Electrical Safety Quick Links
Electrical Safety Program Summary
The Electrical Safety program provides information regarding installation requirements and safe work practices for individuals working on live electrical systems or equipment energized at 50 volts or more.
This program applies to personnel who face a risk of electrical shock or related injuries from work on energized electrical systems of 50 volts (ac or dc) or more. Personnel working on or near energized electrical systems must be "qualified." This program sets forth the policy for working on energized systems and the process by which personnel become "qualified." This program relies heavily on the 2021 edition of the National Fire Protection Association's 70E, "Handbook for Electrical Safety in the Workplace."
Note: Electrical research operations must be supervised by a "qualified person," and where personnel may be exposed to shock or arc-flash events, additional training is required. The design and use of electrical research systems must comply with the requirements of this program. For more information on Electrical Safety for Research.
- New electrical wiring, the modification, extension, or replacement of existing wiring must conform to the requirements of the National Electric Code (NEC), the Virginia Uniform Statewide Building Code, and Occupational Safety and Health (OSHA). Requirements and oversight are provided by the Office of the University Building Official.
- All personnel who face a risk of electrical shock, burns, or related injuries must be trained in electrical safe work practices and be "qualified."
Electrical Safety Online Program
Environmental Health and Safety developed the Electrical Safety Program to reduce exposures related to energized electrical work and to assure the safety of personnel who face a risk of electrical shock, arc flash events, or related injuries as part of their job duties. The program complies with the requirements and intent of the OSHA regulations and relies heavily on industry standards, such as the National Fire Protection Association’s (NFPA) 70E-2021 “Electrical Safety in the Workplace.” The Electrical Safety Program also assures that all departments that perform electrical work on campus follow uniform work practices.
Each department that performs work covered by this program must designate one or more employee(s) to coordinate the requirements of this program at departmental worksites. Program coordinators will assist Environmental Health and Safety with training departmental staff that work on or near electrical systems and will review and verify the skills and competency of departmental workers.
All construction, renovation, and maintenance of university facilities must be in accordance with University Policy 5405 to ensure full compliance of the design and execution of the work with applicable codes, standards, permitting requirements, and other university concerns.
This program provides a system for ensuring that personnel performing energized electrical work, including voltage testing and diagnostics, are trained in the safety aspects of such work and have been qualified by their supervisor to perform the task assigned. The training offered by Environmental Health and Safety associated with this program covers personal safety issues regarding work on electrical systems and includes relative information to be gathered while analyzing electrical-related hazards, which safe work practices may apply, and selection, use and care of appropriate electrical-related personal protective equipment.
Qualified persons are those who have received specific training and have demonstrated the skills necessary to work safely on or near exposed energized parts. An individual may be qualified to work, for example, on circuits up to 600 volts, but may be unqualified to work on higher voltages. Only qualified persons may place or remove locks and tags on energized electrical systems.
Note: A individual undergoing on-the-job training who has demonstrated the ability to perform duties safely at his or her level of training, and who is under the direct supervision of a qualified person, is considered to be a qualified person for the purpose of those duties.
Unqualified persons are those with little or no such training.
This program applies to work performed by persons working on or near:
- Premises wiring: Installations of electric conductors and equipment in or on buildings or other structures, and in other areas such as yards, parking and other lots, and industrial substations.
- Wiring for connection to supply: Installations of conductors that connect to the supply of electricity.
- Other wiring: Installation of other outside conductors on the premises.
- Optical fiber cable: Installation of optical fiber cable near or with electric wiring.
Safe work practices also apply to work performed by unqualified persons near energized electrical conductors, equipment, or systems.
Students performing work on energized systems in research applications must be supervised by a qualified person, and must be trained on the hazards of electricity and the methods used to control or eliminate those hazards. For more information on Electrical Safety for Research.
Environmental Health & Safety responsibilities for this program include:
- Developing, implementing, and administering the program.
- Training on the program requirements and maintaining centralized records.
- Serving as a technical resource for application of program requirements.
- Providing guidance on the selection of protective equipment.
- Evaluating the overall effectiveness of the program on a periodic basis and making appropriate changes as needed to assure the safety of personnel.
Involvement by Environmental Health & Safety does not relieve the departments, supervisors, or contractors of their individual responsibilities.
Departments are expected to maintain safe and healthy living, learning, and working environments for faculty, staff, students, and visitors to our campus.
- Each department performing energized electrical work must ensure that personnel assigned to such work are qualified, trained, provided with appropriate protective equipment, and are following approved procedures.
- Departments must ensure that all employees performing electrical work have attended Environmental Health and Safety Electrical Qualified Person training, Lockout/Tagout Authorized Person training, and are currently certified in first aid/CPR/AED.
- Departments involved in electrical research must ensure that all projects are designed in compliance with accepted safety criteria and code intent. To facilitate compliance with these requirements, it is recommended that the department assign the duties outlined in this program to either a safety committee composed of qualified faculty and staff, the principal investigator, and/or the program supervisor as appropriate for the scope of departmental operations and conditions of use. The principal investigator and/or the program supervisor are responsible for assuring the acceptability of experimental electrical wiring and apparatus.
- Departments must ensure that electrical systems and related equipment are maintained in a safe manner in order to protect employees, students, and the public from hazardous conditions. Unsafe electrical conditions should be reported to the Division of Campus Planning, Infrastructure, and Facilities immediately for correction at 540-231-4300.
Employees who perform energized electrical work on systems greater than 50 volts (ac or dc) must:
- Follow the requirements of this program.
- Attend required training.
- Wear assigned personal protective equipment.
- Know and respect the limitations of his or her technical skills and knowledge.
Contractors must comply with all local, state, and federal safety requirements, and must assure that all employees performing work on Virginia Tech property have been suitably trained and are provided appropriate personal protective equipment per the Safety Requirements for Contractors and Subcontractors program.
All non-capital construction, renovation, and maintenance of university-owned facilities, and the installation of equipment within those facilities, shall be accomplished under the management and direction of the Division of Campus Planning, Infrastructure, and Facilities, per Policy 5405. Contractors performing electrical work on university property must coordinate such work with their project manager to assure both parties are informed of existing hazards, personal protective equipment requirements, related safe work practices, and related emergency procedures. This meeting should be documented by Virginia Tech personnel.
An “unqualified person” is any person who has not received specific training regarding electrical hazards involved in the work task and how to avoid the hazards. Environmental Health & Safety offers awareness level training to unqualified persons who would like more information regarding common electrical hazards and protective measures, including safe work practices for extension cords and ground-fault circuit-interrupters (GFCI).
An unqualified person may assist a qualified person provided that they are wearing appropriate personal protective equipment for the approach boundary they are crossing (i.e. either Limited Approach Boundary or Arc Flash Boundary), and are escorted by the qualified person at all times. Under no circumstances must the unqualified person cross the Restricted Approach Boundary.
Qualified persons must be designated (i.e. authorized) by their department to perform work on energized electrical systems or equipment and must attend relative required Environmental Health & Safety training. Environmental Health & Safety training is intended to work in conjunction with any on-the-job technical training that the department provides or requires.
Note: Environmental Health & Safety Electrical Qualified Person training provides information related to live electrical work hazards and selection and use of appropriate personal protective equipment. It is not intended to provide the technical skills and knowledge necessary to work on electrical systems or components, nor does it authorize any person to do so.
A person can be considered qualified with respect to certain equipment and methods, but unqualified for others.
Note: Unqualified persons assisting in energized electrical work must be under the direct supervision of a qualified person for the duration of the exposure once they cross the Limited Approach Boundary or the Arc Flash Protection Boundary. An employee who is undergoing on-the-job training and who, in the course of such training, has demonstrated an ability to perform duties safely at his or her level of training, and who is under the direct supervision of a qualified person shall be considered to be a qualified person for the performance of those duties.
Qualified persons must:
- Be trained and knowledgeable of the construction and operation of equipment or a specific work method, and be trained to recognize and avoid the electrical hazards that might be present with respect to that equipment or work method.
- Be familiar with the proper use of the special precautionary techniques, personal protective equipment, including arc-flash, insulating and shielding materials, and insulating tools and test equipment.
- Be trained in the skills and techniques necessary to distinguish exposed energized parts from other (non-energized) parts of electrical equipment.
- Be training in skills and techniques necessary to determine the nominal voltage of exposed live parts by reading drawings, signs, and labels.
- Be trained in the approach distances and the corresponding voltages to which the qualified person will be exposed.
- Be trained in the decision-making process necessary to determine the degree and extent of the hazard and the personal protective equipment and job planning necessary to perform the task safely.
- Attend Lockout/Tagout Authorized Person training.
- Be certified in first aid and CPR.
- Be familiar with emergency procedures for electrical incidents.
- Attend Confined Space Entry Training, if applicable.
Departments must establish and maintain documentation that provides evidence of the qualification of each employee, and the documentation must define the limits of each employee’s qualifications. The Electrical Qualified Person Form can be used for such purposes.
Design and Installation Requirements
Electrical equipment, including electrical apparatus for research and development, must be free from recognized hazards that are likely to cause death or serious physical harm. Equipment must be suitable for the installation and use and must be installed and maintained in accordance with the manufacturer’s instructions. Overloaded circuits, damaged wiring, and defective switches/outlets pose a potential fire hazard. Report any damage or defects to the Division of Campus Planning, Infrastructure, and Facilities at 540-231-4300 for repair or replacement.
The National Electric Code (NEC) is an installation code that provides adequate protection for people who use equipment or facilities. Any installed electrical service or equipment that meets the requirements identified in the NEC will be safe while the equipment is operating normally, provided that it is adequately maintained. Electrical installations must be in accordance with Virginia Tech's Office of the University Building Official.
If the equipment is not listed or labeled by a Nationally Recognized Testing Laboratory (NRTL), such as a custom-built research apparatus or equipment purchased from other countries, review, and approval must be completed.
Work performed on-premise wiring or wiring for connection to supply must meet current National Electric Code requirements regardless of who performs the work. Implementation, including interpretation, inspection, and enforcement of these code requirements is coordinated through the Office of the University Building Official. Responsibility and costs associated with remediation may fall to the department creating the non-compliant condition.
Sufficient access and working space must be provided and maintained around all electric equipment to permit ready and safe operation and maintenance of the equipment. Working clearances may not be less than 30 inches in front of electric equipment. Except as permitted by OSHA or the NEC, the working space in front of live parts operating at 600 volts or less that require servicing, inspection, or maintenance while energized may not be less than indicated in Table 3. This working space may not be used for storage.
Each disconnecting means (the switch or device used to disconnect the circuit from the power source) must be clearly labeling to indicate the circuit's function unless it is located and arranged so that the purpose is evident. Identification must be specific. All labels and markings must be durable enough to withstand the environment to which they may be exposed. Tape or labels directly attached to breaker switches are not permitted.
OSHA requires that electrical equipment be marked with descriptive markings, including the equipment's voltage, current, wattage, or other ratings as necessary.
NFPA 70E promotes hazard recognition and appropriate personal protective equipment labeling in addition to minimum OSHA labeling for switchboards, panelboards, industrial control panels, meter socket enclosures, motor control centers (installed after 2002) that are in "other than dwelling occupancies", and any equipment likely to require examination, adjustment, servicing, or maintenance while energized. This marking is intended to warn qualified persons of potential electric arc flashes before an examination, adjustment, servicing, or maintenance of the equipment. The labels should be located so as to be clearly visible prior to such work.
For equipment installed before 2002, the labeling must be applied if any modifications or upgrades take place. Such labeling is the result of a formal arc flash risk analysis and should be reviewed and updated at least every 5 years.
Live parts of electrical equipment operating at 50 volts alternating current (or 100 volts direct current) or more must be guarded against accidental contact by:
- Use of an approved cabinet or other approved enclosure (ex. cover plates, circuit breaker blanks);
- Location in a room or vault that is accessible to qualified persons only; or
- Elevating the equipment; or
- Controlling the arrangement of the space to prevent contact by unqualified persons.
If electrical equipment is located in an area where it is potentially exposed to physical damage or may fail as in the case of electrical research and development, the enclosure, location, or barrier must be sufficient enough to prevent such damage beyond the barrier.
Whenever possible, cord sets should be manufactured and listed by a nationally recognized testing laboratory. If job-made cord sets will be assembled by employees, the following requirements must be met.
Before starting each electrical job, the employee in charge shall conduct a job briefing with the employees involved – even where workers are skilled in the tasks. Reviewing related work task hazards and safety requirements is always beneficial. A job briefing is simply a discussion of the work task to be performed. It should be as extensive as necessary to ensure that workers have a complete understanding of their exposure to an electrical hazard prior to beginning the work task. The briefing must include a discussion of the following subjects:
- Electrical hazards (shock and arc flash) associated with the work task;
- Procedures that must be followed when executing the work task;
- Any special precautions that are required by the working conditions;
- Where and how to remove the energy source;
- Emergency response and emergency communications;
- Required personal protective equipment;
- Other work in the immediate physical area; and
- Other work associated with the same electrical circuits or equipment.
If the work to be performed during the workday or shift is repetitive and similar, at least one job briefing should be conducted before the start of the first job of the day or shift. If significant changes that might affect the safety of employees occur during the day, a new job briefing should be conducted.
If the work involved is routine and if the employee (by virtue of training and experience) can reasonably be expected to recognize and avoid the hazards involved in the job, a brief discussion shall be satisfactory. A more extensive discussion should be conducted if either of the following applies:
- The work is complicated or particularly hazardous.
- The employee cannot be expected to recognize and avoid the hazards involved in the job.
Job briefings must be documented where an Energized Electrical Work Assessment is required.
As part of the risk assessment process, approach boundaries should be determined. There are two shock protection boundaries; the Limited Approach Boundary (LAB) and the Restricted Approach Boundary (RAB), and one Arc Flash Boundary (AFB) that must be established in order to provide a safe distance for personnel from exposed, energized electrical components.
The Limited Approach Boundary (LAB) is the approach distance to exposed, energized electrical components within which a shock hazard exists. It is the approach limit for unqualified persons. Unqualified persons may only cross this boundary if they are under the direct supervision of a qualified person, and wearing the appropriate personal protective equipment for the hazards involved. Working within the LAB is only acceptable if an Energized Electrical Work Assessment has been completed and approved, or if the work is specifically exempt per NFPA 70E-2021 130.2(B)(3).
The LAB is determined by selecting the voltage range and exposed conductor/circuit condition (i.e. either movable or fixed, column 2 or 3) in NFPA 70E-2021 Table 130.4(E)(a) for alternating current. Use NFPA 70E-2021 Table 130.4(E)(b) for direct current.
The Restricted Approach Boundary (RAB) is the approach limit for qualified persons to exposed, energized electrical components where there is an increased likelihood of electric shock due to electrical arc-over combined with inadvertent movement. Only qualified persons may cross this boundary. A qualified person required to cross the RAB must be protected from unexpected contact with exposed energized conductors or circuit parts. Working within the RAB is only acceptable if an Energized Electrical Work Assessment has been completed and approved, or if the work is specifically exempt per NFPA 70E-2021 130.2(B)(3).
The RAB is determined by selecting the voltage range in NFPA 70E-2021 Table 130.4(E)(a) for alternating current (column 4). Use NFPA 70E-2021 Table 130.4(E)(b) for direct current.
The Arc Flash Boundary (AFB) is the distance from exposed, energized electrical components within which a person could receive a second degree burn if an electrical arc flash were to occur. The AFB is determined either through calculation or through the use of the following tables. Personnel must be wearing the appropriate arc-rated protective equipment before crossing this boundary. Arc-rating is reported as either the Arc Thermal Performance Value (ATPV) or the Energy of Break-open Threshold (EBT).
In order to determine if there is a likelihood of an arc flash occurrence, and whether protective equipment is required/recommended for a given task, identify the task in NFPA 70E-2021 Table 130.5(C). If there is a likelihood of an arc flash event occurring, NFPA 70E-2021 Table 130.7(C)(15)(a) for alternating current or table (b) for direct current can be used to determine the arc flash personal protective equipment category and the arc flash boundary based on the equipment involved. The category of personal protective equipment required is defined and detailed in NFPA 70E-2021 Table 130.7(C)(15)(c).
Note: Tables and charts referenced here are provided to personnel during Electrical Qualified Person training, or by contacting Environmental Health & Safety for more information.
If work falls outside of the parameters noted in the tables and charts referenced in NFPA 70E and the incident energy must be calculated, it must be performed by an electrical engineer and Environmental Health & Safety should be consulted for review.
To achieve an electrically safe work condition, the requirements of Virginia Tech’s Lockout/Tagout Program must be followed. Personnel performing electrical work must attend Lockout/Tagout Authorized Person training, which addresses hazardous energy sources, general lockout/tagout procedures, when specific written lockout/tagout procedures are required, and program guidelines.
Electrical systems and equipment in large facilities rarely stay the same for more than a few months or years. Electrical energy sources are sometimes difficult to identify, especially when the path of circuit conductors is not easily observed or historical work on the system has created questionable standards of practice or compliance.
Up-to-date drawings should be maintained on electrical systems and equipment and updated as necessary when changes are made. This is often a difficult task, but it is imperative to effectively communicate detailed information to personnel and contractors. Labels are another means of identifying and communicating information, but they must be complete and accurate as well. Inaccuracies identified should be reported to the Division of Campus Planning, Infrastructure, and Facilities immediately for correction.
Operating "adequately rated disconnecting means" is the next step in creating an electrically safe work condition. Energy-isolating devices establish a positive break in the conductors supplying energy. Simply operating an on/off control device is not sufficient to disconnect electrical equipment or circuits. The system must then be tested for the absence of voltage. For knife-style disconnects especially, the cover should be opened to visually inspect and verify that all phase conductors have opened. Poles sometimes fail to open. Sometimes the handle of the energy-isolating device moves, but all the poles remain closed. If the physical break in the power conductors is hidden from view, the worker must assume that an electrically safe work condition has not been established and he/she may therefore be exposed to energized electrical conductors. When exposed to energized electrical conductors, appropriate protective equipment must be used.
Voltage testing must be conducted to verify the absence of voltage. Testing devices are considered safety equipment and must meet the minimum requirements necessary to measure the expected (possible) voltage. Minimum requirements for test instruments, equipment, and their accessories shall include:
- Appropriately rated for circuits and equipment to which they will be connected;
- Appropriately designed for the environment to which they will be exposed, and for the manner in which they will be used; and
- Properly inspected for external defects and damage prior to use each day.
A person’s life frequently depends on the effectiveness of the voltmeter and using it effectively. Therefore, the device should be of high quality, listed or labeled by a Nationally Recognized Testing Laboratory, protected from damage, inspected frequently, and treated with respect. If a cover of electrical equipment has been removed, then the worker is potentially exposed to electrical conductors and circuit parts that are likely energized. When exposed to energized electrical conductors, appropriate protective equipment must be used in conjunction with the test equipment for the hazards involved with the particular task.
It is necessary to verify the integrity of the voltage-testing device. Satisfactory operation on a known source of voltage should be established first. Then the worker should check for the presence of voltage on all conducting components of the equipment to be worked on. Lastly, the testing device should again be verified on a known voltage source. If the device still functions normally and the absence of voltage was verified, the equipment can be considered to be de-energized.
Temporary grounds should be used and properly installed to provide a convenient path for voltage unintentionally generated or flowing through the conductor while it is being worked on under specific conditions. Grounds should be installed in such a manner as to create a zone of equipotential around the worker to ensure an electrically safe working condition. The use of temporary grounds has a little direct impact on the de-energized condition. They are intended to drain “unexpected” voltage due to capacitance, transformer action, shorts, or atmospheric static discharge away from the work area. Common examples of when temporary grounds are necessary to work on equipment or systems include:
- Outside overhead lines, which can be re-energized by any number of sources;
- Shielded cables installed underground, in a cable tray, or in conduit.
Due to the possibility of large amounts of current flow on the temporary ground, and the need for the ground to remain in place in the event of such current flow, temporary grounds must be constructed per ASTM F 855. Job-made grounds should be avoided due to improper design and materials being used. Temporary grounds must have a fault-duty rating at least equal to the available fault-current capacity at the point in the circuit where it will be installed. Inadequately rated grounds can result in magnetic forces breaking the conductor or connector and whipping it around like a bullwhip.
All grounding clusters that are installed must be removed when the work task is completed. Each one should be assigned a unique identifier, which is recorded when installed. The same record should be reviewed when the grounding cluster is removed.
Elimination of potential energy sources is the primary control for electrical hazards and should be the first consideration when electrical systems are energized at 50 volts or more. An electrically safe work condition (i.e. lockout/tagout) may not be feasible for voltage-testing and diagnostic tasks, in which case administrative controls and appropriate personal protective equipment are required to reduce or minimize the extent of injury in the event of an incident.
It is important to realize, however, that the acts of opening a disconnecting means, measuring for the absence of voltage, visually verifying a physical break in the power conductors, and installing safety grounds all contain some degree of risk because of the potential for an arc-flash event to occur. These acts are all necessary to achieve an electrically safe work condition, and until they are completed, the worker should be wearing personal protective equipment based on the risk assessment conducted.
Only “qualified persons” may work on or near exposed energized electrical systems or conductors. Unqualified persons assisting in the work must be under the direct supervision of a qualified person for the duration of the exposure.
The routine acceptance of working a system energized should not be a risk that Virginia Tech, the department, the electrical worker, or anyone else routinely accepts. Energized parts greater than 50 volts to which an employee might be exposed shall be put into an electrically safe work condition before an employee works on or near them unless work on energized components can be justified.
Note: Tasks that are considered to be diagnostic in nature (i.e. troubleshooting or testing where the equipment/system must be energized in order to perform such tests) are considered to be justified by their nature and do not require documentation via the Energized Electrical Work Assessment. Safe work practices, including appropriate personal protective equipment and tools as determined by the hazard analysis, must be used.
An Energized Electrical Work Permit shall not be required if a qualified person is provided with, and uses, appropriate safe work practices and appropriate personal protective equipment is worn in the following conditions:
- Testing, troubleshooting, and voltage measuring;
- Thermography and visual inspections if the Restricted Approach Boundary is not crossed;
- Access to and egress from an area with energized electrical equipment if no electrical work is performed and the Restricted Approach Boundary is not crossed; and/or
- General housekeeping and miscellaneous non-electrical tasks if the Restricted Approach Boundary is not crossed.
Work that is not diagnostic in nature, where the equipment or system cannot be put into an electrically safe work condition, must be justified in writing via the Energized Electrical Work Assessment. Justification means that the employer can demonstrate that de-energizing introduces additional or increased hazards, or is infeasible due to equipment design or operational limitations. A qualified person may perform work on or near exposed live parts under the following conditions:
- De-energizing the conductors or equipment would result in an increased or additional hazard. Examples include the loss of electrical power to life support equipment, loss of electrical power which could result in an environmental spill, deactivation of emergency alarm systems in an occupied building, or the shutdown of hazardous location ventilation equipment that is in use.
- Note: Lack of illumination is not justification for live work. Temporary lighting must be installed, where necessary.
- De-energizing the conductors or equipment is infeasible due to equipment design or operational limitations. Examples include: performing diagnostics and testing (e.g. start-up or troubleshooting) that can only be performed with the circuit energized or work on circuits that form an integral part of a continuous process that would otherwise need to be completely shut down in order to permit work on one circuit or piece of equipment. This condition is typical of chemical processing plants.
There is a significant difference between infeasible and inconvenient, and the two terms should not be used interchangeably. The inconvenience cannot serve to justify work on or near exposed live parts.
- Note: For voltages less than 50 volts, the decision to de-energize should include consideration of the capacity of the source and any overcurrent protection between the energy source and the worker. Sources of electrical energy less than 50 volts can be hazardous, for instance, control circuits that operate at less than 50 volts could impact process conditions and result in a release of another kind of energy. Even if the capacity of the energy source is limited, the integrity of the circuit could be critical.
Experience suggests that if managers and supervisors are advised that a significant risk of injury exists, they are reluctant to accept that increased risk, and he or she will be more critical of the plan to execute the work. An Energized Electrical Work Assessment must be completed for all work on or near exposed electrical conductors greater than 50 volts, with the exception of diagnostic testing as described above, where an electrically safe work condition cannot be established.
This assessment provides guidance on required analysis and establishes written justification and authorization for live work. It also provides a means of communication between the supervisor and the employees performing the work. View the flow chart for more information.
Section I - Work Request: This section is to be completed by the department being requested to perform the work live. Typically, a Work Order will be requested of Facilities stating the scope of the work and a request to perform it live. The department that will be conducting the work will then initiate the Energized Electrical Work Assessment. It must provide a description of the circuit and equipment to be worked on and its location. It also indicates that the equipment has been requested to be shut down, either until the work has been completed or temporarily while barriers are installed.
Section II - Hazard Analysis: This section is to be completed by the electrical qualified person who will be performing the live work. It includes detailed information regarding the hazards expected to be encountered and protective measures that must be implemented prior to beginning work.
- Results of the shock hazard analysis: A shock hazard analysis determines the voltage to which personnel will be exposed, the boundary requirements, and the personal protective equipment necessary to minimize the possibility of electrical shock. As voltage increases, so does the degree of risk.
- Results of the flash hazard analysis: A flash hazard analysis determines if flame-retardant clothing must be worn by the worker (and the appropriate rating of the clothing), and the location of the arc-flash boundary. If the flash hazard analysis suggests that the intensity of the arc flash could expose a worker to 40 calories per square centimeter (cal/cm2), the work must not be performed unless an electrical safe work condition has been established. If the intensity is greater than 40 cal/cm2, no protective equipment exists that can protect the worker from the intense pressure that also will be produced by the arcing fault.
Section III - Review of Proposed Energized Electrical Work: Once the electrical qualified person has signed the Hazard Analysis section indicating that live work is requested and justified, a final review must be performed by the supervisor, designated safety representative, and departmental management. Where the department does not have a designated safety representative, contact EHS.
If review signatures are not obtained for all three levels, or if all parties are not in agreement, the request to work live is denied. The work must then be performed in an electrically safe work condition (i.e. de-energized) and the date and time for shut down must be coordinated between the department and the electrical qualified person(s) performing the work.
Note: As tasks are evaluated (i.e. an Energized Electrical Work Assessment is completed), file them for future reference so that the information can be used again, provided the work task conditions remain consistent.
Safe Work Practices
Appropriate personal protective equipment must be selected and worn based upon the hazard/risk category for the task to be performed. Electrical protective equipment must be in good condition, worn properly, of the proper type and class for the voltage to be worked with, and currently tested, if required. For general information on equipment selection and program requirements, view Virginia Tech's Personal Protective Equipment Program.
Work on or near overhead lines requires precautions to be taken to prevent employees from contacting lines that are not insulated, guarded or isolated. Where contact is possible, the lines shall be de-energized and visibly grounded at the point of work or suitably guarded by the power distribution company. Workers carrying long objects must have a worker assigned to each end of the object to maintain control of each end.
Proper lighting must be provided for spaces containing exposed energized parts before workers may enter. Insufficient or lack of illumination or any obstruction that blocks his/her view of the work to be performed is not permitted. Do not reach blindly into areas that may contain energized parts.
Confined Space Entry must be in compliance with Virginia Tech's Confined Space Entry Program. In addition, employees working in manholes, vaults, or similar confined or enclosed spaces that contain exposed energized parts must be provided with and must use, protective shields, barriers, or insulating materials as necessary to prevent inadvertent contact with the energized parts. Doors and hinged panels that could swing into an employee and cause him/her to contact exposed energized parts must be secured before work begins.
Conductive materials and equipment that are in contact with any part of an employee’s body must be handled in a manner that will prevent them from contacting exposed energized conductors or circuit parts.
- If an employee must handle long conductive objects, such as metal ducts, pipes, or rods in areas with exposed live parts, then insulation, guarding, and/or approved materials handling techniques must be used to minimize the hazard.
- Employees may not wear conductive articles of jewelry or clothing, such as watchbands, bracelets, rings, key chains, necklaces, metal eye glass frames, metallic aprons, cloth with conductive thread, or metal headgear if they might contact exposed energized parts unless they have been rendered nonconductive.
Housekeeping duties may not be performed close to live parts unless adequate safeguards, such as insulating materials or barriers are used. Electrically conductive cleaning materials, including steel wool, metallic cloth and silicon carbide, as well as conductive liquid solutions may not be used near energized parts unless procedures are followed to prevent contact.
Interlocks shall not be bypassed unless temporarily necessary as determined by the qualified person working on the equipment. The work must comply with the specified procedures for working on or near exposed energized parts. The interlock system must be returned to its operable condition when the work is completed.
Signs/symbols and accident prevention tags must be used whenever necessary to warn employees about electrical hazards that might endanger them. Signs and tags must meet ANSI Z535 requirements.
Barricades shall be used in conjunction with safety signs where it is necessary to prevent or limit employee access to work areas containing live parts. Conductive barricades shall not be used where it might cause an electrical hazard, and barricades should be placed no closer than the Limited Approach Boundary.
Attendants are required where signs and barricades do not provide sufficient warning and protection from electrical hazards. The attendant must keep unqualified employees outside a work area and must remain in the area as long as there is a potential for employees to be exposed to electrical hazards.
Approved: Acceptable to the authority having jurisdiction, which can include an approval process that includes listed and labeled equipment.
Arc-Flash Protection Boundary: When an arc flash hazard exists, an approach limit from an arc source at which incident energy equals 1.2 cal/cm2 (5 J/cm2).
Arc-Rating/ATPV: Arc-thermal performance value refers to the arc rating of flame-resistant clothing, expressed in calories per square centimeter (cal/cm2).
Balaclava: An arc-rated hood that protects the neck and head, except for the facial area of the eyes and nose (similar to a ski mask).
Bare-hand work: A technique of performing work on live parts, after the employee has been raised to the potential of the live part. The expertise necessary to perform this type of work can be acquired only by specialized training.
Barricade: A physical obstruction such as tape, cones, or A-frame-type wood or metal structures intended to provide a warning, and to limit access (to a work area with a hazard, such as exposed, energized electrical components).
Disconnecting means: A rated device, or group of devices or other means, by which the conductors of a circuit can be disconnected from their source of supply. Examples: circuit breakers, rated switches, fuses.
Department of Energy (DOE): The United States Department of Energy.
Diagnostic (testing): See definition for "working on."
Electrical hazard: A dangerous condition such that contact or equipment failure can result in electric shock, arc flash burn, thermal burn, or arc blast injury.
Electrically Safe Work Condition (ESWC): A state in which the conductor or circuit part to be worked on or near has been disconnected from energized parts, locked/tagged in accordance with established standards, tested to ensure the absence of voltage, and grounded if determined necessary.
Enclosure: The case or housing of apparatus, or the fence or walls surrounding an installation to prevent personnel from accidentally contacting energized parts, or to protect the equipment from physical damage.
Energized: Electrically connected to or having a source of voltage.
Energized Electrical Work Permit (EEWP): A formal process for risk assessment and management review of requests to work on energized electrical components, other than diagnostic/testing, where an Electrical Safe Working Condition (ESWC) cannot be established.
Exposed: The circuit is in such a position that, in case of failure of supports or insulation, contact with another circuit may result.
Exposed (to live parts): Capable of being inadvertently touched or approached nearer than a safe distance by a person. It is applied to parts that are not suitably guarded, isolated, or insulated.
Exposed (wiring): On or attached to the surface or behind panels designed to allow access.
FR (flame-resistant) clothing: The property of a material whereby combustion is prevented, terminated, or inhibited following the application of a flaming or non-flaming source of ignition, with or without subsequent removal of the ignition source. FR clothing will have an ATPV expressed in cal/cm2, which can be related to the hazard/risk category. Examples include flame-retardant treated cotton, meta-aramid, para-aramid, and poly-benzimidazole fibers.
Ground fault: An unintentional, electrically conducting connection between an ungrounded conductor of an electrical circuit and the normally non-current-carrying conductors, metallic enclosures, metallic raceways, metallic equipment, or earth.
Guarded: Covered, shielded, fenced, enclosed, or otherwise protected by means of suitable covers, casings, barriers, rails, screens, mats, or platforms to remove the likelihood of approach or contact by persons or objects to a point of danger.
Hazard/risk category: A rating of 1 through 4 indicates the seriousness of the electrical exposure, with 4 being the most serious. Hazard/risk analysis considers both shock and arc flash hazards. Table 130.7(C)(9)(A) is used to relate work tasks to a hazard/risk category rating.
Incident energy: The amount of energy impressed on a surface, a certain distance from the source, generated during an electrical arc event. One of the units used to measure incident energy is calories per centimeter squared (cal/cm2).
Insulated: Separated from other conducting surfaces by a dielectric (including air space) offering high resistance to the passage of current.
Insulated (tools): The tool manufacturer has assigned a voltage rating to the insulating material.
Isolated (as applied to location): Not readily accessible to persons unless special means for access are used.
Labeled: Equipment or materials to which has been attached a label, symbol, or another identifying mark of an organization that is acceptable to the authority having jurisdiction and concerned with product evaluation, that maintains periodic inspection of production of labeled equipment or materials, and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner. For example, UL (Underwriter’s Laboratories) or CSA (Canadian Safety Association).
Limited Approach Boundary (LAB): An approach limit at a distance from an exposed energized electrical conductor or circuit part within which a shock hazard exists.
Listed: Equipment, materials, or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with the evaluation of products or services, that maintains periodic inspection of production of listed equipment or materials or periodic evaluation or services, and whose listing states that the equipment, material, or services either meets appropriate designated standards or has been tested and found suitable for a specified purpose.
Live parts: Energized conductive components.
Meltable clothing: Clothing made from flammable synthetic materials that melt at temperatures below 600ºF, such as acetate, nylon, polyester, polypropylene, and spandex, either alone or in blends. Not permitted to be used when exposed to live electrical hazards.
Mode 1: All (research) operations are conducted in a positively de-energized (i.e. "cold") state.
Mode 2: All (research) manipulative operations of uninsulated parts are conducted with the equipment in a positively de-energized state. When measurements and observation of equipment functions are necessary, the equipment is energized (i.e. "cold to hot") and some, or all, protective barriers are removed and interlocks bypassed.
Mode 3: All (research) manipulative operations are conducted with the equipment fully energized and some or all normal protective barriers removed (i.e. "hot").
Natural fiber clothing: Clothing made from non-melting flammable materials, such as cotton, wool, rayon, or silk. This type of clothing is permitted for hazard/risk categories 0 and 1 provided the flash hazard analysis is 2.0 cal/cm2 or less, and that the fabric will not ignite and continue to burn under the arc exposure hazard conditions to which it will be exposed. Note that these fabrics could ignite and continue to burn on the body, resulting in serious burn injuries; however, clothing that does not melt may be used for low-level arc flash exposures.
Qualified Person: A person trained and knowledgeable of the construction and operation of equipment or a specific work method and be trained to recognize and avoid the electrical hazards that might be present with respect to that equipment or work method.
Repair: See definition for "working on."
Restricted Approach Boundary (RAB): An approach limit at a distance from an exposed energized electrical conductor or circuit part within which there is an increased likelihood of electric shock due to electrical arc-over combined with inadvertent movement.
Shock hazard: A source of possible injury or damage to health associated with current through the body caused by contact or approach to energized electrical conductors or circuit parts.
Switch, isolating: A switch intended for isolating an electric circuit from the source of power. It has no interrupting rating, and it is intended to be operated only after the circuit has been opened by some other means.
Unqualified person: A person who might be exposed to electrical hazards and must be trained to understand how the exposure could occur and how to avoid injury. Examples include office workers, janitors, equipment operators, apprentices, or workers from crafts other than electrical.
Ventricular Fibrillation (V-fib): An abnormal heart rhythm that commonly occurs during heart attacks. The ventricles of the heart are quivering instead of beating rhythmically.
Voltage, Nominal: A nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class (e.g. 120/240 volts, 480Y/277 volts, 600 volts).
Voltage-rated: The maximum use voltages for rubber insulated equipment, such as gloves or sleeves.
Maximum Use Voltage
a-c – rms
Working distance: The distance between a person's face and chest area and a prospective arc source.
Working on: Intentionally coming in contact with energized electrical conductors or circuit parts with the hands, feet, or other body parts, with tools, probes, or with test equipment, regardless of the personal protective equipment (PPE) a person is wearing. There are two categories, per NFPA 70E, of "working on:"Diagnostic (testing) is taking readings or measurements of electrical equipment with approved test equipment that does not require making any physical change to the equipment; and Repair, which is any physical alteration of electrical equipment (such as making or tightening connections, removing or replacing components, etc.).
Working on, or near: Persons within the Restricted Approach Boundary of exposed energized electrical equipment.
Working space: Access and working area around electric equipment to permit ready and safe operation and maintenance. See Table 3.
No. Voltage pens (i.e. non-contact test equipment) may not always detect the presence or absence of voltage due to design and use limitations. They may be useful in some applications, or as a secondary means of verification. Always review the manufacturer's instructions for proper use and restrictions.
Is training mandatory? If so, when? Yes. Persons who use temporary power taps, such as extension cords, power strips, and ground-fault circuit interrupters (GFCI) should complete this training.
Class length: 1 hour
Available online: Yes
When is refresher training required? Every 5 years.
Please see the online class schedule for more information.
Is training mandatory? If so, when? Yes. Persons who work on energized electrical systems operating at 50 volts or more must have this training.
Class length: 3 hours
Available online: No
When is refresher training required? No
Please see the online class schedule for more information.
Contact the Division of Campus Planning, Infrastructure, and Facilities 540-231-4300. In some situations, the department may need to pay to have additional outlets installed.
Contact the Division of Campus Planning, Infrastructure, and Facilities at 540-231-4300.
No. Arc-rated clothing can only provide protection where it separates the wearer from the ignition source. Exposed body parts are completely unprotected and will suffer the same injuries as if the garment had never been worn. Always button sleeves and collars when performing electrical work tasks.
While professional industrial laundry is preferred, home laundry is acceptable provided that the manufacturer's instructions are followed. Instructions may include the use of a mild detergent in warm water and no bleach products used, for example.
Power strips are temporary taps that must be used correctly and safely in any setting. Power strips must be plugged directly into premise receptacles and cannot be plugged into another power strip or extension cord.
Only power strips that are UL approved, provide overcurrent protection, and are grounded may be used on campus. Power strips must be used in accordance with the manufacturer's recommendations, and shall not be overloaded. Most power strips are designed for low-wattage appliances such as lamps, computers, radios, etc. Large appliances, such as refrigerators, microwaves, tools/equipment/machinery should be plugged directly into premise receptacles and not into power strips.
For more information, contact your safety representative or Environmental Health & Safety at 540-231-2341.
All equipment/material shall conform to the latest issue of all applicable standards as established by National Electrical Manufacturer's Association (NEMA), American National Standards Institute (ANSI), and Underwriters' Laboratories, Incorporated (UL) or other Nationally Recognized Testing Laboratories (NRTL) currently listed with the U.S. Department of Labor. All equipment and material, for which there are NEMA, ANSI, UL, or other NRTL standards and listings shall bear the appropriate label of approval for the use intended.
If electrical equipment is not listed or labeled as outlined above, the department making the purchase shall have a review of the equipment be done for conformance with the National Electrical Code (NEC) and any applicable standards by either a testing laboratory, licensed electrical engineer, or comparable authority, or licensed electrician for simpler systems. Such reviews are to be performed in accordance with NFPA 791 and NEC section 110. Any deficiencies identified during this review must be corrected before the equipment is placed in service. A written certification or test report that the equipment is safe to operate must be provided to and maintained by the department. If the equipment is plug-and-cord connected, a copy is to be provided to Environmental Health & Safety. If the equipment will be hard-wired to the building electrical system, a copy shall be provided to the University Building Official. All costs associated with such testing and inspections are the responsibility of the department making the purchase.
Contact Environmental Health & Safety at 540-231-5985 with questions.
An Arc Thermal Protective Value (ATPV) refers to the maximum incident energy (in calories per centimeter squared) that protective equipment can be exposed to and prevent the onset of a second-degree burn. Ratings are based upon the total weight of the fabric. Appropriate clothing ranges from untreated cotton, wool, rayon, or silk materials with a fabric weight of at least 4.5 ounces per square yard to flame retardant (treated) clothing worn in layers.
For specific guidelines, contact Environmental Health & Safety at 540-231-2341.
Current as low as 9 milliamps (a milliamp is a thousandth of an amp) can produce a painful shock. For reference, consider that the standard household circuit operates at 15 amps, and you should see that most electrical circuits in your work area or home should be treated with respect. Current as low as 100 milliamps can be fatal. The voltage threshold for alternating current is 50 volts, and 100 volts for direct current. If these thresholds are met or exceeded, several hazard controls must be implemented.
Review the Virginia Tech Electrical Safety Program. Personnel that has not been formally trained to work on electrical systems may not rewire or work on campus electrical systems. If you do so, you place both yourself and others in your work area at risk for electrical shocks.
Approach distances to energized parts are discussed during Electrical Qualified Person training provided by Environmental Health & Safety or you may contact Robin McCall-Miller at 540-231-2341 or firstname.lastname@example.org for more information.
OSHA requires that persons who install or modify electrical systems must be qualified by training and experience to perform this work safely. The Virginia Uniform Statewide Building Code imposes additional requirements. The regulations issued by the Virginia Department of Professional and Occupational Regulations also impose training and licensing requirements on persons that perform work on electrical systems.
The supervisor is ultimately responsible for assuring that his or her employees perform work in a safe and code-compliant manner. Environmental Health & Safety supports the supervisor in this role by offering both the general awareness and qualified person electrical safety training. Physical plant also assumes an active role in electrical safety by serving as the Building Code Official for the university. The Building Code Official assures that all work performed meets the code requirements, that renovation permits are issued, and that the work is inspected when complete to assure that all systems have been installed correctly. The Building Code Official also assures compliance with University Policy 5405.
Facilities Services maintains the electrical systems in all academic buildings as well as the main electrical distribution systems on campus. Electrical systems within student housing and dining facilities are maintained by Residential and Dining Programs. In leased spaces, these systems may be maintained either by the landlord or the Division of Campus Planning, Infrastructure, and Facilities. Check with the Office of Real Estate Management for specifics on your leased space.
If workers do not have an accurate map (i.e. one-line diagram) of the electrical system, they can be exposed to potential back feeds from alternate sources, energized capacitors, undocumented switching conditions, and unknown voltages, in addition to the problem of not being able to accurately perform lockout/tagout procedures.