150-5340-26c Airfield Lighting.pdf

U.S. Department of Transportation

Federal Aviation Administration

Advisory Circular

Subject: Maintenance of Airport Visual Aid Facilities

Date: 6/20/2014 Initiated by: AAS-100

AC No: 150/5340-26C Change:

1. Purpose. This advisory circular (AC) provides recommended guidelines for maintenance of airport visual aid facilities.

2. Applicability. The Federal Aviation Administration (FAA) recommends the guidance and specifications in this AC for the Maintenance of airport Visual Aid Facilities. In general, use of this AC is not mandatory. However, use of this AC is mandatory for all projects funded with federal grant monies through the Airport Improvement Program (AIP) and with revenue from the Passenger Facility Charges (PFC) Program. See Grant Assistance No. 34, Policies, Standards, and Specifications, and PFC Assurance No. 9, Standards and Specifications.

3. Cancellation. This AC cancels AC 150/5340-26B, Maintenance of Airport Visual Aid Facilities, dated September 30, 2009.

4. Principal Changes. General grammatical and format changes to break up large sections and to facilitate easier reading.

a. Paragraph 2.0 has an added section to better introduce the concept of safety.

b. Paragraph 2.2 – a new section is added to be in better alignment with the personnel safety requirements in National Fire Protection Association (NFPA) 70E, Standard for Electrical Safety in the Workplace.

c. Paragraph 2.4.1.1 is added for arc flash protection description.

d. Figure 2-1 is added to show an example of an arc flash warning label.

e. Paragraph 3.2.1 is added to describe maintenance log requirements for PAPI, VASI, and

ODALS.

f. Paragraph 3.7 is added to describe what to do when visual aids are implicated in an aircraft accident. Procedures are also furnished for actions to be taken when a visual aid that was previously NOTAM is restored to service.

g. Paragraph 5.3.4 is expanded to add requirements for bolt torque and explain one-time bolt use for in-pavement light fixtures.

h. Paragraph 5.11 – removed “hazard beacons” and added note.

AC 150/5340-26C 6/20/2014

i. Paragraph 5.15, Omnidirectional Approach Lighting System (ODALS), is added.

j. Appendix B is added: Maintenance Log Preparation Guide.

Michael O'Donnell Director of Airport Safety and Standards ii

6/20/2014 AC 150/5340-26C

iii

Table of Contents

Chapter 1. Introduction

1.0 General

1.1 Scope

1.2 Applicable Documents

Chapter 2. Safety

2.0 General

2.1 Common Causes of Accidents

2.2 Safety Requirements

2.3 Safety Procedures and Guidelines

2.4 Electrical Hazards of Series Lighting Circuits

2.5 Safety Practices

2.6 Safety Boards

2.7 Safety Checklist

2.8 Safety Equipment in Vehicles

2.9 Electric Shock

2.10 Safety Training

2.11 Safety Warning Signs/Danger Tags

2.12 Grounding and Bonding

2.13 Confined Spaces

2.14 Lightning

2.15 Toxic Agents

2.16 Fire Extinguishers

2.17 First Aid

Chapter 3. Maintenance Management

3.0 Maintenance Philosophy

3.1 Maintenance Schedule

3.2 Maintenance Records

3.3 Preventive Maintenance Program

3.4 Record Retention

3.5 Reference Library

3.6 Spare Part Provisioning

3.7 When Lighted Navigational Aids are Identified as Suspect in an Aircraft Accident. .29

Chapter 4. Test Equipment

4.0 Introduction

4.1 Types of Equipment and Usage

Chapter 5. Preventive Maintenance

5.0 General

5.1 Airport Lighting Vault

5.2 Constant Current Regulators (CCRs)

5.3 Light Fixture and Base Maintenance

5.4 Illuminated Runway and Taxiway Guidance Signs

iv

5.5 Rotating Beacons

5.6 Lighted Wind Cone Assemblies

5.7 Precision Approach Path Indicator (PAPI) System

5.8 Visual Approach Slope Indicator (VASI)

5.9 Runway End Identifier Lights (REILs)

5.10 Medium Approach Lighting System (MALS, MALSF, MALSR)

5.11 Obstruction Lights

5.12 Airport Lighting Control and Monitoring Systems (ALCMS)

5.13 Runway Status Lights (RWSL)

5.14 Standby and Emergency Power Systems

5.15 Omnidirectional Approach Lighting System (ODALS)

Chapter 6. Troubleshooting Procedures for Series Lighting Circuits

6.0 Initial Fault Investigation – Safety

6.1 Locating Ground Faults in the Field

6.2 Locating Open Circuit Faults

6.3 Interconnected Circuit Faults

6.4 Intentional Ground Test

6.5 Grounded Output Test for Locating Open Circuits

6.6 Using Heat Sensing Equipment to Locate Ground Faults

6.7 Using Cable Fault Locating Equipment to Locate Ground Faults

Appendix A. Standards and Tolerances

Appendix B. Maintenance Log Preparation Guide

List of Figures

Figure 2-1. An Arc Flash Warning sign Figure 2-2. Example of a “Danger – High Voltage” sign Figure 2-3. Examples of Danger Tags Figure 5-1. Sample Insulation Resistance Record Figure 5-2. Cleaning Runway Centerline and Touchdown Zone Lights Figure 5-3. PAPI Configuration Figure 5-4. REIL Layout Figure 5-5. REIL Aiming Figure 5-6. MALSR Configuration Figure 5-7. Light Fixtures Inoperative Requiring THL Shutdown Figure 6-1. Typical Series Lighting Circuit Figure 6-2. Typical Ground Faults Figure 6-3. Locating Ground Faults with the VOM Figure 6-4. Alternative Method of Finding Ground Fault Using VOM or Insulation Resistance

Tester Figure 6-5. Locating Open Circuit Faults Figure 6-6. Single Load-to-Load Fault v

Figure 6-7. Two Load-to-Load Shorts Figure 6-8. Intentional Ground Test Figure 6-9. Intentional Ground Preventive Maintenance Tool Figure 6-10. Grounded Output Test Figure 6-11. Dangerous Isolation Transformer/Circuit Ground Faults

List of Tables

Table 5-1. Preventive Maintenance Inspection Schedule for Airport Lighting Vaults Table 5-2. 3-Step CCR Output Tolerances Table 5-3. 5-Step CCR Output Tolerances Table 5-4. Preventive Maintenance Inspection Schedule for Constant Current Regulators Table 5-5. Preventive Maintenance Inspection Schedule for Runway and Taxiway Elevated

Edge Lights Table 5-6. Preventive Maintenance Schedule for In-pavement Runway and Taxiway Lighting 65 Table 5-7. Preventive Maintenance Schedule for Rotating Beacons Table 5-8. Preventive Maintenance Schedule for Lighted Wind Cones Table 5-9. Preventive Maintenance Schedule for PAPI (Precision Approach Path Indicator) ... 77 Table 5-10. Preventive Maintenance Schedule for VASI (Visual Approach Slope Indicator) ... 81 Table 5-11. Preventive Maintenance Schedule for REIL (Runway End Identifier Lights) Table 5-12. Preventive Maintenance Schedule for MALSR (Medium Intensity Approach Light

System with Runway Alignment Lights) Table 5-13. Preventive Maintenance Inspection Schedule for Hazard Beacons and Obstruction

Lights Table 5-14. Quarterly and Annual Preventive Maintenance Checklist for Standby Generator Sets

Table 5-15. Preventive Maintenance Schedule for ODALS (Omni directional Approach Light

System) vi

Intentionally Left Blank

Chapter 1. Introduction.

1.0 General.

This Advisory Circular (AC) provides guidance for the recommended minimum maintenance practices to be used for the maintenance of airport visual aid facilities. Although this AC provides the minimum requirements for establishing a maintenance program, due to the varying complexities of individual airports and the visual aids facilities provided, the program must be tailored to suit each airport’s particular needs. Use this AC with the information available in manufacturer’s instruction books, equipment manuals, handbooks and other ACs.

Because the function of airport visual aid facilities is to assist in the safe and efficient movement of aircraft during landing, takeoff and taxiing maneuvers, it is essential that a high degree of operating reliability be maintained. To achieve this, an effective preventative maintenance program must be established and maintained. This AC provides suggestions about establishing a program but, due to the varying complexities of airports and the visual aids facilities provided, the program must be tailored to suit each airport’s particular needs.

Because corrective and preventive maintenance procedures for specific equipment are usually covered in instruction manuals supplied with the equipment, this AC will address maintenance topics of a more general nature.

1.1 Scope.

This AC provides system maintenance information for establishing a preventive maintenance program for airport visual aid facilities. The information provided is for the following systems:

• Airport lighting vault and series lighting circuits

• Constant current regulators

• Runway and taxiway elevated edge lighting systems

• Runway and taxiway in-pavement lighting systems

• Runway guard lights and stop bar lights

• Illuminated runway and taxiway signs

• Rotating beacons

• Lighted wind cone assemblies

• Precision Approach Path Indicator (PAPI) system

• Visual Approach Slope Indicator (VASI)

• Runway End Identifier Lights (REIL) and Omni directional Approach Light System

(ODALS)

• Medium Intensity Approach Light System (MALS, MALSF, MALSR)

• Airfield Lighting Control and Monitoring system (ALCMS)

• Runway Status Lights (RWSL)

• Obstruction lights

• Control systems

• Standby power engine generator systems

In addition to equipment topics, this AC also recommends safety practices and troubleshooting procedures for airport series lighting circuits.

1.2 Applicable Documents.

1.2.1 National Fire Protection Association (NFPA).

• NFPA 10, Standard for Portable fire Extinguishers

• NFPA 70E, Standard for Electrical Safety in the Workplace

NFPA documents may be obtained (not free of charge) at:

www.nfpa.org/catalog/category.asp?category_name=NFPA+70E

1.2.2 Occupational Safety and Health Administration (OSHA).

• General Industry Safety-Related Work Practices – 29 CFR 1910

OSHA documents may be obtained at:

https://www.osha.gov/pls/oshaweb/owastand.display_standard_group?p_toc_level=1&p_part_nu mber=1910

1.2.3 American Society for Testing and Materials (ASTM).

• ASTM D120, Specification for Insulated Rubber Gloves

ASTM specifications may be obtained via standard mail from:

American Society for Testing and Materials 1916 Race Street Philadelphia, PA 19103.

Specifications may also be purchased and downloaded (charges may apply) from the internet at:

webstore.ansi.org/SdoInfo.aspx?sdoid=41&Acro=ASTM&DpName=ASTM%20International&s ource=googe&keyword=astm&gclid=CPuey-Sy1boCFe5cMgodMi0AIA

1.2.4 Federal Aviation Administration (FAA) Advisory Circulars (AC).

• AC 150/5210-5, Painting, Marking, and Lighting of Vehicles Used on an Airport

• AC 150/5210-20, Ground Vehicle Operations on Airports

• AC 150/5340-30, Design and Installation Details for Airport Visual Aids

• AC 150/5345-46, Specification for Runway and Taxiway Light Fixtures

FAA ACs may be downloaded at: www.faa.gov/airports/resources/advisory_circulars/ http://www.nfpa.org/catalog/category.asp?category_name=NFPA+70E https://www.osha.gov/pls/oshaweb/owastand.display_standard_group?p_toc_level=1&p_part_number=1910 https://www.osha.gov/pls/oshaweb/owastand.display_standard_group?p_toc_level=1&p_part_number=1910 http://webstore.ansi.org/SdoInfo.aspx?sdoid=41&Acro=ASTM&DpName=ASTM%20International&source=googe&keyword=astm&gclid=CPuey-Sy1boCFe5cMgodMi0AIA http://webstore.ansi.org/SdoInfo.aspx?sdoid=41&Acro=ASTM&DpName=ASTM%20International&source=googe&keyword=astm&gclid=CPuey-Sy1boCFe5cMgodMi0AIA

1.2.5 FAA Engineering Briefs (EB).

• FAA EB 83, In-pavement Light Fixture Bolts

FAA EBs may be downloaded at: www.faa.gov/airports/engineering/engineering_briefs/

1.2.6 Federal Aviation Administration (FAA) Joint Orders (JO).

• JO 7930.2, Notices to Airmen (NOTAM)

May be obtained at: http://www.faa.gov/documentLibrary/media/Order/NTM.pdf http://www.faa.gov/airports/engineering/engineering_briefs/ http://www.faa.gov/documentLibrary/media/Order/NTM.pdf

Chapter 2. Safety.

2.0 General.

This chapter provides information that will aid airport owners/operators in establishing an effective safety program. Safety is the responsibility of everyone and must be practiced in every maintenance activity that is performed. Any additional local operational procedures and OSHA requirements should also be followed. The safety program established at each airport should include preventive safety precautions used when servicing the equipment and first-aid procedures for use in the event of an injury.

We are all surrounded by various hazards every day such as the careless driver using a cell phone that we see on our way to work. Safety is everyone’s responsibility and our own responsibility.

We cannot delegate our safety responsibilities to others. It is our responsibility to set the safety example for others. Safe work practices is a learned attitude and skill we should be passing on to our fellow workers and our family.

Safety is no accident. Know and comply with your company’s safety program and lockout/tagout procedure. Use and store personal protective equipment (PPE) properly. Verify that your test equipment functions properly. Become familiar and knowledgeable with National Fire Protection Association (NFPA) 70E, Standard for Electrical Safety in the Workplace.

Should a conflict between your local safety plan and this document occur, we recommend adherence to the stricter (safer) requirement.

THINK SAFETY FIRST!

2.1 Common Causes of Accidents.

Some common causes of accidents are listed below:

a. Working on equipment without adequate coordination with equipment users.

b. Working on equipment without sufficient training or experience.

c. Failure to follow instructions in equipment manuals.

d. Failure to follow safety precautions.

e. Failure to properly lock and tag out equipment.

f. Using unsafe equipment.

g. Becoming lax due to working in a familiar environment.

h. Poor housekeeping of work areas.

i. Working in a hurried manner.

The number one cause of accidents is working in a hurried manner. It is often the main contributing factor in failing to follow proper safety guidelines in all the other causes outlined in the list above. The perception that there is not enough time to take proper safety precautions or think through the proper procedures has a high potential for causing an accident. When in emergency repair situations, maintenance personnel must be careful to follow proper safety procedures to avoid the possibility of injury or death.

2.2 Safety Requirements.

Only a qualified person, per the definition in NFPA 70E, performs maintenance work. The qualified person must possess the requisite technical skills and be trained to recognize and avoid electrical hazards. The qualified person must also be trained in the proper procedures for operations in an aircraft operation area (AOA). A person may be considered qualified for certain tasks and not qualified for others.

2.2.1 Qualified Person.

A qualified person must, at a minimum, be additionally trained to:

• Distinguish exposed live parts from other parts.

• Determine nominal voltage of exposed parts.

• Determine the approach distances in NFPA 70E; Table 130.2(C).

• Possess the decision-making skills necessary to determine the degree and extent of hazard, PPE required and planning to safely perform the job.

2.2.2 Hazard/Risk Evaluation.

Perform a Hazard/Risk evaluation of the task to be accomplished. For an example of a Hazard/Risk procedure, refer to NFPA 70E, Annex F.

When performing repetitive tasks we tend to take safety for granted. Do not let familiarity with the task provide a false sense of security. A task performed 100 times unsafely without an injury is still unsafe.

2.2.3 Job Set-up.

Before starting each task, review the following basic items:

a. Hazards associated with the work.

b. Safe work procedures and any special precautions.

c. Energy source controls.

d. PPE requirements.

2.2.4 Electrically Safe Work Condition.

Energized parts or components that an employee may be exposed to must be put into an electrically safe work condition before an employee works on or near them. Electrical components must be considered to be energized until the source(s) of energy is (are) removed, at which time they must be de-energized. In addition, remove all other sources of energy or stored energy – capacitors, pneumatic, steam, chemical, springs, gravity, jet blast, etc.

a. Determine all sources of energy to the equipment.

b. Turn off the equipment using proper controls; open the disconnecting means for each electrical source.

c. When possible, visually verify all blades of the disconnecting device are fully open and/or draw-out type circuit breakers are withdrawn to the fully open position.

d. Verify all other energy sources have been identified and turned off, removed, blocked or secured as required to safely and properly control the specific energy source.

e. Apply lockout/tagout devices per documented and established policy.

f. Use an adequately rated volt meter to test phase-to-phase and phase-to-ground for voltage. Before and after the test, verify proper operation of the test equipment.

g. Where the possibility of induced voltages or stored electrical energy exists, ground the phase conductors or circuit parts. If components could become reenergized use grounds that can withstand fault currents.

h. Only when the previous seven steps (2.2.4a through 2.2.4g) are successfully completed, is it possible to create an Electrically Safe Work Condition.

2.2.5 Electrically Unsafe Work Condition.

An electrically unsafe work condition is defined as “working on or near live parts of 50 volts or more.” The word, “near” is defined as “within the limited approach boundary provided by NFPA 70E, Table 130.4(C) and Table 130.4(C)(b).” To perform work on or near live parts of 50 volts or more, the following steps must be accomplished:

a. Justification – Demonstrate that de-energizing introduces additional or increased hazards or is not feasible due to equipment design or operational limitations. (see NFPA 70E, Section 130.2)

b. Complete an energized work permit that authorizes work on energized equipment.

c. Perform an electrical hazard analysis consisting of:

1. A shock hazard analysis to determine the voltage(s) to which personnel will be exposed, boundary requirements and the personal protective equipment (PPE) necessary to minimize the possibility of electric shock to personnel.

2. A flash hazard analysis must be completed to protect personnel from the possibility of being injured by an arc flash. The analysis determines the flash protection boundary and the PPE that personnel within the flash protection boundary must use.

d. Implement the requirements of the shock and flash hazard analysis prior to starting any work.

e. Complete the work safely and return the system to safe operating status.

f. Close out the energized equipment work permit.

2.3 Safety Procedures and Guidelines.

Most airport visual aid equipment is exposed to weather and may develop electrical shock hazards through damage from lightning or electrical cable insulation deterioration from exposure. Begin maintenance procedures only after a visual inspection is made for possible hazards. Due to the hazards associated with lightning, lighted navigational aids should not be serviced during periods of local thunderstorm activity. Each airport should develop and implement procedures to be followed in the event of an accident. Precious seconds are saved rendering medical assistance to injured personnel when action plans are already in place.

Rehearse and review action plans regularly.

2.4 Electrical Hazards of Series Lighting Circuits.

Airport lighting circuits are very dangerous. This is especially true for maintenance personnel with little or no experience working on constant current series circuits. Airport lighting circuits can operate at potentials of several thousand volts depending on the size of the regulator driving the circuit and the load.

2.4.1 Basic Rules.

There are three basic rules to remember when working on and around airport lighting circuits:

a. ALWAYS assume that the circuit is energized until you have proven otherwise.

ALWAYS check for current before disconnecting the series circuit connector, removing the S1 cutout, or opening the primary series circuit by any other means. Make it a required practice to check the circuit with an ammeter prior to breaking the connection – NO EXCEPTIONS. Never attempt to measure voltage in a series lighting circuit using ordinary volt meters. An inductive voltage measuring device (sometimes referred to as a “ticker”) such as is described in Chapter 4 may be used to detect the presence of induced voltage on a series lighting cable after checking for the presence of current. Always use a true RMS clamp-on type ammeter to verify if the circuit is energized. ALWAYS check the operation of the test equipment on a known live circuit before and after measurements are taken.

b. NEVER under any circumstances open or break a live airfield series circuit. The voltage generated in the circuit can reach levels many times normal before the regulator’s open circuit protection can shut it down. As long as a current flow can be maintained, even if it is through you, the regulator will continue to operate. This is one of the reasons that series circuits can be so hazardous to work around - there is no personnel protection provided such as might be found on parallel interior wiring.

c. NEVER enter a manhole with energized conductors and never handle cables or transformers in light bases while there is current present. Cables or connectors can have cracked insulation where it is not visible or may be deteriorated and fall apart, exposing you to live circuit conductors.

2.4.2 Induced Voltages.

Series circuits are typically run from the lighting vault in duct banks where the wires are lying parallel to each other in close proximity. Voltages may be induced in an otherwise un-energized conductor and may be a hazard when troubleshooting and testing. Circuits that have a load that varies due to flashing action of runway guard lights or REIL strobes are particularly prone to induce voltages in other conductors due to the pulsing characteristics of the voltage and current in these circuits. Always remember that there may be a possibility of an induced voltage in any conductor. Never work on or in close proximity to live circuits within any duct or manhole.

2.4.3 Re-lamping.

The most common lighting maintenance task on the airfield is re-lamping of incandescent runway and taxiway lighting fixtures.

Note: See paragraph 5.3.2 for information about light emitting diode (LED) light fixtures.

Depending on the type of light fixture, this may be accomplished in the field or, in the case of most in-pavement lights, the entire light fixture is removed, replaced, and brought to the maintenance shop for refurbishing. The greatest unseen danger to you is re-lamping or removing the fixture with the circuit energized. This has always been a common practice by airport electricians for convenience and the dangers are often overlooked. There are two primary hazards associated with this practice:

a. The first hazard occurs when there is a short circuit between the isolation transformer primary and secondary windings. Remember that isolation transformers are not designed for personnel protection. They are designed to isolate the secondary winding from the primary circuit to allow continued operation with a lamp burned out. A transformer with a primary to secondary short may not cause a circuit malfunction and could remain unnoticed during normal operation.

A short from the isolation transformer primary to secondary winding exposes you to the full voltage present on the primary circuit and can be especially dangerous if another short is present on the primary circuit. When that happens, you can become the path to ground for the full primary current, a circumstance that is almost always fatal. This condition is especially dangerous when working with inset lights and removing them from the light base while the circuit is still energized. As soon as the light fixture is unbolted and lifted from the light base, you might become the path to ground. The FAA has tried to eliminate this hazard by recommending the attachment of a ground wire from the bottom of the light fixture to a grounding lug on the inside of the light base.

Remember, you cannot know if the light fixture grounding wire is truly connected until you remove the fixture, at which time it is too late.

b. The second hazard encountered when re-lamping an energized light fixture is from the open circuit voltage present at the secondary of the isolation transformer. The open circuit voltage present on the secondary of the isolation transformer is proportional to the size of the transformer. For example, the open-circuit secondary voltage on a 300 watt transformer is approximately 110 volts. Moreover, depending on the materials used in the design of the isolation transformer and the type of regulator powering the circuit, high voltages can be generated. The larger the wattage of the isolation transformer, the higher the open circuit voltage; as much as 200 volts may be present in some circumstances.

Therefore, we recommend that you perform re-lamping of the series lighting circuits with the circuits de-energized, especially during the re-lamping of fixtures with exposed contacts.

c. A final hazard that is present when re-lamping any type of fixture, whether in the field or at the maintenance shop, is the danger of cuts from broken lamps. Many times when an airfield lamp fails, the glass envelope becomes cracked or brittle and can break during the removal process. Always wear leather gloves when removing lamps to prevent your hands from being cut in the event that a lamp shatters.

2.5 Safety Practices.

When you perform maintenance on airport visual aids, use the following safety practices:

a. Ensure that all maintenance workers are trained and familiar with electrical safety.

b. Strictly observe all safety rules.

c. Ensure that all test equipment is listed by a third party testing laboratory and properly rated for the voltage under test and the intended application.

d. Prior to beginning any maintenance work on airport lighting circuits, coordinate the work schedule with the air traffic control tower, facility manager, or airport operations personnel. Make sure circuits will not be energized during maintenance by observing strict lock-out tag-out procedures for the equipment and obtain authorization for local control if equipment is normally operated via remote control.

e. Where maintenance is to be conducted on a high-voltage circuit, assign at least two electricians, with at least one having a thorough knowledge of the layout of all airport high-voltage circuits.

f. Because performing maintenance on many airport visual aids requires workers to traverse the active airfield, all workers must be fully knowledgeable of air traffic control and radio communication procedures. Workers must also be familiar with airport runway and taxiway layouts to avoid the possibility of runway incursions. All air traffic control instructions must be read back to the controller and, if the worker has any question regarding the instructions of the controller, the worker must ask the controller to repeat the message. All vehicles operated within the aircraft operations area (AOA) must be properly marked and lighted per FAA AC 150/5210-5, Painting, Marking and Lighting of Vehicles Used on an Airport.

If you are designated as an observer electrician, your duties include:

• Keeping other personnel not involved in the work clear of the equipment.

• Being familiar with power disconnects and immediately disconnecting the power source in case of emergency.

• Being qualified in first-aid and prepared to render emergency care if necessary. You should keep in mind that prevention of an electrical accident is of primary importance though first-aid treatment is available.

• Observing the work being done to detect and prevent unsafe practices.

2.5.1 Personal Safety Precautions.

Every electrician should use the following safety precautions:

a. Know the location of main power disconnect devices.

b. Know how to summon medical aid.

c. De-energize circuits by removing the proper fuses using insulated fuse pullers or by turning off and locking out circuit breakers or other disconnecting means. Consult circuit diagrams to identify all fuses, breakers or disconnects involved. Remember that removal of a fuse does not remove the voltage from the “hot” fuse clip. Discharge all capacitors.

d. Do not depend on interlocks to remove power or on indicating lights to signal that power is off. Verify that power is off by using a voltmeter and/or ammeter on the component after opening the power switch. Verify operation of voltmeter (or ammeter) on known live circuit before and after measurements are taken.

e. Insulate your feet by standing on a dry rubber mat. Remember, however, that any contact with the grounded equipment cabinet could nullify this protection.

f. Stay clear of terminals, leads, or components that carry voltages of any magnitude. Also, avoid contact with components that are grounded, including the equipment cabinet frame.

g. Shut down and de-energize the equipment when it is necessary to reach into the equipment in locations where rapid and direct withdrawal of the hand is not possible. In any case, only one hand should be exposed, with the other hand kept away from contact with voltages or ground.

h. Be certain that there is no power applied to a circuit when making a continuity or resistance check (the meter will be damaged and you could be injured).

i. Ground test equipment to the equipment under test unless otherwise specified in instruction manuals.

j. Place a warning sign, such as “DANGER - DO NOT USE OR OPERATE,” at the main switch or circuit breaker, and provide a lockout for the circuit on which you will be working. Follow direction of local facility lock-out tag-out procedures manual.

k. Do not wear jewelry, wristwatches, or rings while working with electrical equipment.

l. Keep clothing, hands, and feet dry if at all possible.

m. Use the correct tool (screwdriver, alignment tool, etc.) for doing the job.

n. Never use toxic or flammable solvents for cleaning purposes.

o. Where air pressure is required for cleaning, use a low-pressure (30 psi or less) air source.

Eye protection (goggles or face mask) is necessary when using compressed air for cleaning.

p. Do not take anything for granted when working with inexperienced help.

2.5.1.1 Arc Flash Protection. Understanding the Arc Flash Warning Labels

a. Each piece of equipment operating at 50 volts or more and not de-energized while work is being performed, must be evaluated for arc flash hazard and shock protection. This evaluation will determine the boundaries (i.e. prohibited, limited, restricted, etc.) of the arc flash and shock hazards. The evaluation will inform employees of what PPE must be worn.

b. When the evaluation is complete, an arc flash hazard warning label (see Figure 2-1) must be affixed to the equipment and be conspicuous to employees who may work on the energized equipment.

Figure 2-1. An Arc Flash Warning sign

2.6 Safety Boards.

Locate a plywood board for posting safety procedures and a pegboard for mounting safety equipment in the airport lighting vault, switchgear rooms, engine generator rooms, and other appropriate locations. In addition, provide a telephone for emergency use as well as regular communications use. Recommended safety procedures and safety items to be included on or adjacent to safety boards are as follows:

a. Accident and fire procedures.

b. Emergency telephone numbers, such as doctor, hospital, rescue squad, fire department, airport operations, police and Air Traffic Control Tower (ATCT).

c. Resuscitation instructions.

d. Resuscitation equipment (Resuscitube or equivalent).

e. First-aid kit.

f. High-voltage disconnect (hot) stick.

g. Non-conductive body rescue hook.

h. Rubber gloves rated for maximum voltage present with leather gloves and protective storage bag.

i. Insulated fuse puller.

j. Non-metallic flashlight

k. Grounding stick.

l. Safety posters and bulletins.

m. Portable non-conductive warning signs with non-conductive hangers.

n. Fire extinguisher of proper type rating for electrical fires.

o. Emergency eyewash station if not provided elsewhere in building.

p. Automatic External Defibrillator (may require certified personnel)

2.6.1 Safety Board Inspection.

Inspect the equipment located on the safety board as indicated below:

a. Test rubber gloves in accordance with ASTM D120, Specification for Insulated Rubber Gloves.

ASTM specifications may be obtained from the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103. Specifications may also be purchased and downloaded from the internet at:

http://webstore.ansi.org/SdoInfo.aspx?sdoid=41&Acro=ASTM&DpName=ASTM%20Int ernational&source=googe&keyword=astm&gclid=CPuey-Sy1boCFe5cMgodMi0AIA

b. Testing may be performed by private testing labs, utility companies, and large military and Federal establishments.

c. Gloves should be proof-tested at the following intervals:

• In daily use – 30 days.

• Infrequently used – 180 days.

d. Visually inspect hot sticks for paint smears, carbon paths, dirt smears, etc., and clean them, if required, prior to use. Re-surface and test hot sticks that cannot be cleaned and/or have significant surface-coating ruptures.

Note: Wear certified rubber gloves (ASTM D120) and protective leather gauntlets whenever hot sticks are used.

2.7 Safety Checklist.

Perform a safety inspection on a monthly basis to ensure that the safety boards contain all required items and that test equipment is in a safe operating condition. Retain the completed checklist on file for at least one year.

2.8 Safety Equipment in Vehicles.

All vehicles operated on the airfield should have a properly sized fire extinguisher and first aid kit. Equip all vehicles and/or personnel with radio communication to be available to summon help in an emergency. Mark and register all vehicles appropriately. Equip all vehicles with a lighted warning beacon (see AC 150/5210-5, Painting, Marking, and Lighting of Vehicles Used on an Airport, for additional information about airport vehicle mounted beacons).

2.9 Electric Shock.

An electric shock is the passing of an electric current through a person. The amount of damage depends on the amount of voltage and current to which the person is subjected.

a. Voltages between 200 and 1000 volts at commercial power line frequencies are particularly harmful since, under these conditions, heart muscle spasm and paralysis of http://webstore.ansi.org/SdoInfo.aspx?sdoid=41&Acro=ASTM&DpName=ASTM%20International&source=googe&keyword=astm&gclid=CPuey-Sy1boCFe5cMgodMi0AIA http://webstore.ansi.org/SdoInfo.aspx?sdoid=41&Acro=ASTM&DpName=ASTM%20International&source=googe&keyword=astm&gclid=CPuey-Sy1boCFe5cMgodMi0AIA the respiratory center occur in combination. However, lower voltages can also prove fatal, as evidenced by records of deaths caused by 32 volt farm lighting systems. The body response to current is a follows:

• 5 to 15 mA stimulates the muscles

• 15 to 19mA can paralyze the muscles and nerves through which it flows

• 25 mA and above may produce permanent damage to nerve tissues and blood vessels

• 70 mA and above may be fatal.

b. The injurious effects suffered during electric shock depend upon the path of the current through the body. The current path will take the most direct route through the body from the two points of contact. For this reason, any current path which involves the heart or the brain is particularly dangerous. Therefore, keeping one hand clear of the equipment will eliminate the possibility of a current path from arm to arm.

2.10 Safety Training.

Establish a safety training course and conduct for all employees. Conduct follow-up training on a periodic basis to ensure that employees are safety motivated. Include first aid and CPR (Cardio-Pulmonary Resuscitation) training in the safety training course. The safety course must include driver safety training (see AC 150/5210-20, Ground Vehicle Operations on Airports) and proper procedures on contacting local emergency, police, and fire agencies.

2.11 Safety Warning Signs/Danger Tags.

The following discusses the use of warning signs on high voltage equipment.

2.11.1 Warning Signs.

Permanently place “DANGER – HIGH VOLTAGE” signs on all fixed electrical equipment where potentials of 500 volts or more terminal-to-ground are exposed. Place signs in a conspicuous location, usually on the outside of the equipment.

Figure 2-2. Example of a “Danger – High Voltage” sign

2.11.2 Lock-Out/Tag-Out and Danger Tags.

Every airport electrical maintenance department must have a written lock-out/tag-out procedure.

Equipment or circuits should never be worked on unless they are locked out and tagged by the person performing the work. In these situations, make it a rule to never trust anyone but yourself. Have your partner check behind you to make sure the proper equipment is turned off.

The lock-out tag should only be removed by the person who signed it except in some circumstances when verbal permission has been granted to another person or when the worker who signed the tag is on vacation, etc. Never rely on the air traffic controllers to assure electrical safety. Air traffic controllers are relieved periodically and the next person may not know of the work that is going on.

Always take whatever time is necessary to make sure that the circuit or equipment you are working on is safe. One of the primary reasons for accidents is when workers get in too great a hurry and don’t take proper precautions and follow proper safety procedures. Always follow safety procedures and never become negligent or lax because you are doing the “same old job” on a daily basis.

Figure 2-3. Examples of Danger Tags

2.11.3 Locks and Padlocks.

Use built-in locks on switchgear and disconnecting switches whenever the equipment is tagged, and return the keys to the supervisor responsible for their control. Padlocks need not be used if it is decided that use and control of them would be difficult because of the type of switchgear and its location. However, use padlocks with “DANGER” tags attached when equipment or electrical lines remain out of service or when electrical work has been discontinued until a later date. When outside contractors are involved, each contractor should attach and control tags and locks independently.

2.12 Grounding and Bonding.

Never remove, alter, or attempt to repair conductors or conduit systems providing grounding or electrical bonding for any electrical equipment until all power is removed from equipment.

Warn all personnel of the ungrounded condition of the equipment. Display appropriate warning signs, such as danger tags, to warn personnel of the possible hazards.

2.13 Confined Spaces.

Be sure to have a plan in place for dealing with confined spaces that conforms to OSHA standards. Make sure to test the air quality and use an approved blower to ventilate any confined spaces before entering. This includes any unventilated space especially manholes and storage tanks. Remember that gases produced by rotting materials, both vegetable and animal, will displace oxygen. These materials can be commonly found in airport lighting manholes. When working in manholes and storage tanks with vertical access, personnel must wear proper Class II or Class III harnesses and be connected to a rescue tripod-mounted winch mounted above the entrance. Use forced air blowers with flexible ducts to provide fresh air to confined spaces.

Keep vehicles away from air intakes for blowers. Vehicle exhaust can quickly contaminate the quality of the forced air.

2.14 Lightning.

When personnel are subjected to direct lightning strikes, the results are nearly always fatal.

Although extraordinary escapes from direct strikes have been reported, the shock is usually so great that survival is rare. The major portion of lightning casualties arises from secondary effects, such as side flashes and induced charges.

Note: If administered in time, first-aid treatment, especially artificial respiration or cardio-pulmonary resuscitation may prevent death.

Assess your lightning risk and take appropriate actions. During thunderstorms, no place outside is safe. If you can hear thunder, lightning is close enough to strike. Stop what you are doing and seek safety in a substantial building or a hard-topped metal vehicle.

Lightning: What You Need to Know

• NO PLACE outside is safe when thunderstorms are in the area!!

• If you hear thunder, lightning is close enough to strike you.

• When you hear thunder, immediately move to safe shelter: a substantial building with electricity or plumbing or an enclosed, metal-topped vehicle with windows up.

Stay in safe shelter at least 30 minutes after you hear the last sound of thunder.

For additional information about lightning safety see: www.lightningsafety.noaa.gov/tips.htm http://www.lightningsafety.noaa.gov/tips.htm

2.15 Toxic Agents.

Toxic agents are poisonous substances that can cause injury by contact or injection. Substances termed “caustic” or “corrosive” cause the flesh to be dissolved on contact; the results of contact with these agents range from minor skin irritations to severe burns. There are materials that are toxic only if they are taken internally. Toxic agents also exist as a gaseous vapor and may be injurious immediately or over a long period of time. There are also a few substances used in electric equipment that are basically non-toxic agents, but under certain conditions can become highly toxic.

2.15.1 Carbon Tetrachloride.

Never use carbon tetrachloride. Contact with liquid carbon tetrachloride destroys the natural oils of the skin, producing a whitish appearance on skin surfaces that are exposed. Continuous skin exposure may cause skin eruptions. Carbon tetrachloride fumes are highly toxic.

2.15.2 Trichloroethylene.

This agent, used principally as a degreasing solvent, is a narcotic and anesthetic material.

Organic injury rarely results from overexposure, but repeated overexposure can cause anemia and liver damage.

2.15.3 Battery Acids.

The most common battery acid is sulfuric acid. Sulfuric acid is a corrosive toxic agent; repeated or prolonged inhalation of its fumes can cause inflammation of the upper respiratory tract, leading to chronic bronchitis. Loss of consciousness with severe damage to the lungs may result from inhalation of concentrated vapors when the sulfuric acid is hot. Sulfuric acid, when used in a highly concentrated form (prior to adding water for battery use), acts as a powerful caustic, destroying skin and other tissue on contact. This destruction appears as severe burns, and such exposure may be accompanied by shock and collapse. The fumes from highly concentrated sulfuric acid cause coughing and irritation of the eyes; prolonged exposure may produce chemical pneumonitis.

Batteries and battery acid also produce hydrogen gas, a by-product of the charging process.

Hydrogen gas, when mixed with air in the right proportions, is highly flammable and can react explosively in conjunction with a spark or flame.

All locations where lead-acid batteries are used or housed should have, as a minimum, an emergency eyewash station installed. If water is not readily available, portable emergency eyewash stations consisting of a wall mountable water bottle should be made readily available.

2.16 Fire Extinguishers.

Conveniently locate fire extinguishers of the proper type (see paragraph 2.15.4), and in good working condition, near all high-voltage equipment. For additional details about fire extinguishers, see NFPA 10, Standard for Portable fire Extinguishers.

2.16.1 A Brief Introduction to Fire Extinguishers and Fire Types.

When used properly, portable fire extinguishers can save lives and property by extinguishing or containing a small fire until the fire department arrives.

Portable fire extinguishers, however, are not designed to fight large or spreading fires. Even for small fires, they are useful only under certain conditions:

• The operator must know how to use the extinguisher. There is no time to read directions during an emergency.

• The extinguisher must be within easy reach and in working order, fully charged.

• The operator must have a clear escape route that will not be blocked by fire.

• The extinguisher must match the type of fire being fought. Extinguishers that contain water are unsuitable for use on grease and electrical fires.

• The extinguisher must be large enough to put out the fire. Many portable extinguishers discharge completely in as few as 8 to 10 seconds.

2.16.2 How to Use Portable Fire Extinguishers.

Remember the PASS system:

P…Pull the Pin A…Aim the extinguisher nozzle at the base of the flames S…Squeeze trigger while holding the extinguisher upright S…Sweep the extinguisher from side to side

ALWAYS make sure the fire department is called and inspects the fire site, even if you think you have extinguished the fire!

2.16.3 Should You Try to Fight the Fire?

Before you begin to fight a fire:

• Make sure everyone has left or is leaving the building

• Make sure the fire department is called

• Make sure the fire is confined to a small area and is not spreading

• Make sure you have an unobstructed escape route to which the fire will not spread

• Make sure you have read the instructions and know how to use the extinguisher.

It is reckless to fight a fire in any other circumstances. Instead, leave immediately and close off the area.

2.16.4 Class of Fire Extinguishers.

Fire extinguishers are divided into four categories that are based upon different types of fires.

Each fire extinguisher also has a numerical rating that serves as a guide for the amount of fire the extinguisher can handle; the higher the number, the more fire-fighting power. The following is a quick guide to help choose the right type of extinguisher:

• Class A extinguishers are for combustible materials such as paper, wood, cardboard, and most plastics. The numerical rating on these types of extinguishers indicates the amount of water it holds and the amount of fire it can extinguish.

• Class B fires involve flammable or combustible liquids such as gasoline, kerosene, grease and oil. The numerical rating for Class B extinguishers indicates the approximate number of square feet of fire it can extinguish.

• Class C fires involve electrical equipment, such as appliances, wiring, circuit breakers and outlets. Never use water to extinguish Class C fires – the risk of electrical shock is far too great! Class C extinguishers do not have a numerical rating. The C classification means the extinguishing agent is non-conductive.

• Class D fire extinguishers are commonly found in a chemical laboratory. They are for fires that involve combustible metals, such as magnesium, titanium, potassium and sodium. These types of extinguishers also have no numerical rating, nor are they given a multi-purpose rating – they are designed to Class D fires only.

Some fires may involve a combination of these classifications.

2.16.5 Most Common Types of Fire Extinguishers.

a. Water extinguishers or air-pressurized water (APW) extinguishers are suitable for Class A fires only. Never use a water extinguisher on grease fires, electrical fires or Class D fires – the flames will spread and make the fire bigger! Water extinguishers are filled with water and pressurized with oxygen. Again – water extinguishers can be very dangerous in the wrong type of situation. Fight the fire only if you are certain it contains ordinary combustible materials.

b. Dry chemical extinguishers come in a variety of types and are suitable for a combination of Class A, B and C fires. These are filled with foam or powder and pressurized with nitrogen.

(1) BC - This is the regular type of dry chemical extinguisher. It is filled with sodium bicarbonate or potassium bicarbonate. The BC variety leaves a mildly corrosive residue which must be cleaned immediately to prevent any damage to materials.

(2) ABC – This is the multipurpose dry chemical extinguisher. The ABC type is filled with monoammonium phosphate, a yellow powder that leaves a sticky residue that may be damaging to electrical appliances such as a computer.

Dry chemical extinguishers have an advantage over CO2 extinguishers because they leave a non-flammable substance on the extinguished material, reducing the likelihood of re-ignition.

Carbon Dioxide (CO2) extinguishers are used for Class B and C fires. CO2 extinguishers contain carbon dioxide, a non-flammable gas, and are highly pressurized. The pressure is so great that it is not uncommon for bits of dry ice to shoot out the nozzle. They don’t work very well on Class A fires because they may not be able to displace enough oxygen to put the fire out, causing it to re-ignite.

CO2 extinguishers have an advantage over dry chemical extinguishers because they don’t leave a harmful residue – a good choice for an electrical fire on a computer or other electronic device.

It is vital to know what type of extinguisher you are using. Using the wrong type of extinguisher for the wrong type of fire can be life-threatening.

2.17 First Aid.

First aid is performed before the doctor arrives - it is never a substitute for qualified medical help. The maintenance technician should perform the lifesaving measures necessary in emergencies, but avoid doing any harm. Many first-aid measures are quite simple and do not require “split-second speed” in their application. Haste without knowing what one is doing can be worse than doing nothing at all. At other times, immediate action is essential to save a life or prevent serious complications; this action can only be taken by someone who is on the scene when minutes are vital. Learn about first aid before emergencies happen. Be prepared to give help safely and beneficially when necessary. Contact the American Red Cross to provide refresher first-aid courses to maintenance personnel to keep them proficient.

Chapter 3. Maintenance Management.

3.0 Maintenance Philosophy.

The purpose of the maintenance management system is to ensure the maximum availability of any given system at a minimum cost in man-hours or funds. “Availability” and “costs” are relative terms; they must be interpreted for each airport.