equipment / System

RCL fixture output relative to the commanded CCR intensity step, and the isolation transformer matching that step.

Possible Causes

HighIsolation transformer of the wrong wattage/tap fitted at this fixture relative to the design (common after an ad-hoc spares swap)

HighCCR itself outputting the wrong current for the commanded step — check whether the discrepancy affects only this fixture or the whole circuit

MediumLamp/LED module rated for a different current than the series circuit design (mismatched replacement part)

MediumRegulator/ALCMS step command not reaching this circuit correctly if only part of a runway is affected

LowLens or filter degradation making the light appear dimmer than its actual electrical intensity, which is a photometric rather than electrical fault (cross-check against RCL-195)

Required Tools

Clamp-on ammeterTrue-RMS multimeterLight output/luminance meterTransformer rating reference table

Safety Precautions

LOTO the circuit before inspecting or replacing any transformer.
Confirm actual circuit current at the CCR before concluding the fault is fixture-side.

Diagnostic Procedure

ObservationConfirm the CCR is actually outputting the correct current for the commanded step, using the CCR panel/ALCMS reading cross-checked with a clamp meter if available.
DecisionIf the whole circuit is affected, route to Division 01 (CCR intensity/step control) rather than continuing at fixture level. If only one fixture or a small group is affected, continue below.
ObservationInspect the affected fixture(s) and confirm the isolation transformer wattage/tap and lamp/LED module rating against the design specification for that circuit.
MeasurementCompare luminance output of the affected fixture(s) against neighbouring, correctly-performing fixtures at the same commanded step.
Fault LocationIsolate to a mismatched transformer, mismatched lamp/LED module, or (if ruled out at fixture level) a source-side step-control issue.
Root CauseConfirm by replacing the mismatched component with the correct rating and re-measuring output.

Test Points

CCR output current vs. commanded step

Transformer wattage/tap rating

Lamp/LED module current rating

Comparative luminance vs. neighbouring fixtures

Root Cause Verification

After correction, verify the fixture's output matches neighbouring fixtures across all intensity steps, not just the step at which the fault was originally reported.

Corrective Action

Replace the transformer with the correctly rated unit for the circuit design.
Replace the lamp/LED module with the correct current rating.
Escalate to CCR-level troubleshooting if the fault is confirmed circuit-wide.

Preventive Action

Maintain a clear parts specification/rating table at the maintenance store to prevent incorrect spares being fitted.
Verify transformer and lamp ratings as a standard check whenever a fixture component is replaced.
Include a step-by-step intensity comparison in the periodic night inspection.

Related References

SOP: SOP-RCL-01 (RCL Fault Isolation Procedure), SOP-CCR-08 (Intensity Step Verification)

Standards: ICAO Annex 14 Vol I, FAA AC 150/5345-46

Diagram: RCL Circuit Design Specification

Case Study: Division 01 — CCR Troubleshooting (Intensity Step Control); Division 26 — Photometric & Intensity Compliance

Rev 0 — Initial issue

RCL-198 Centreline Light Optical Failure

Symptom — A runway centreline light receives correct electrical power and the lamp/LED source operates, but the fixture fails to produce the correct beam pattern — light appears scattered, absent in the expected direction, or grossly asymmetric.

Equipment / System

RCL fixture optical assembly — reflector, prism/lens system, and internal beam-forming components.

Possible Causes

HighReflector detached, corroded, or coated with condensation/contamination, scattering rather than focusing the beam

HighPrism or lens cracked, fogged, or partially melted from a previous overheating event

MediumLamp/LED module not correctly seated in its optical focal position after a replacement

MediumInternal fixture component (baffle, mounting bracket) displaced by impact, altering the optical path

LowWrong lamp/LED module type fitted, with a different beam geometry than the fixture's optics were designed for

Required Tools

Beam pattern/goniophotometer test set (if available) or field beam-check procedureTorch/inspection lightFixture manufacturer optical assembly diagramReplacement optical components (reflector, lens/prism, lamp seat)

Safety Precautions

LOTO the circuit before opening the fixture for optical inspection.
Allow the fixture to cool fully before handling the optical assembly, particularly if overheating is suspected as the cause.

Diagnostic Procedure

ObservationConfirm the light source itself is operating correctly (verify against RCL-192/195) before concluding this is an optical rather than electrical fault.
ObservationWith the circuit isolated, open the fixture and visually inspect the reflector, prism, and lens for damage, contamination, or displacement.
MeasurementConfirm the lamp/LED module is correctly seated at the designed focal position per the manufacturer's optical assembly diagram.
DecisionPhysical damage or contamination found on optics → clean or replace the affected component. Optics appear intact but lamp/LED seating is incorrect → reseat correctly and re-check beam pattern.
Fault LocationIsolate to the reflector, lens/prism, lamp seating, or an internal displaced component.
Root CauseConfirm by a field beam-pattern check (or goniophotometer test if available) after correction, comparing against a known-good fixture of the same type.

Test Points

Reflector condition and alignment

Lens/prism condition

Lamp/LED module seating position

Comparative beam check against a known-good fixture

Root Cause Verification

Verify beam pattern visually from the design sightline (or with a goniophotometer if available) after repair, and re-inspect after several operating cycles to confirm the fix is stable under thermal cycling.

Corrective Action

Clean or replace the reflector.
Replace a cracked or fogged lens/prism.
Reseat the lamp/LED module to the correct focal position.
Replace any displaced internal optical component.

Preventive Action

Include an internal optical inspection in the periodic deep-clean/major maintenance cycle, not just external lens cleaning.
Handle optical components with clean gloves during any fixture work to avoid contamination.
Use only manufacturer-approved lamp/LED modules matched to the fixture's optical design.

Related References

SOP: SOP-RCL-06 (Optical Assembly Inspection Procedure)

Standards: FAA AC 150/5345-46 (L-852 photometric requirements), ICAO Annex 14 Vol I Appendix 2

Diagram: RCL Fixture Optical Assembly Diagram

Case Study: Division 26 — Photometric & Intensity Compliance

Rev 0 — Initial issue

RCL-199 Centreline Light Water Ingress

Symptom — Water is found inside the fixture housing, base can, or connector during inspection or maintenance, with or without an associated electrical fault already having occurred.

Equipment / System

RCL fixture housing, gasket/seal system, base can drainage, and secondary connector.

Possible Causes

HighFixture top-plate gasket degraded, cracked, or incorrectly seated, allowing surface water to enter

HighBase can drainage blocked or the can itself not properly sealed to the surrounding duct/pavement, allowing groundwater or surface runoff to collect

MediumL-823 connector boot/seal damaged or not fully engaged

MediumFixture frangible coupling or mounting bolts loose, breaking the seal against the top plate

LowPavement settlement or cracking around the fixture allowing surface water to track directly into the base can

LowCondensation accumulation from thermal cycling rather than external ingress, in a poorly ventilated fixture design

Required Tools

Insulation resistance tester (1000V/2500V)Wet/dry vacuum for base-can pump-outReplacement gaskets, seals, and connector bootsTorque wrench for top-plate fixing bolts

Safety Precautions

LOTO the circuit before opening a fixture or base can with standing water — water ingress significantly increases shock risk.
Do not assume a wet fixture is de-energised; test with a rated meter before hand contact.
Dispose of pumped-out water per site environmental procedure if contamination is suspected.

Diagnostic Procedure

ObservationConfirm the extent of water ingress — fixture housing only, base can, or both — and note whether any electrical fault (dim, dark, flickering) is already present.
MeasurementWith the circuit isolated, megger the fixture and transformer to confirm whether insulation has already been compromised.
ObservationInspect the top-plate gasket, connector boot, and base-can seal/drainage for the specific ingress path.
DecisionInsulation resistance already low → treat as an active electrical fault, replace affected components before re-energising. Insulation resistance still acceptable → address the sealing issue and monitor.
Fault LocationIsolate the specific ingress path — gasket, connector boot, base-can seal, or drainage blockage.
Root CauseConfirm the fixture and base can are fully dry and re-test insulation resistance before closing out.

Test Points

Insulation resistance, fixture to earth

Insulation resistance, transformer to earth

Top-plate gasket condition

Base-can drainage function

Connector boot integrity

Root Cause Verification

Re-test insulation resistance after drying and resealing, and re-inspect the fixture after the next significant rainfall to confirm the ingress path has been fully resolved.

Corrective Action

Replace the degraded top-plate gasket.
Clear or restore base-can drainage.
Replace the damaged connector boot/seal.
Torque the top-plate fixing bolts to specification.
Pump out and dry the base can fully before closing up.

Preventive Action

Include gasket and seal condition in the periodic maintenance checklist, replacing proactively on a defined interval rather than only on failure.
Check and clear base-can drainage as part of routine maintenance, especially before the wet season.
Track fixtures with a history of water ingress for targeted remediation (e.g., pavement or drainage correction).

Related References

SOP: SOP-RCL-07 (Water Ingress Response Procedure)

Standards: FAA AC 150/5345-46 (L-852 environmental sealing requirements), ICAO Annex 14 Vol I

Diagram: RCL Base-Can and Gasket Detail Drawing

Case Study: Division 25 — Field Case Study Troubleshooting

Rev 0 — Initial issue

RCL-200 Centreline Light Lens Damage

Symptom — The fixture lens (top cover) is found cracked, chipped, scratched, or discoloured during inspection, potentially degrading light output or compromising the environmental seal.

Equipment / System

RCL fixture lens/top cover assembly and its gasket interface with the fixture body.

Possible Causes

HighImpact damage from jet blast debris, FOD, snow plough contact, or aircraft/vehicle tyre strike

HighThermal shock cracking from rapid temperature change (e.g., de-icing fluid or snow contact on a hot lens)

MediumUV degradation and surface crazing from prolonged sun exposure over the lens service life

MediumRubber deposit build-up combined with aggressive cleaning causing surface scratching over time

LowIncorrect lens material or thickness fitted at a previous replacement, more prone to cracking under load

Required Tools

Visual inspection kit / torchCalipers or gauge to confirm lens thickness against specificationReplacement lens and gasket, correct part numberTorque wrench for lens retaining fixings

Safety Precautions

LOTO the circuit before removing a damaged lens.
Handle a cracked lens carefully — sharp edges and the possibility of it being under load from the fixture being driven over.

Diagnostic Procedure

ObservationDocument the type and extent of lens damage (crack, chip, discolouration) and photograph for the maintenance record.
ObservationCheck whether the damage has compromised the gasket seal, by inspecting for water ingress evidence inside the fixture (cross-reference RCL-199).
MeasurementConfirm the replacement lens is the correct part number, material, and thickness for this fixture type before fitting.
DecisionDamage is cosmetic only with seal intact and no ingress evidence → schedule replacement at next convenient window. Seal compromised or ingress found → treat as priority repair.
Fault LocationConfirm the lens itself as the fault, distinct from any underlying optical or electrical issue already present.
Root CauseWhere damage is impact-related, note the likely cause (FOD, snow plough, vehicle) for reporting and, if a pattern, for airside operational follow-up.

Test Points

Lens crack/chip extent and location

Gasket seal condition post-damage

Fixture interior for ingress evidence

Replacement lens part number/spec match

Root Cause Verification

After lens replacement, confirm the gasket seal is fully seated, re-torque fixings to specification, and re-test insulation resistance to confirm no residual ingress.

Corrective Action

Replace the damaged lens with the correct specification part.
Replace the gasket at the same time as the lens.
Repair any underlying fixture damage found during the inspection.

Preventive Action

Include lens condition in the routine visual inspection cycle, flagging early crazing/scratching before it progresses to cracking.
Report recurring impact damage patterns to airfield operations for possible operational or FOD-control follow-up.
Use only the specified lens material/thickness for the fixture type.

Related References

SOP: SOP-RCL-08 (Lens Replacement Procedure)

Standards: FAA AC 150/5345-46 (L-852), ICAO Annex 14 Vol I

Diagram: RCL Fixture Lens Assembly Drawing

Case Study: Division 27 — FOD & Physical Damage Case Studies

Rev 0 — Initial issue

RCL-201 Centreline Light Prism Damage

Symptom — The internal prism element of the fixture (used to split or direct the beam for bi-directional or variable-colour operation) is found cracked, displaced, discoloured, or delaminated.

Equipment / System

RCL fixture internal prism assembly, distinct from the outer lens/top cover.

Possible Causes

HighThermal stress cracking from repeated heating/cooling cycles, particularly at high intensity steps

HighImpact transmitted through the lens to the prism during a FOD or vehicle strike event

MediumPrism mounting bracket loose or displaced, allowing movement and eventual cracking under vibration

MediumMoisture ingress causing delamination or clouding of a laminated/coated prism

LowIncorrect prism type fitted for this fixture's colour/direction configuration at a previous repair

Required Tools

Inspection torch and magnifierFixture manufacturer internal optical assembly diagramReplacement prism, correct part number and orientationTorque wrench for internal fixings

Safety Precautions

LOTO the circuit before opening the fixture to access the prism.
Allow the fixture to cool before handling, as prisms are typically mounted close to the lamp/LED heat source.

Diagnostic Procedure

ObservationWith the outer lens removed, inspect the prism for cracking, displacement, clouding, or delamination, comparing against the manufacturer's optical assembly diagram for correct orientation.
ObservationCheck the mounting bracket/retaining clips for looseness or damage that could indicate the root cause of movement-related cracking.
MeasurementConfirm the beam pattern is affected by checking the fixture against RCL-198 (optical failure) criteria if not already assessed.
DecisionPrism cracked/displaced with intact mounting → replace prism only. Mounting bracket also damaged → replace bracket and prism together.
Fault LocationIsolate to the prism itself or to its mounting/retention hardware.
Root CauseConfirm correct prism orientation and secure mounting after replacement, matching the fixture's designed colour/direction configuration.

Test Points

Prism physical condition and orientation

Mounting bracket/retaining clip integrity

Beam pattern post-replacement

Correct prism part number for fixture configuration

Root Cause Verification

After replacement, verify the beam pattern and colour presentation (if applicable) match the fixture's designed configuration, and re-inspect after several thermal cycles.

Corrective Action

Replace the damaged prism with the correct part number and orientation.
Replace or repair a damaged mounting bracket.
Verify and correct any resulting beam pattern or colour presentation issue.

Preventive Action

Include prism condition in periodic deep-clean/internal inspections rather than relying on external lens checks alone.
Ensure replacement prisms are sourced from the fixture manufacturer to guarantee correct optical properties.
Investigate recurring thermal cracking on a given fixture type for a possible design or ventilation issue.

Related References

SOP: SOP-RCL-06 (Optical Assembly Inspection Procedure)

Standards: FAA AC 150/5345-46 (L-852), ICAO Annex 14 Vol I Appendix 2

Diagram: RCL Fixture Optical Assembly Diagram

Case Study: Division 26 — Photometric & Intensity Compliance

Rev 0 — Initial issue

RCL-202 Centreline Light Alignment Error

Symptom — The fixture is correctly powered and optically intact, but its beam is not correctly aimed relative to the runway centreline and the intended sightline, resulting in reduced apparent intensity from the design viewing angle.

Equipment / System

RCL fixture mounting/levelling relative to pavement surface and the design beam elevation/azimuth.

Possible Causes

HighFixture rotated within its base can during installation or after a maintenance disturbance, changing beam azimuth

HighPavement settlement or resurfacing changing the fixture's height/level relative to the design reference surface

MediumFixture top plate not correctly torqued, allowing rotation under aircraft/vehicle loading over time

MediumBase can itself installed off the correct centreline offset or at an incorrect depth

LowFrangible coupling partially sheared, tilting the fixture without fully failing

Required Tools

Inclinometer/levelFixture alignment jig (if specified by manufacturer)Runway centreline survey referenceTorque wrench for top-plate fixings

Safety Precautions

LOTO the circuit before adjusting or removing the fixture for realignment.
Coordinate any realignment work requiring fixture removal through the same airside access and runway closure process as other RCL maintenance.

Diagnostic Procedure

ObservationConfirm the alignment issue via a night inspection from the design approach direction, comparing the affected fixture's apparent brightness against neighbours.
MeasurementCheck fixture level/inclination against the manufacturer's specified tolerance using an inclinometer, and check azimuth orientation against the base can index/keyway if fitted.
ObservationInspect the pavement immediately around the fixture for settlement, cracking, or resurfacing overlay that may have changed the reference level.
DecisionFixture rotated/mis-torqued but base can position correct → realign and re-torque the fixture. Base can itself out of position or level → this is a civil/installation defect requiring wider correction.
Fault LocationIsolate to fixture orientation/level within a correctly positioned base can, or to the base can/pavement reference itself.
Root CauseConfirm the corrected alignment restores the design beam pattern from the intended sightline.

Test Points

Fixture level/inclination vs. specification

Fixture azimuth vs. base can index

Surrounding pavement level/condition

Comparative apparent brightness vs. neighbouring fixtures

Root Cause Verification

Re-inspect from the design sightline at night after realignment, and confirm the fixture remains correctly oriented after the next scheduled maintenance interval (checking that torque has held).

Corrective Action

Realign and re-torque the fixture to the correct level and azimuth.
Shim or adjust the fixture mounting if pavement settlement has changed the reference level.
Escalate to civil works if the base can itself is incorrectly positioned.

Preventive Action

Torque-check fixture top plates as part of the periodic maintenance schedule.
Coordinate with civil/pavement teams before and after any resurfacing work near RCL fixtures to verify alignment is preserved.
Include a beam-alignment spot-check in the periodic night inspection.

Related References

SOP: SOP-RCL-09 (Fixture Alignment Verification Procedure)

Standards: ICAO Annex 14 Vol I Appendix 2 (light beam characteristics), FAA AC 150/5340-30

Diagram: RCL Fixture Installation and Alignment Drawing

Case Study: Division 26 — Photometric & Intensity Compliance

Rev 0 — Initial issue

RCL-203 Centreline Light Fixture Damage

Symptom — The fixture body, top plate, or frangible coupling is found physically damaged — cracked, deformed, or partially sheared — typically from jet blast, snow removal equipment, vehicle contact, or aircraft overrun of the fixture.

Equipment / System

RCL fixture housing, top plate, and frangible mounting coupling.

Possible Causes

HighDirect impact from a snow plough blade, sweeper, or other airside vehicle passing over or too close to the fixture

HighFrangible coupling activated (as designed) by an aircraft wheel load, or by a heavy vehicle exceeding the coupling's intended load path

MediumJet blast erosion or repeated thermal/mechanical stress cracking the housing over time

MediumCorrosion-weakened housing failing under normal operational loading

LowManufacturing or installation defect in the housing or coupling

Required Tools

Visual inspection kitTorque wrench and fixture-specific toolingReplacement fixture body/frangible coupling assembly, correct part numberBase-can lifting tool

Safety Precautions

LOTO the circuit before removing a damaged fixture.
Treat a sheared frangible coupling as having potentially left live conductors exposed at the base can — verify de-energised and inspect carefully before further handling.
Coordinate FOD sweep of the immediate area after fixture damage, as debris may be present on the runway surface.

Diagnostic Procedure

ObservationDocument the extent and apparent cause of physical damage, photographing for the maintenance and incident record.
MeasurementWith the circuit isolated, check the condition of the base-can wiring and connector, since fixture damage often accompanies connector or cable disturbance.
ObservationConfirm whether the frangible coupling has functioned as designed (clean shear at the intended break point) or whether damage extends into the base can itself.
DecisionFrangible coupling sheared cleanly, base can and wiring intact → straightforward fixture replacement. Damage extends to base can or wiring → treat as a more extensive repair, sequence with RCL-192/199 as needed.
Fault LocationIsolate the damage to the fixture body/top plate, the frangible coupling, or damage extending into the base can.
Root CauseWhere damage is impact-related and not a designed frangible activation, report to airfield operations for follow-up on the cause (vehicle, snow equipment, etc.).

Test Points

Frangible coupling condition — clean break vs. extended damage

Base-can wiring and connector integrity

Insulation resistance post-damage

Surrounding pavement/FOD condition

Root Cause Verification

After fixture replacement, confirm correct electrical operation (megger and functional test) and correct alignment before returning the section to service, and complete an FOD sweep of the area.

Corrective Action

Replace the damaged fixture body and/or frangible coupling assembly.
Repair any base-can wiring or connector damage found.
Realign the replacement fixture per RCL-202 as part of the installation.

Preventive Action

Investigate recurring fixture damage on a given section for an operational cause (vehicle routing, snow-clearing technique) rather than treating each as an isolated fixture fault.
Maintain fixture and frangible coupling spares on hand given the safety-critical, weather-dependent nature of this fault type.
Include frangible coupling condition in the periodic visual inspection.

Related References

SOP: SOP-RCL-03 (Fixture Replacement Procedure), SOP-RCL-10 (Frangible Coupling Inspection)

Standards: FAA AC 150/5345-46 (L-852 frangibility requirements), ICAO Annex 14 Vol I

Diagram: RCL Fixture and Frangible Coupling Assembly Drawing

Case Study: Division 27 — FOD & Physical Damage Case Studies

Rev 0 — Initial issue

RCL-204 Centreline Light Connector Failure

Symptom — The L-823 secondary connector between the isolation transformer and the fixture (or between the primary cable and the transformer) is found failed — corroded, cracked, arced, or not maintaining a reliable connection.

Equipment / System

L-823 primary and secondary connectors within the RCL base can.

Possible Causes

HighWater ingress into the connector body leading to corrosion and increased contact resistance

HighConnector not fully mated or seated during a previous installation or maintenance visit

MediumConnector boot/seal perished or damaged, allowing moisture and contamination in over time

MediumArcing damage from a marginal connection that has been carrying current under partial contact for an extended period

LowWrong connector type or rating fitted, mismatched to the cable/fixture combination

LowPhysical damage to the connector body from being pinched or crushed during base-can work

Required Tools

L-823 connector test adaptor1000V insulation resistance testerDielectric greaseReplacement connector, correct type and ratingTorque/crimp tool as specified by connector manufacturer

Safety Precautions

LOTO the circuit before disconnecting or inspecting any connector.
Treat a connector showing arc/heat damage as a sign of a fault that may have been present for some time — inspect adjacent components for related damage before re-energising.

Diagnostic Procedure

ObservationWith the circuit isolated, open the base can and visually inspect the connector for corrosion, cracking, arc marks, discolouration, or an incompletely mated condition.
MeasurementMegger across the connector and check continuity/contact resistance if a suitable test adaptor is available.
ObservationInspect the connector boot/seal for damage and check whether water was present in the base can (cross-reference RCL-199).
DecisionConnector shows corrosion/arc damage or fails a contact-resistance check → replace. Connector appears sound but was simply not fully mated → reseat correctly with fresh dielectric grease and re-test.
Fault LocationIsolate to the primary-side or secondary-side connector, and to the connector itself versus the boot/seal.
Root CauseConfirm the corrected connection holds under a follow-up inspection, particularly after the next significant rain event if water ingress was implicated.

Test Points

Connector contact resistance/continuity

Insulation resistance across the connector

Boot/seal condition

Base-can water presence

Root Cause Verification

Re-test insulation resistance and contact integrity after reconnection, and schedule a follow-up check after the next wet-weather period to confirm the seal is holding.

Corrective Action

Replace the failed connector with the correct type and rating.
Reseat and re-grease a connector found simply mismated.
Replace a perished boot/seal even if the connector body itself is serviceable.

Preventive Action

Apply dielectric grease at every connector mating as standard practice, not only when a fault is found.
Include connector contact-resistance checks in the periodic maintenance programme.
Stock the correct connector types and boots as standard spares given how frequently this fault type recurs across a large RCL system.

Related References

SOP: SOP-RCL-01 (RCL Fault Isolation Procedure), SOP-RCL-11 (Connector Maintenance Procedure)

Standards: FAA AC 150/5345-26 (L-823 connectors), ICAO Annex 14 Vol I

Diagram: RCL Base-Can Wiring Detail Drawing

Case Study: Division 25 — Field Case Study Troubleshooting

Rev 0 — Initial issue

RCL-205 Centreline Light Transformer Failure

Symptom — The individual isolation transformer feeding an RCL fixture has failed — open-circuit, short-circuit, or significantly out of tolerance on secondary output — distinct from a fixture lamp/LED or connector fault.

Equipment / System

RCL series-circuit isolation transformer (typically 30W/45W/65W class, matched to the fixture's lamp/LED rating).

Possible Causes

HighWinding failure from age-related insulation breakdown, particularly in transformers exposed to repeated water ingress

HighInternal short circuit from moisture tracking across the windings

MediumThermal damage from prolonged operation at a mismatched (too high) wattage rating for the fitted lamp/LED module

MediumPhysical/impact damage to the transformer body or leads during base-can work

LowManufacturing defect or a transformer that was already marginal at installation

LowCascading damage from a nearby lightning strike or major surge event on the series circuit

Required Tools

1000V/2500V insulation resistance testerTrue-RMS multimeterClamp-on ammeterReplacement transformer, correct wattage/tap ratingBase-can lifting tool

Safety Precautions

LOTO the circuit before disconnecting or removing any transformer.
Handle a transformer suspected of internal arcing carefully — do not assume it is fully de-energised even after the circuit is isolated, until tested.

Diagnostic Procedure

ObservationConfirm via CCR/ALCMS and a runway inspection that the fault pattern (single dark light, no downstream effect on the loop) is consistent with a fixture-level transformer fault rather than a cable fault (cross-reference RCL-193).
MeasurementWith the circuit isolated, disconnect the transformer at both primary and secondary connectors and megger primary-to-earth, secondary-to-earth, and primary-to-secondary.
ObservationInspect the transformer body for physical damage, discolouration, or evidence of internal arcing/overheating.
MeasurementConfirm the transformer's wattage/tap rating matches the design specification for the fitted lamp/LED module.
DecisionTransformer fails insulation test or shows physical damage → replace. Transformer tests good but wattage/tap mismatched to the fixture → replace with correctly rated unit even though the current one has not fully failed.
Fault LocationConfirm the transformer itself as the fault, distinct from the connector (RCL-204) or fixture lamp/LED (RCL-192).
Root CauseBench-test the removed transformer if practical to confirm the specific failure mode for the maintenance record.

Test Points

Transformer primary winding insulation resistance

Transformer secondary winding insulation resistance

Primary-to-secondary insulation resistance

Transformer wattage/tap vs. design specification

Root Cause Verification

After replacement with the correctly rated transformer, re-energise and confirm the fixture operates correctly across all intensity steps, and re-check insulation resistance at the next scheduled maintenance visit.

Corrective Action

Replace the failed transformer with a correctly rated unit.
Correct a wattage/tap mismatch even where the existing transformer has not yet fully failed.
Address any water ingress found in the base can (cross-reference RCL-199) to prevent recurrence.

Preventive Action

Include transformer insulation resistance testing in the periodic PM programme, trending results to catch degrading units before failure.
Verify wattage/tap rating against the design specification at every transformer replacement.
Maintain correctly rated transformer spares on hand, given the range of wattages used across a typical RCL system.

Related References

SOP: SOP-RCL-01 (RCL Fault Isolation Procedure), SOP-RCL-12 (Transformer Test and Replacement Procedure)

Standards: FAA AC 150/5345-26 (L-823/isolation transformers), ICAO Annex 14 Vol I

Diagram: RCL Circuit Design Specification

Case Study: Division 01 — CCR Troubleshooting (series circuit fundamentals)

Rev 0 — Initial issue

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Frequently Asked Questions

Quick answers about Runway Centreline Light (RCL) troubleshooting in the AGL Troubleshooting Atlas.

Q1What does Division 05 of the AGL Troubleshooting Atlas cover?

Division 05 is the Runway Centreline Light (RCL) Troubleshooting reference. It publishes 15 diagnostic topics, RCL-191 to RCL-205, for Runway Centreline Light (RCL) faults on airfield ground lighting systems.

Q2What information does each topic include?

Every topic follows the same diagnostic record: the symptom, equipment/system, possible causes ranked by likelihood (high, medium or low), required tools, safety precautions, diagnostic procedure, test points, root cause verification, corrective action, preventive action and related references (SOPs, standards, diagrams and case studies).

Q3Which Runway Centreline Light (RCL) faults are covered?

The 15 topics are RCL-191 to RCL-205: Runway Centreline Light Not Working; Single Centreline Light Failure; Multiple Centreline Light Failure; Centreline Light Flickering; Centreline Light Dim; Centreline Light Incorrect Color; Centreline Light Wrong Intensity; Centreline Light Optical Failure; Centreline Light Water Ingress; Centreline Light Lens Damage; Centreline Light Prism Damage; Centreline Light Alignment Error; Centreline Light Fixture Damage; Centreline Light Connector Failure; Centreline Light Transformer Failure.

Q4How does a diagnostic procedure begin in Division 05?

Each procedure starts with observation before any intervention. For example, RCL-191 (Runway Centreline Light Not Working) begins: Check the ALCMS/CCR panel to see whether this is reported as a single light or part of a wider dark section, and confirm the actual current output of the affected RCL series circuit.

Q5What safety precautions apply when troubleshooting Runway Centreline Light (RCL)?

Each topic lists its own precautions. For example, RCL-191 (Runway Centreline Light Not Working) starts with: Coordinate all airside access through ATC/airfield operations and obtain a runway closure or inspection slot before approaching the light.

Q6Which SOPs are referenced in Division 05?

Related references in the topics include SOP-RCL-01 (RCL Fault Isolation Procedure), SOP-CCR-04 (CCR LOTO Procedure), SOP-RCL-03 (Fixture Replacement Procedure), SOP-RCL-02 (Series Circuit Fault Location Procedure), SOP-RCL-04 (Lens Cleaning and Inspection Procedure), SOP-RCL-05 (Colour-Zone Verification Procedure), SOP-CCR-08 (Intensity Step Verification) and SOP-RCL-06 (Optical Assembly Inspection Procedure), and 6 more.

Q7Which standards are referenced in the Runway Centreline Light (RCL) topics?

Where a standard applies, it appears in the topic's Related References. Those cited in this division include ICAO Annex 14 Vol I, FAA AC 150/5340-30, FAA AC 150/5345-46, FAA AC 150/5345-26, IEC 60364 and ICAO Annex 14 Vol I Appendix 2.

Q8How can I find a specific fault in Division 05 quickly?

Use the search box at the top of the page to filter the 15 published topics by code, fault name or keyword; matching topics open automatically. Each diagnostic record can also be downloaded as a Word (.doc) file.