Electronics Material Officer Course

MODULE NUMBER TWO

LESSON TOPIC ONE

ELECTRONICS SAFETY

LESSON TOPIC OVERVIEW

LESSON TOPIC ONE

ELECTRONICS SAFETY

This lesson topic presents information about duties and organizational relationships, the electronics division organizational manual and EMO relieving procedures.

The LEARNING OBJECTIVES of this LESSON TOPIC are as follows:

The student should review the "LIST OF STUDY RESOURCES" and read the Lesson Topic LEARNING OBJECTIVES before beginning the lesson topic.

LIST OF STUDY RESOURCES

ELECTRONICS SAFETY

To learn the material in this LESSON TOPIC, you will use the following study resources:

Written Lesson Topic presentations in the Module Booklet:

Additional Materials:

References:

LESSON TOPIC SUMMARY

ELECTRONICS SAFETY

Lesson Topic One introduces you to safety as it pertains to the EMO and Electronics Safety Officer. You will learn what the safety organization is, what your responsibilities are, and what to look for in your spaces. The lesson narrative is organized as follows:

NARRATIVE FORM

OF

ELECTRONICS SAFETY

LESSON TOPIC 2.1

The goal of the safety program is to prevent accidental injury or death, and prevent damage to equipment. Type commander requirements and command responsibilities are identified in the following paragraphs.

TYCOM requires that commands:

Commanding Officer

The Commanding Officer is ultimately responsible for safety. The Commanding Officer must ensure that personnel know and comply with all safety precautions and procedures. Authority is delegated to subordinates for the execution of details.

The Safety Officer must ensure that the command's safety organization accomplishes the following:

Personnel and equipment safety is a major responsibility of the EMO. Because of the inherent dangers of working on electronic equipment, safety precautions are an important part of the electronics training program. The EMO's responsibilities concerning safety generally include the areas of training, promotion, and enforcement. Specifically, the EMO's safety responsibilities are:

The division safety petty officer's responsibilities are:

Supervisors must set good personal examples and ensure that safety precautions are strictly followed. All personnel must strictly observe safety precautions. Accident prevention is everyone's business. All personnel must:

Post-accident investigations have revealed that the majority of accidents are caused by unsafe practices. Most of these practices are known beforehand to be unsafe and in violation of safety regulations. Other factors include fatigue, monotony, preoccupation at a critical moment (inattentiveness), mental and/or physical problems, improper supervision, and lack of motivation. All personnel, even "old salts", need to be reminded to work safely. Reports of senior electrical and electronics personnel involved in fatal accidents illustrate this point. People do not always act (or react) as they were trained or directed. Humans make mistakes. By their action or inaction they cause, or fail to prevent, accidents. In order to prevent accidents personnel must always be mentally and physically alert to potential hazards. Training, reminders, and good personal examples will create a climate of safety awareness. Use the electrical safety program checklist, Appendix B7-A in OPNAVINST 5100.19, to spot check your division's safety compliance. Your safety petty officer can help by conducting periodic safety inspections.

Type commanders require that the Electronics Doctrine contain a section on safety. This provides a ready reference to train personnel on general and ship-specific safety precautions. Safety Precautions for Forces Afloat requires that all personnel, when reporting aboard and annually thereafter, receive indoctrination on basic electrical safety. Annual electrical safety training must include the following topics:

Additionally, the following points should be emphasized:

OPNAVINST 5100.19 also requires that all electrical/electronics associated ratings receive annual Cardio-Pulmonary Resuscitation (CPR) training from an certified instructor. The recent extension of CPR qualification to two years does not change the annual requirement for electrical/electronic ratings. Track the CPR qualifications of your personnel to ensure annual requalification. It is easier to keep personnel certified if one of your technicians qualifies as a CPR instructor.

In addition to indoctrination and annual training, remember to schedule regular divisional training on electrical/electronic safety. To emphasize safety daily you can submit safety notes for the POD, post safety posters, and distribute safety publications (periodicals and pamphlets). Electrical safety posters are listed in EIMB General and NAVSUP 2002. If you use posters change or rotate them regularly to draw attention to them. A variety of warning signs are also required. You will find these listed in the EIMB, NSTM Chapter 300, and RADHAZ publications. Additionally, when a mishap occurs, conduct training to prevent future occurrences.

Written safety precautions should include information concerning electric shock. Ensure the following general warnings are stressed:

Factors determining the extent of body damage resulting from electric shock are:

Generally, the greater the current or the longer the current flows, the greater the body damage.

Body damage is more likely to occur when the current flow is through or near nerve centers and

vital organs. An alternating current at a frequency of 60 Hz is considered slightly more dangerous than an AC at a lower frequency, or than direct current (DC). This is because ventricular fibrillation is produced with just 60 to 100 mA of 110 to 220 volts AC at 60 Hz, while 300 to 500 mA of DC voltage is required for the same reaction. However, the same precautions that apply to 60 Hz AC also apply to DC. Humans differ in their resistance to electric shock. A current flow that may cause only a painful shock to one person can be fatal to another. Table 2-1.1 shows the effects of 60 Hz current flowing through the body. Tests show that the resistance of the human body may be as low as 300 ohms under unfavorable conditions such as those caused by salt water and perspiration. Therefore, it is possible for a voltage potential as low as thirty volts to cause a fatal 100 mA current flow through the body.

Table 2-1.1 Effects of 60 Hz Current

Safety requirements concerning various shop and work areas aboard ship are prescribed by the Safety Precautions for Forces Afloat, OPNAVINST 5100.19; Naval Ships' Technical Manual, Chapters 300, 313, 400, and 634; and the EIMB, General, NAVSEA SE000-00-EIM-100. You must ensure that the following general safety precautions are complied with:

The best way to avoid electrical hazards is to completely deenergize circuits on which work must be done. As a division officer, you will sign Tag Guide Lists (TGL) that will be used to tagout equipment. The TGL identifies how to isolate power from the circuit. Circuits are deenergized by opening all power supply circuit breakers/switches or removing appropriate fuses through which power can be supplied. Tagout procedures were covered in SWOS Division Officer Course. You must ensure that these procedures are strictly complied with. Familiar yourself with SORM, type commander, and unit tagout instructions.

Technicians must minimize access to open equipment by posting signs, erecting barricades, or securing the covers of unattended equipment. The following precautions ensure that a circuit is deenergized:

Technicians who work on circuits that use large capacitors, pulse forming networks, etc. must use an authorized safety shorting probe to discharge the circuits. Shorting probes should be located in electrical/electronic equipment spaces (e.g., by switchboards, in CIC, and in radar rooms). Figure 2.1-1 shows the approved shorting probe with mounting assembly.

Figure 2.1-1 Shorting Probe and Holder Assembly

Because of possible misuse of the threads in the handhold section of the probe, NAVSEA has recommended that a #20 nylon screw be installed in the handhold end (EIB 932). Also, the head of this screw must be cut off after installation to prevent removal. Inspect shorting probes for the following:

When using the general purpose safety shorting probe, technicians must connect the grounding clip first. If necessary, they scrape the paint off the grounding metal to make good contact. Then, while holding the safety shorting probe by the handle behind the protective shield, the end of the metal rod is brought into contact with the point to be shorted. Each point should be shorted to ground several times to ensure that the circuit is completely discharged. Technicians must be extremely careful that they do not touch any of the metal parts of the safety shorting probe while touching the probe to a "hot" terminal. Some electronic equipment have built-in special purpose safety shorting probes. These probes are not general purpose, and are to be used only with the equipment with which they are provided, as directed by equipment technical manuals. Ensure that they are not removed and used elsewhere.

Energized electrical equipment shall not be disassembled nor undergo any maintenance without approval by the Commanding Officer. Exceptions to this policy are as follows:

In addition to the general precautions cited previously, the following precautions must be observed for circuits greater than or equal to thirty volts:

When work is particularly hazardous (e.g., involves switchboard interiors or other cubicles where exposed energized bus bars are in the vicinity of the work) or the work requires contact by tools to energized components, the following precautions must also be taken:

Figure 2.1-2 Worksite Danger Sign

The following rules must be observed for all inside work areas:

The following rules must be observed for all outside work areas:

Aloft is defined as any mast, stack, mack (combination mast/stack), or kingpost. In addition to personnel falling, other hazards associated with working aloft are falling objects, radiation burns, and asphyxiation from stack gases. To go aloft your technicians must obtain permission from the Officer of the Deck (OOD) using a Working Aloft Check Sheet (Appendix C8-B in OPNAVINST 5100.19C). When the ship is underway, the Commanding Officer's permission is required to go aloft. The OOD will ensure the following:

Also, all radio transmitters and radars that pose radiation hazards are placed in standby and a sign placed on the equipment that reads: "Secured. Personnel aloft. Date , Time , Initials ." See NAVSEA OP3565 Volume One for fixed and moving beam exposure distances and times. Additionally, on aviation capable ships your technicians must understand the importance of Foreign Object Damage (FOD) control. After completing work topside, all tools and materials must be removed, as they may cause damage to aircraft or injury to personnel. Metallic items left in these areas may also create electromagnetic interference (EMI).

Ensure that technicians working aloft follow these rules:

A climber safety rail will be installed at each permanently installed topside ladder on masts, kingposts, and other similar topside structures that provides access to a fall-hazard location at which a person is expected to wear a safety harness (General Specifications for Navy Ships, Section 622). Climber safety rails are installed in accordance with NAVSHIPS Drawing 80064-804-4563125, Rev. C, and bonded in accordance with MIL-STD-1310. Where safety rails are installed and where a climber must transfer from one ladder to another, or from a ladder to a platform, padeyes will be provided to enable the climber to make a transfer, while tethered at all times to either a padeye or climber safety rail. NAVSHIPS drawing 80064-804-4563125 Rev C, states that all climber safety rails must be made of CRES steel. Obtain parts availability information from FTSC, RSG, SIMA, or NAVSAFCEN. Where rigid-rail type installation is not practical (i.e., for ladders less than twelve inches wide or peg-rung ladders on pole masts), a retractable-wire type installation is used. The fall prevention device is available through the national stock system. It must be bonded in accordance with MIL-STD-1310.

A potential electrical shock hazard may exist in equipment powered from multiple sources, even when the main power is turned off. Multiple sources include primary/alternate power connections and synchro or gyro inputs. Multiple source equipment should have a warning label (Figure 2.1-7) attached that lists all incoming power circuits, identification of the power disconnect switch, and power disconnect switch location. Technicians must complete and attach labels in a conspicuous location on equipment. Drawings, manuals, instruction books, etc., should be used to ensure that the information is accurate. The label can be marked with pencil or felt tip pen however, a ball point pen or type is more durable.

Figure 2.1-7 Multiple Source Warning Label

Electronic equipment connected directly to the ship's electrical power distribution system must have switches to disconnect the equipment from all power sources. These switches must be located in the space where the equipment is located. When practical, electronic equipment distribution panels or boxes with switches will be used. Single disconnect switches should be located as close as practical to the equipment they serve. All remote equipment of an electronic system will have safety disconnect switches that allow independent power disconnect.

Electronic equipment with inputs of thirty volts (RMS¹) or greater and that cannot be disabled by the system main power switch, will have disconnect switches or protective devices and warning signs. Radar indicators are included in this requirement. The disconnect switch for a radar indicator will be installed as close as practical to its associated indicator.

Hemostats

and appropriate

bags

The greatest danger from wet cell (lead acid) batteries is hydrogen gas produced during the charging of the battery. All flames and sparks or flame/spark producing items must be kept away from wet cell batteries. Eye and skin protection must be worn. An eyewash station must be located in the space. Lead-acid and alkaline batteries (nickel-cadmium, silver-zinc, nickel-iron, silver-cadmium, nickel-zinc), lithium, and dry cell batteries (Lelanche, mercury, and low-temperature cells) must be containerized for shore disposal. Check with your safety officer regarding disposal at sea. Ensure that personnel do not empty electrolyte from batteries. Personnel should never pierce, crush, burn, dismantle, or alter batteries. Corneal burns or blindness can occur with exposure to acidic battery electrolytes when batteries vent.

Mercury batteries can explode if misused. The following safety precautions must be taken:

Lithium batteries are potentially hazardous. Use of lithium batteries is only allowed when no other safer, environmentally approved battery will do the job. Lithium battery approval extends to a specific application and no other. Lithium batteries must not be tampered with before, during, or after discharge. Lithium batteries can cause fires and even explode while rapidly discharging and up to thirty minutes after a rapid discharge. The type of accident most likely to occur, however, is the battery venting toxic gases, such as sulfur dioxide gas. Sulfur dioxide gas causes severe irritation to eyes and mucous membranes. The sulfur dioxide forms sulfurous acid when it comes in contact with moist membranes, can cause fluid build-up in the lungs, and can cause a person to stop breathing. Corneal burns or blindness can occur with exposure to liquid sulfur doxide. Whatever the state of charge, technicians must never pierce, crush, burn, intentionally drop, dismantle, modify, or carelessly handle lithium batteries. Lithium batteries must not be short circuited, charged, or used in any equipment other than the equipment specified for the battery.

Most transformers, capacitors, and similar components contain coolants, usually in the form of oils. Some of these coolants contain polychlorinated biphenyls or PCBs. PCBs are toxic to people and the environment. Restrictions have been placed on their manufacture and use. The U.S. Navy implemented a program in 1981 to control the use of PCBs. PCBs are very stable chemicals with many favorable characteristics, including high heat capacity, non-corrosivity, low flammability, and low electrical conductivity. However, PCBs cause adverse health effects, including irritation to the skin, eyes, and lungs, during even relatively brief exposures. PCBs ingested by people or animals are stored in fat tissues and can cause metabolic defects and tumors. PCBs can be absorbed through the skin and, at higher temperatures, vaporize into a toxic air contaminate. Ensure that technicians are trained in the potential hazards of PCBs. NAVSEA has distributed a list of components that contain or are suspected to contain PCBs. These items must be labeled, and a contingency plan developed in case of a leak or spill. Detailed information on PCBs is provided in the Shipboard Management Guide for Polychlorinated Biphenyls (NAVSEA S9593-A1-MAN-010).

Technicians who smoke while using volatile cleaning solvents are inviting disaster. The navy does not permit the use of gasoline, benzene, ether, or similar solvents for cleaning purposes because they present potential fire or explosive hazards. Only non-volatile solvents will be used to clean electrical or electronic equipment. Most cleaning solvents can also damage the human respiratory system. Technicians must observe the following precautions:

If using water compounds is not possible, inhibited methyl chloroform (also known as 1, 1, 1 and Trichloroethane) should be used instead of carbon tetrachloride. Methyl chloroform is a halogenated hydrocarbon extensively used as a solvent. It is an effective cleaner and safe when used with adequate ventilation and observing fire precautions. Direct inhalation of inhibited methyl chloroform vapors must be avoided. When properly used its vapors have a low order of toxicity. However, vapors of this solvent, especially when sprayed or heated, will readily accumulate in confined spaces and increase the chance of harmful exposure. Liquid cleaners are toxic if taken internally and when heated separate into subproducts which may be more toxic. For additional information refer to EIMB General, Safety Precautions for Forces Afloat, Hazardous Materials Information System (HMIS), and NSTM Chapters 100 and 670.

General Specifications for Navy Ships, Section 665, states that the only authorized workbench for repair of electrical/electronic equipment in electrical/electronic work spaces is the one shown in NAVAIR Drawing 63-A-114J. This workbench is illustrated in Figure 2.1-4. The top and front of electrical/electronic workbenches, kneeholes, and all other exposed metal areas must be insulated with 1/8-inch approved high pressure laminate. The brand name of this material is BENELUX or ARBORON. Handles must not be made of metal. The deck surrounding the workbench must be

insulated with electrical grade matting. To further reduce the chance of electric shock:

Figure 2.1-4 Authorized Electrical/Electronic Workbench

NSTM Chapter 300 states that "Personally-owned equipment/appliances such as portable radios, electric shavers, curling irons, hair dryers, hobby equipment, etc. are not of standard issue. Personal equipment can be approved for shipboard use when adequate government-owned equipment is not available to meet the need and the equipment has been inspected by the electrical/electronics shop and passes inspection for safe, rugged construction and test requirements of paragraph 300-2.7.5.1. Any personal equipment which fails to pass this inspection and testing must be appropriately modified to meet these requirements or its use shall be forbidden aboard ship. Final acceptance or rejection is at the discretion of the officer in charge of the inspecting shop. Additionally, electronic equipment that is not double-insulated or that does not have a case and handle made of non-conducting material and does not pass a inspection for rugged, safe construction and have a minimum of 1W DC resistance from any phase conductor to any exposed metal, part, or metal chassis must have a built-in power transformer that completely isolates the primary or line side of the transformer from the secondary or equipment side.

│ │

│ │

│ Date │

│ │

│ From: (Name, Rank/Rate) │

│ To: Division Officer │

│ Via: Electrical Officer/Electronics Material Officer │

│ │

│ Subj: PERSONAL ELECTRIC/ELECTRONIC EQUIPMENT REQUEST │

│ │

│ 1. I request permission to have on board the following personal │

│ electrical/electronic equipment. If approved, I understand I am to │

│ keep it in good physical condition and have it reinspected every six │

│ months and when damaged or altered. │

│ │

│ Equipment Model │

│ │

│ Make Serial No. │

│ │

│ │

│ │

│ │

│ Signature │

│ │

│ ......................................................................... │

│ │

│ │

│ Date │

│ │

│ First Endorsement │

│ │

│ From: Electrical Officer/Electronics Material Officer │

│ To: Division Officer │

│ │

│ 1. The equipment listed above has been inspected and meets the │

│ minimum safety requirements for shipboard use. The equipment │

│ has been tagged and entered in the ship's personal electrical/ │

│ electronic equipment data base. │

│ │

│ │

│ │

│ Electrical Officer/ │

│ Electronics Material Officer │

│ │

│ ......................................................................... │

│ │

│ │

│ Date │

│ │

│ Second Endorsement │

│ │

│ From: Division Officer │

│ To: (Name, Rank/Rate) │

│ │

│ 1. The equipment listed above is authorized for use on board. It │

│ must be turned in for inspection every six months or when altered or │

│ damaged. Failure to comply could result in the removal of the │

│ equipment from the ship. │

│ │

│ Division Officer │

┌────────────────────────────────────────────────────────────┐

│ EQUIPMENT TYPE │

├──────────────┬────────────────────┬────────────────────────┤

│TEST │PERSONAL │SHIP'S │

┌────────────────┼──────────────┼────────────────────┼────────────────────────┤

│APPLICABLE │S-1R │N/A │A-6, A-7, M-2, M-4 │

│MRC │ │ │ │

├────────────────┼──────────────┼────────────────────┼────────────────────────┤

│PERIODICITY │4-8 MONTHS │NOT TO EXCEED │A-6/A-7: 3-5 QUARTERS │

│ │ │SIX MONTHS │M-2/M-4: 3-6 WEEKS │

├────────────────┼──────────────┴────────────────────┴────────────────────────┤

│DATE │NOTE DATE CHECKED ON TAG, TAPE OR STICKER TO AVOID CONFUSION│

│ │AS, E.G., 17SEP95. IF ONLY MONTH/YEAR HAS BEEN NOTED, USE │

│ │1ST DAY OF MONTH NOTED TO DETERMINE DATE DUE. │

├────────────────┼────────────────────────────────────────────────────────────┤

│LOCATION OF TAG │TAG MAY BE HUNG ANYWHERE ALONG CORD. │

├────────────────┼──────────────┬────────────────────┬────────────────────────┤

│RECOMMENDED TAG │MRC#, DATE │EQP SERIAL#, │MRC#, DATE CHECKED, │

│INFORMATION │CHECKED, │DATE CHECKED, │INITIALS OF CHECKER, │

│ │INITIALS OF │INITIALS OF │PERIODICITY, WORK │

│ │CHECKER, │CHECKER, │CENTER CONDUCTING │

│ │PERIODICITY, │PERIODICITY, │PMS │

│ │WORK CENTER │WORK CENTER │ │

│ │CONDUCTING │CONDUCTING │ │

│ │PMS │SAFETY CHECK │ │

├────────────────┼──────────────┼────────────────────┼────────────────────────┤

│ STICKER │NONE │RECOMMEND USING │NONE │

│ │ │STICKER ON EQP │ │

│ │ │WITH DETACHABLE │ │

│ │ │CORD. STICKER │ │

│ │ │SHOULD INDICATE │ │

│ │ │SAME INFORMATION │ │

│ │ │AS TAG OR INDICATE │ │

│ │ │"AUTHORIZED FOR USE │ │

│ │ │WITH BATTERIES ONLY"│ │

├────────────────┼──────────────┴────────────────────┴────────────────────────┤

│MATERIAL │EVEN THOUGH EQUIPMENT MAY HAVE A CURRENT SAFETY TAG, │

│CONDITION │DAMAGE TO THE CORD, PLUG OR CASING INVALIDATES THE │

│ │SAFETY TAG. CHECK FOR SPLICES, EXPOSED CONDUCTORS │

│ │CUTS, TEARS, ABRASIONS, BROKEN EQUIPMENT CASINGS THAT │

│ │EXPOSE INTERNAL COMPONENTS AND POWER CORD MODIFICATIONS. │

└────────────────┴────────────────────────────────────────────────────────────┘

Figure 2.1-8 Personnel RFR Exposure Chart

Any ordnance containing EEDs, which has not been classified as HERO safe or susceptible by either test or design analysis is classified as HERO unsafe ordnance.