5/1 NFPA70E Final
Arc rating is defined in Article 100, in part, as the value attributed to materials that describes their performance with exposure to an electrical arc discharge and is expressed ? . Informational Note No. 1 states, in part, that arc-rated clothing or equipment has been tested for exposure to an electric arc and that flame-resistant (FR) clothing without an arc rating ? been tested for exposure to an electric arc
in cal/cm2 / has not
Article 130 begins with the general requirement stating, in part, that all requirements of Article 130 apply if a(n) ? analysis is completed or if Table 130.7(C)(15)(a), Table 130.7(C)(15)(b), and Table 130.7(C)(15)(c) are used in lieu of an incident energy analysis.
incident energy
Energy-reducing maintenance switching (ERMS) is an option to include on larger ampere rated circuit breakers and fused switches with the objective of ? the arcing fault time duration for some range of arcing fault currents.
reducing
Portable electric equipment used in highly conductive work locations shall be approved for those locations. In job locations where employees are likely to contact or be drenched with water or conductive liquids, ? shall also be used.
ground-fault circuit-interrupter protection for personnel
The appointment of the NFPA 70E Committee was announced on January 7, ? , and was formed to assist ? in preparing electrical safety standards that would serve its requirements.
1976/OSHA
The limited approach boundary distance for a task involving a fixed circuit part operating at 480 volts, nominal, is ? .
3'6"
The arc flash boundary shall be the distance at which the incident energy equals ? .
1.2 cal/cm2
Which is not one of the three IEEE 1584 methods to calculate incident energy and AFB?
Complex matrix method
? is "the state of the electrical equipment considering the manufacturers' instructions, manufacturers' recommendations, and applicable industry codes, standards, and recommended practices."
Condition of maintenance
There are five different common overcurrent protection trip types that a circuit breaker may incorporate. Which type is a newer feature intended to reduce the incident energy exposure if an arcing fault incident occurs while a worker is working on exposed energized conductors? Some are fixed with no adjustment in time-current characteristics, and others have adjustable current pickup settings.
Energy-reducing maintenance switching trip (A)
Which of the following are required to be included on an energized electrical work permit?
III. Justification for why the work must be performed in an energized condition IV. Personal and other protective equipment required by NFPA 70E to safely perform the assigned task and to protect against the shock hazard V. Results of the arc flash risk assessment
What are the two methods stated in NFPA 70E 130.5 for determining the proper arc flash PPE?
Incident energy analysis and arc flash PPE category
NFPA 70E Informative Annex M is titled ? Protective Clothing and Total System Arc Rating.
Layering of
NFPA 70E Article 250 addresses ? and Protective Equipment.
Personal Safety
NFPA 70E Article 245 addresses ? Electric Tools and Equipment
Portable
NFPA 70E Informative Annex O, Safety Related Design Requirements, does not include which of the following concepts?
Safety related design concepts should be considered by the contractor after the electrical equipment has been bought.
GFCI protection devices shall be tested ? .
in accordance with the manufacturer's instructions
Which statement is incorrect? Select one: a. After installation, there is no need to be concerned with an OCPD until the device opens. b. Circuit breakers are mechanical OCPDs that require periodic exercise, inspection, testing, and possible maintenance or replacement. c. Modern current-limiting fuses do not require maintenance other than visual examination and ensuring that there is no damage from external thermal conditions (such as conductor terminations), liquids, or physical abuse. d. The reliability of OCPDs in retaining consistent fault-clearing performance over the system life cycle directly impacts arc-flash hazards.
A
NFPA 70E Article 205 addresses General ? Requirements.
Maintenance
An energized electrical work permit is generally required and documented when working within the limited approach boundary or the arc flash boundary of exposed energized electrical conductors or circuit parts that are not placed in an electrically safe work condition
False
Arc-flash relays can be utilized to sound an alarm when an arcing fault occurs so the worker who is working on the energized equipment can gather his or her tools and get out of the arc flash boundary before being injured.
False
Condition of maintenance is an important electrical safety consideration only for overcurrent protective devices.
False
Determination of an arc flash PPE category for a task performed on DC systems is determined from Table 130.7(C)(15)(a).
False
Personal protective equipment (PPE), such as arc flash protective equipment, shock protection, and head, face, eye, and hearing protection, is covered in 130.7(C). ? protective equipment, such as insulated tools, protective shields, and rubber insulating equipment used for protection from unintentional contact, is covered in ? .
Other / 130.7(D)
According to OSHA 29 Code of Federal Regulations (CFR) 1910.334(b)(2) and NFPA 70E 225.3, which statement below is incorrect when a circuit has been deenergized by a circuit protective device operation due to an overcurrent condition?
Reset the circuit breaker or replace the fuses until smoke discloses the point of the fault. Then, deenergize the circuit and repair the fault.
The employer must implement and document an electrical safety program appropriate to the risk associated with electrical hazards.
True
NFPA 70E informational Note to Table 130.7(C)(15)(a) has the typical fault clearing time for current-limiting fuses as ? .
0.5 cycles when the fault current is within the current limiting range
The 2004 edition of NFPA 70E introduced the requirements of ? . The 2018 edition ? all previous editions.
The energized electrical work permit / supersedes
NFPA 70E 205.4 requires overcurrent protective devices to be maintained in accordance with the manufacturers' instructions or industry consensus standards. In addition, 205.4 requires maintenance, tests, and inspections to be ? .
documented
The job safety planning and job briefing requirements mandate that before starting each job that involves exposure to electrical hazards, the ? must complete a job safety plan and conduct a job briefing with the employees involved.
employee in charge
Only ? persons shall be permitted to work on electrical conductors or circuit parts that have not been put into an electrically safe work condition.
qualified
An Electrical Worker can use the data on a(n) ? electrical equipment and the corresponding service report to determine if the equipment has been tested and inspected within a recommended frequency of maintenance for the type of equipment.
service sticker affixed to
What is the general subject matter of NFPA 70E, Chapter 2?
The maintenance requirements of electrical equipment for worker safety
An unqualified person is defined as a person who is not a qualified person
True
The most common incident energy analysis methods, including equations, are located in NFPA 70E nonmandatory Informative Annex D
True
The requirements of ? shall apply when the arc flash PPE category method is used for the selection of arc flash PPE.
130.7(C)(15)
NFPA 70E, Standard for Electrical Safety in the Workplace, consists of ? chapters; 17 informative annexes; the Foreword to NFPA 70E; and Article 90, Introduction. Chapter 1 is divided into ? articles.
3/5
Only qualified persons are permitted to perform tasks such as testing, troubleshooting, and voltage measuring on electrical equipment operating at voltages equal to or greater than ? .
50 volts
ATPV is defined in ASTM F1959/F1959M as the incident energy (cal/cm2) on a material or a multilayer system of materials that results in a ? probability that sufficient heat transfer through the tested specimen is predicted to cause the onset of a second degree skin burn injury based on the Stoll curve. EBT is defined in ASTM F 1959-06 as the incident energy (cal/cm2) on a material or a material system that results in a ? probability of break open.
50% / 50%
The distance associated with each shock protection approach boundary to exposed energized electrical conductors or circuit parts is determined by the nominal phase-to-phase system voltage range for ? systems and the nominal potential difference for ? voltage systems.
AC / DC
When the energy-reducing maintenance switch (ERMS) of a circuit breaker is switched "on," if an arcing fault event occurs on a circuit protected by the circuit breaker, and the arcing fault current is ? the ERMS current pickup, the circuit breaker trips without intentional delay.
Above
? parts of the body inside the arc flash boundary shall be protected. When arc-rated clothing is worn to protect an employee, it shall cover all ? clothing.
All / ignitible
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-Flash Boundary
The arc flash hazard created during an arc flash event is ? dependent on the OCPD that is protecting the downstream equipment, or the "protecting-OCPD."
Directly
For the purposes of using the arc flash PPE category method to select PPE, different types of OCPDs, such as MCCB, ICCBs, and LVPCBs, are all considered to have the same 1.5 cycle typical fault clearing time in the Informational Note to Table 130.7(C)(15)(a).
False
NFPA 70E Annex F Risk Assessment and Risk Control Sections F.3 and F.4 provide insight to how design concepts and system upgrades can reduce or eliminate electrical hazards. Table F.3, The Hierarchy of Risk Control Methods, lists six Risk Control Methods; the lower the number in this table, the greater the effectiveness in reducing the risk. The design concepts and upgrades discussed pertain to (1) elimination, (2) substitution, and (3) engineering controls in the hierarchy of Table F.3. Safety by design is considered to have less effectiveness than item (6) PPE in the Hierarchy of Risk Control Methods.
False
NFPA 70E informational Note to Table 130.7(C)(15)(a) has the typical fault clearing time for molded case circuit breakers as 3-cycle with an instantaneous integral trip
False
Once an electrical system has been installed and is considered to be an existing system, no safety-related design concepts can be implemented to eliminate or mitigate electrical hazards
False
Overcurrent protective device selection decisions for new systems and for existing system upgrades never affect arc-flash hazards, either positively or negatively.
False
Table 130.7(C)(15)(a) is used to determine whether arc flash PPE is required.
False
The arc flash PPE category can be determined through an incident energy analysis.
False
The following items would meet the protective clothing and personal protective equipment (PPE) requirements for arc flash PPE Category 2, where there is not a need for an arc-rated jacket, parka, rainwear, or hard hat liner: Arc-rated long-sleeve shirt and pants with a minimum arc rating of 8 cal/cm2 Arc-rated faceshield with a minimum arc rating of 8 cal/cm2 Hard hat Safety glasses Hearing protection (ear canal inserts) Heavy duty leather gloves Leather footwear
False
The only purpose of specifying remote monitoring of voltage, current, or measurement of other vital electrical parameters for an electrical control panel or electrical panel is so that the facilities manager or machine operators can see if the equipment is still running properly. It does not provide any safe work practice benefit for the maintenance worker who must troubleshoot equipment while operating.
False
The overcurrent protective devices utilized in panelboards are either LVPCBs or fuses/switches.
False
When conducting an arc flash risk assessment in accordance with 130.5, the "condition of maintenance" is not a consideration.
False
When electrical equipment is subject to a clean and dry environment, cleaning is required more frequently than if the environment is humid with a significant amount of dust and other foreign matter
False
When the energy-reducing maintenance switching (ERMS) option is switched "on" or enabled, the loads on the circuit that the ERMS protects are in energy efficiency mode and energy savings occur.
False
When the fault current is in the current-limiting range of a current-limiting OCPD, the fault current's magnitude and time duration are both increased, which increases the energy released by an arcing fault.
False
When using the arc flash PPE category method (for AC systems), the fault clearing time has to be greater than the fault clearing time parameter value for the type of equipment to be worked on in Table 130.7(C)(15)(a).
False
When using the arc flash PPE category method, the worker must maintain a working distance less than the working distance parameter value for the type of equipment to be worked on in Table 130.7(C)(15)(a).
False
Identify which of the following statement(s) is/are true as they relate to unqualified persons.
I. An unqualified person is defined as a person who is not a qualified person. III. Unqualified persons must be familiar with any electrical safety-related practices necessary for their safety. IV. Unqualified persons must be trained in any electrical safety-related practices necessary for their safety.
Several requirements cover the care and maintenance of arc-rated clothing and arc flash suits. Identify which of the following statements are true as they relate to these requirements.
I. Apparel must be inspected before each use. II. ASTM F 1506 is an example of a standard that contains information on PPE, but it is not a standard that is required to be followed. III. Garments cannot be used where contaminated or damaged to the extent that their protective qualities are impaired. IV. Guidance is provided in ASTM F 1506 when trim, name tags, or logos are affixed to arc-rated garments. V. Manufacturer's instructions for care, maintenance, and cleaning must be followed. VI. The same arc-rated materials used to manufacture the clothing must be used for repair.
Section 130.8 deals with the requirements for work within the limited approach boundary or arc flash boundary of overhead lines. Which of the following are categories of requirements related to this work?
I. Approach Distances for Unqualified Persons II. De-energizing or Guarding III. Determination of Insulation Rating IV. Employer and Employee Responsibility V. Uninsulated and Energized VI. Vehicular and Mechanical Equipment
Which of the following are required to be included on an energized electrical work permit?
I. Arc flash boundary II. Available incident energy at the working distance or arc flash PPE category IV. Personal and other protective equipment required by NFPA 70E to protect against the arc flash hazard V. Results of the shock risk assessment
Which of the following are considerations related to the incident energy analysis method?
I. Arc-rated clothing and other PPE shall be used by the employee based on the incident energy exposure associated with the specific task. II. The incident energy analysis shall take into consideration the characteristics of the overcurrent protective device and its fault clearing time, including its condition of maintenance. III. The incident energy analysis shall be updated when changes occur in the electrical distribution system that could affect the results of the analysis. IV. The incident energy exposure level must be based on the working distance of the employee's face and chest areas from a prospective arc source for the specific task to be performed.
Alerting techniques are located in 130.7 and are therefore a form of protective equipment. Which of the following is/are categories of requirements of alerting techniques?
I. Attendants II. Barricades IV. Safety Signs and Tags
Energized work is generally prohibited. Such work is permitted under which of the following conditions?
I. For energized electrical conductors and circuit parts that operate at less than 50 volts, where the capacity of the source and any overcurrent protection between the energy source and the worker are considered and it is determined that there will be no increased exposure to electrical burns or to explosion due to electric arcs. II. Where the employer can demonstrate that deenergizing introduces additional hazards or increased risk. III. Where the employer can demonstrate that the task to be performed is infeasible in a deenergized state due to equipment design or operational limitations.
In addition to meeting other requirements, such as those in 130.7(C)(7) and 130.7(C)(14), which of the following are accurate statements related to the requirements for hand protection used as arc flash protective equipment?
I. Heavy-duty leather gloves or arc-rated gloves must be worn where required for arc flash protection. IV. Where insulating rubber gloves are used for shock protection, leather protectors must be worn over the rubber gloves.
The electrical safety training requirements in 110.2(A) state that employees are required to be trained in a number of topics. Which of the following are among those employee training topics?
I. In safety-related work practices and procedural requirements, as necessary, to provide protection from the electrical hazards associated with their respective job or task assignments III. To identify and understand the relationship between electrical hazards and possible injury IV. To understand the specific hazards associated with electrical energy
The employer must document that each employee has received the training required by 110.2(A). This documentation of training must satisfy which of the following criteria?
I. It must be made when the employee demonstrates proficiency in the work practices involved. II. It must be maintained for the duration of the employee's employment. III. It must contain the content of the training, each employee's name, and dates of training
Several factors must be considered in the selection of protective clothing. Coverage is one of these factors, and includes which of the following?
I. Jackets must be closed at the neck. II. Shirts must be closed at the neck .III. Shirt sleeves must be fastened at the wrists. IV. Shirts must be tucked into pants
Which of the following statements are true for tasks performed on energized equipment in panelboards or other equipment rated greater than 240 volts and up to 600 volts within the parameters of Table 130.7(C)(15)(a) when arc flash PPE is required?
I. Parameters include a maximum of 25 kA available fault current and a maximum of a two-cycle fault clearing time. IV. Voltage testing would constitute an arc flash PPE category 2, when arc flash PPE is required.
In accordance with the requirements in 130.7(C)(15)(a), Table 130.7(C)(15)(a) is to be used to determine which of the following for AC equipment?
I. The arc flash PPE category
Electrical equipment such as switchboards, panelboards, industrial control panels, meter socket enclosures, and motor control centers that are in other than dwelling units, and that are likely to require examination, adjustment, servicing, or maintenance while energized, must generally be field marked with a label. Which of the following information must be contained on the label where a label is required?
I. The arc flash boundary VI. The site-specific level of PPE
Determine which of the following among the NFPA 70E requirements relate to qualified person training, both generally and when such persons are permitted to work within the limited approach boundary.
I. The employee must be familiar with the proper use of the special precautionary techniques, applicable electrical policies and procedures, PPE, insulating and shielding materials, and insulated tools and test equipment. II. The employee must be trained in the skills and techniques necessary to determine the nominal voltage of exposed energized electrical conductors and circuit parts. III. The employee must be trained to select an appropriate test instrument and demonstrate how to use the correct device to verify the absence of voltage. IV. The employer must determine that each employee is complying with the safety-related work practices required by NFPA 70E through regular supervision or inspections conducted on at least an annual basis. V. The decision-making process necessary to be able to select the appropriate risk control methods from the hierarchy of controls identified in 110.1(G), including PPE, must be followed.
Which of the following are required by the 130.7(B) provisions addressing the care of protective equipment?
I. The protective equipment must be maintained in a safe, clean, and reliable condition and in accordance with manufacturer's instructions. II. The protective equipment must be stored in a manner to prevent damage from physically damaging conditions and from moisture, dust, or other deteriorating agents. IV. The protective equipment must be visually inspected before each use.
A shock risk assessment is required to be performed for which of the following reasons?
I. To determine if additional protective measures are required, including the use of PPE III. To estimate the likelihood of occurrence of injury or damage to health and the potential severity of injury or damage to health IV. To identify shock hazards
When adding a circuit breaker to a panel or replacing a circuit breaker, it is imperative to ensure that the circuit breaker is suitable for that panel and the circuit breaker has the proper ? and equivalent short-circuit performance.
I. ampere ratingII. interrupting ratingIII. voltage rating
In addition to meeting other requirements, such as those in 130.7(C)(3) and 130.7(C)(14), head protection must also meet which of the following arc flash protective head protection requirements?
II. An arc-rated balaclava with an arc-rated faceshield is an option when the back of the head is within the arc flash boundary and the anticipated incident energy exposure is 12 cal/cm2 or less. IV. An arc-rated hood shall be permitted to be used instead of an arc-rated faceshield and balaclava combination unless the anticipated incident energy exposure exceeds 12 cal/cm2.
Determine which of the following are required to meet the NFPA 70E requirements related to emergency response training.
II. Employees exposed to shock hazards and those responsible for the safe release of victims from contact with exposed energized electrical conductors or circuit parts shall be trained in methods of safe release. III. Employees responsible for responding to medical emergencies shall be trained in first aid and emergency procedures. IV. Employers shall verify at least annually that employee emergency response training is current. V. The employer shall document that emergency response training has occurred.
Which of the following are required to be included on an energized electrical work permit?
II. Energized work approval signature(s) III. Evidence of completion of a job briefing, including a discussion of any job-specific hazards IV. Means employed to restrict the access of unqualified persons from the work area
The scope of the 2018 NFPA 70E includes:
II. Safety related maintenance practices III. Safety related work practices IV. Other administrative controls
? is a component of an arc flash risk assessment used to predict the incident energy of an arc flash for a specified set of conditions.
Incident energy analysis
There are five different common overcurrent protection trip types that a circuit breaker may incorporate. Which type is intended for all types of fault current conditions? In this case, the circuit breaker opens as fast as it can, and the exact speed depends on the design. This trip current pickup setting can be fixed or adjustable.
Instantaneous trip (I)
An approach limit at a distance from an exposed energized electrical conductor or circuit part within which a shock hazard exists
Limited Approach Boundary
The 1995 edition of NFPA 70E included the concepts of ? and the establishment of an arc. The 2000 edition continued to focus on establishment of flash protection boundaries, the use of personal protective equipment, and ? to assist the user in applying appropriate protective clothing and personal protective equipment for common tasks.
Limits of Approach/Charts
There are five different common overcurrent protection trip types that a circuit breaker may incorporate. Which type is intended for overcurrents that can persist for many seconds to minutes without damaging the conductors or electrical equipment and is considered overload and low-level fault protection?
Long-time trip (L)
NFPA 70E Chapter 2 addresses Safety-Related ? Requirements, and Chapter 3 addresses Safety Requirements for ? Equipment.
Maintenance / Special
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
Restricted Approach Boundary
The arc flash PPE category method can be used to determine the AFB and the selection of arc flash PPE, if specific conditions and parameters are met. In general terms, which is not a parameter that must be satisfied to use the arc flash PPE category method?
The incident energy at 18" working distance shall not exceed 8 cal/cm2.
The physical location of a motor disconnecting means has a bearing on the implementation of lockout/tagout. What is not a suitable location for a within-sight motor disconnecting means per NEC 430.102?
The motor disconnect is located by the door when entering a space with a motor, and it is not within the line of sight of the motor or more than 50 feet from the motor
A poorly or improperly maintained OCPD can result in higher actual incident energy during an arc flash incident than determined by an incident energy analysis.
True
After a circuit breaker interrupts a fault, it might not be suitable for further service.
True
An electrical safety program in compliance with NFPA 70E must include a risk assessment procedure that addresses the potential for human error and its negative consequences on people, processes, the work environment, and equipment.
True
An unqualified person is never permitted to cross the restricted approach boundary.
True
Appropriate safety-related work practices shall be determined before any person is exposed to the electrical hazards involved by using both shock risk assessment and arc flash risk assessment.
True
Energy-reducing maintenance switching options can be included with many new circuit breakers and are available to be retrofitted to many existing installed circuit breakers.
True
Explanatory material is included in the form of informational notes, which are not enforceable as requirements. Brackets containing section references to another NFPA document are for informational purposes only and are provided as a guide to indicate the source of the extracted text.
True
Facility operating and local conditions can vary to such an extent that the actual maintenance schedule should be tailored to the environment where the equipment is located.
True
Finger-safe products may reduce the likelihood of an electrical shock hazard. Some component products with finger-safe IP20 claims have a "conditional" IP20 rating. For example, some conductor terminations may be considered IP20 rated if a conductor of a specific AWG is prepared and installed in the terminal properly.
True
Garments worn as outer layers over arc-rated clothing, such as jackets or rainwear, shall also be made from arc-rated material.
True
If a circuit breaker or switch has not been operated in its normal service, a periodic open-close exercise should be planned.
True
If an Electrical Worker is working on energized equipment when justified and wearing arc flash PPE per NFPA 70E 130.5 incident energy analysis, and if the overcurrent protective device fails to operate as designed, or does not operate, the incident energy that the Electrical Worker will be exposed to may be much higher than calculated.
True
If the incident energy for an actual arc-flash event is higher than the incident energy calculated as part of the arc-flash risk assessment, the Electrical Worker may not be wearing sufficient PPE. In addition, workers who thought they were outside the arc-flash boundary may be wearing flammable garments which may be now subject to clothing ignition and other unanticipated consequences.
True
Informational Note No. 2 located after Table 130.5(C) provides the rationale that improper or inadequate maintenance may result in the protecting-OCPD taking longer to clear the fault current than its specified published clearing time.
True
Maintenance of all electrical equipment that may be worked on when not in an electrically safe work condition is important for electrical safety.
True
NFPA 70E mandates that the employer's electrical safety program include consideration for condition of maintenance of electrical equipment and systems.
True
The shock protection approach boundary distances are the distances from exposed energized electrical conductors or circuit parts to the employee.
True
The term exposed movable conductor is normally applied to overhead line conductors supported by poles.
True
Under fault conditions, current-limiting fuses have the ability to limit the current let-through to less than the available fault current and clear the fault current in 1/2 cycle or less. The combination of decreased clearing times and reduced arcing current can greatly reduce the incident energy when the arcing current is within the current-limiting range.
True
When testing fuses, whether by resistance measurement or voltage measurement, the test probes should contact the metal end caps of ferrule fuses and the blades on knife-blade fuses.
True
When using IEEE 1584 Guide for Performing Arc Flash Hazard Calculations for the incident energy analysis method, available fault currents should be calculated for all the various scenarios, such as different switch scenarios and motors running and not running scenarios.
True
When using the arc flash PPE category method (for AC systems), the estimated available fault current at the equipment to be worked on must be equal to or less than the available fault current parameter value for the type of equipment in Table 130.7(C)(15)(a).
True
Whenever system changes occur in a premise or changes are made by the utility that might increase the available fault currents, the existing OCPDs must be reevaluated to determine whether they have a sufficient interrupting rating.
True
Where equipment is not properly installed or maintained, PPE selection based on incident energy analysis or the PPE category method might not provide adequate protection from arc flash hazards.
True
Working within the limited approach boundary at voltages equal to or greater than 50 volts is generally prohibited while alertness is recognizably impaired.
True
Incident energy is defined as the amount of thermal energy impressed on a surface, a certain distance from the source, generated during an electrical arc event. Incident energy is typically expressed in ?
calories per centimeter squared (cal/cm2)
An electrical hazard is defined as a dangerous condition such that contact or ? can result in electric shock, arc flash burn, thermal burn, or ? .
equipment failure / arc blast injury
An arc flash hazard is defined in Article 100 as a source of possible injury or damage to health associated with the release of energy caused by an electric arc. Informational Note No. 1 indicates that the likelihood of occurrence of an arc flash incident increases when energized electrical conductors or circuit parts are exposed or when they are within equipment in a(n) ? condition, provided a person is interacting with the equipment in such a manner that could cause an electric arc. An arc flash incident is not likely to occur under normal operating conditions when enclosed energized equipment has been properly installed and ?
guarded or enclosed / maintained
One of the conditions where energized electrical conductors and circuit parts operating at voltages equal to or greater than 50 volts shall be put into an electrically safe work condition before an employee performs work is where the employee is within the ? boundary
limited approach
The ? and the ? the current flows are ? related to the energy released by an arcing fault.
magnitude of the arcing fault current / length of time for which / directly
NFPA 70E Chapter 1 applies generally to electrical safety in the workplace. Chapter 2 addresses safety-related ? requirements. Chapter 3 ? Chapter 1 with safety requirements for special equipment.
maintenance / supplements or modifies
A qualified person is defined as one who has demonstrated skills and knowledge related to the construction and ? of electrical equipment and installations, and has received safety training to ? the hazards and reduce the associated risk.
operation / identify
The electrical safety program must identify the ? upon which it is based, the ? by which it is measured and monitored, and the ? to be utilized before work is started by employees exposed to an electrical hazard
principles / controls / procedures
When an employee works in a confined or enclosed space that contains exposed energized electrical conductors or circuit parts operating at voltages equal to or greater than 50 volts or where an electrical hazard exists, protective shields, protective barriers, or insulating materials must be ? as necessary to avoid inadvertent contact with these parts and the effects of the electrical hazards
provided by the employer and used by the employee
The informational note to 130.7(A) informs that, even when protection is selected in accordance with the PPE requirements of 130.7, some situations could result in burns to the skin, although burn injury should be ? .
reduced and survivable
When racking a circuit breaker, an extended-length racking tool or a remote operated motorized racking tool can be used to move the worker farther from the potential arcing fault source or outside the arc-flash boundary, providing ? .
safer work practices
Maintenance in NFPA 70E is intended for preserving or restoring the condition of electrical power systems equipment or devices for ? . Electrical safety is directly tied to the ? of electrical power systems equipment.
the safety of employees exposed to electrical hazards / condition of maintenance
In many cases, the incident energy exposures at equipment of existing fusible systems can be reduced by ? .
upgrading Class H, K5, K9, and RK5 fuses to Class RK1 fuses
Which of the following are identified as categories of requirements related to precautions for personnel activities?
I. Alertness II. Anticipating Failure III. Blind Reaching IV. Conductive Articles Being Worn VII. Illumination VIII. Reclosing Circuits After Protective Device Operation IX. Routine Opening and Closing of Circuits
The requirements that address host and contract employer's responsibilities require a number of things. Which of the following are among those requirements?
1. The contract employer must ensure that each employee follows the work practices required by NFPA 70E in addition to any safety-related work rules of the host employer. IV. The host employer must inform the contract employer with the information about the employer's installation that the contract employer needs to make the assessments required by Chapter 1 of NFPA 70E V. There must be a documented meeting between the host employer and the contract employer where the host employer has knowledge of hazards covered by NFPA 70E that are related to the contract employer's work.
The Informational Note to the definition of arc flash boundary states that, according to the Stoll skin burn injury model, the onset of a second degree burn on unprotected skin is likely to occur at an exposure of ? for one second.
1.2 cal/cm2
The limited approach boundary distance for an overhead line conductor operating at 480 volts, nominal, is ? .
10'
What Annex in NFPA 70E provides information on various calculation methods to determine the AFB and incident energy?
Annex D
A qualified person is never permitted to cross the restricted approach boundary.
False
According to NFPA 70E 210.5, it is not necessary to maintain protective devices to ensure that they can adequately withstand and interrupt available fault current
False
Article 130, Work Involving Electrical Hazards, by definition, covers work involving four hazards caused by either proximity or equipment failure.
False
NFPA 70E Informative Annex H is titled Requirements for the Selection of Protective Clothing and Other Personal Protective Equipment
False
NFPA 70E requires protective equipment as necessary. It also requires that much of this protective equipment conform to applicable state, federal, or local codes and standards. Identify which of the following statements are true as they relate to standards that protective equipment must meet.
II. Other protective equipment standards are identified in Table 130.7(G) Informational Note: Standards on Other Protective Equipment. III. Personal protective equipment standards are identified in Table 130.7(C)(14) Informational Note: Standards for Personal Protective Equipment.
Which of the following is/are the recognized methods for the selection of protective clothing and other PPE where work will be performed within the arc flash boundary?
III. Arc flash PPE category IV. Incident energy analysis
? provides some frequency of maintenance guidelines as well as guidelines for setting up an electrical preventive maintenance (EPM) program, including sample forms and requirements for electrical system maintenance.
NFPA 70B: Recommended Practice for Electrical Equipment Maintenance
The principle in ? is to eliminate or minimize electrical hazards before a worker ever has a chance to become exposed to them.
designing for safety
NFPA 70E 225.3 requires a circuit breaker that has interrupted a fault approaching its interrupting rating to be ? in accordance with the manufacturer's instructions.
inspected and tested
Test instruments, equipment, and their accessories are required to be rated for circuits and equipment to which they will be connected. UL 61010-1, 1, Safety Requirements for Electrical Equipment for Measurement, Control, and Laboratory Use - Part 1: General Requirements, addresses rating and design requirements for voltage measurement and test instruments intended for use on electrical systems ? and below.
1000 volts
Table ? is used to determine protective clothing and PPE to be used when working within the arc flash boundary based on the determined arc flash PPE category. Arc-rated clothing with a minimum arc rating of ? is required for arc flash PPE Category 2.
130.7(C)(15)(c) / 8 cal/cm2
In the IEEE paper "Prioritize Circuit Breaker and Protective Relay Maintenance Using an Arc Flash Hazard Assessment," the study determined that if the closest upstream circuit breaker or relay did not operate and the next higher level upstream OCPD cleared the arcing fault current, in approximately ? of the cases, the worker would not have adequate arc rated PPE.
2/3
